All posts by Dmitry Filipoff

Fighting DMO, Pt. 4: Weapons Depletion and the Last-Ditch Salvo Dynamic

Read Part 1 on defining distributed maritime operations.
Read Part 2 on anti-ship firepower and U.S. shortfalls.
Read Part 3 on assembling massed fires and modern fleet tactics.

By Dmitry Filipoff

Introduction

Modern naval combat can consist of forces firing dozens if not hundreds of missiles at one another’s fleets and salvos. These volumes of fire can be unleashed within mere minutes as forces look to launch offensive and defensive salvos that are large and dense enough to kill and defend warships. Yet these sophisticated weapons are available in limited numbers and require long lead times to produce.1 Only a fraction of these inventories are available for immediate use given how the magazines of the operating force’s platforms are distinct from the weapon stocks they draw from. Militaries can be limited to using the weapon stocks they had shortly before conflict broke out, and a short conflict may be decided by what was mainly fielded in platform magazines. Unless the conflict becomes especially prolonged and the industrial base grows significantly, the inventory of precision weapons will steadily diminish and pose critical constraints. A core operational challenge is how to carefully manage weapons depletion while still unleashing massed fires.

Weapons depletion is in its own right a powerful force for shaping warfighting behavior and securing major operational advantage. The larger consequences of depletion can include steep decreases in unit availability and overall operations tempo on a theater-wide scale. This challenge is especially severe for the U.S. Navy given how long it would take a depleted U.S. warship to travel out of a Pacific battlespace, rearm in safe havens, and return to the fight.2 In a short, sharp conflict featuring intense salvo exchanges, a warship that depletes itself only once may very well miss the rest of the war.

The concentration and distribution of a force will flex and evolve as its platforms suffer depletion. As commanders look to employ mass fires, they must be mindful of how to spread depletion across the force, how to interpret the adversary’s expenditures, and how inventory pressures can be manipulated through the last-ditch salvo dynamic.

Distribution and Depletion

One of the critical advantages of massing fires from distributed forces is the ability to more effectively manage depletion. A distributed force fielding a vast array of overlapping firepower makes for an especially large and shared magazine. This offers a much greater chance of mustering enough firepower to overwhelm robust defenses while achieving a better spread of depletion. Depletion can be spread across a broader scope of platforms and occur more gradually across the force, rather than all at once for individual strike platforms and force packages. Spreading depletion prolongs distribution, because every depleted asset makes the remaining force less distributed and more concentrated.

Some platforms and force packages certainly have sufficiently deep magazines to launch large enough volumes of fire on their own, with less of a need for outside contributing salvos. But large standalone salvos diminish a core tenet of distribution – maintaining many spread out threats to complicate adversary targeting. Forces that fire large standalone salvos can quickly give away that they just depleted most of their offensive firepower, reducing their value as targets and diminishing the distribution of the broader force.

The more a platform has to discharge a large number of missiles to contribute fires, the more easily an adversary can ascertain the composition and depth of their remaining inventory. A U.S. destroyer that fires 30-40 Maritime Strike Tomahawks in a single large salvo can give away that it has little remaining long-range anti-ship weaponry. By comparison, massing fires from a broader array of distributed forces makes it harder for an adversary to ascertain when platforms and formations have depleted their individual magazines.

Aggregation allows firepower to be combined in smaller portions from individual launch platforms. Ideally each launch platform can afford to expend only a small fraction of its magazine at a time, if many other platforms are doing the same with proper timing and coordination. Individual platforms will be able to sustain distributed offensive threats for longer than if they had fired off large, independent salvos of their own.

However, as inventory begins to dwindle across a distributed force, mass fires can cause larger portions of the force to reach the end of their magazines around a similar timeframe. This could radically collapse the offensive posture and capability of the distributed fleet if not carefully managed. By delaying magazine depletion at the individual platform level, mass fires risk magazine depletion across a broader portion of the force at a later time.

Consider a fleet that has four distributed warships available for contributing fires. If one warship emptied its entire offensive inventory per strike, then the remaining force becomes increasingly concentrated and predictable as to where the next several strikes may come from. Instead, if those four warships combine fires to launch a quarter of their offensive inventory per strike, the distributed force posture endures for more time and across more attacks. But all of those warships would deplete at a similar time, triggering a larger drop in force distribution compared to depleting only one platform per strike through the first scheme. By spreading depletion to prolong distribution, mass fires trade smaller decreases in distribution earlier in the fight in exchange for larger decreases later on.

Having deeper magazines or more strike platforms reduces the share of magazine depth each attacker must deplete to contribute to mass fires, and further delays the broader depletion of the force. A distributed force posture can be preserved by having a large number of assets with overlapping firepower, or rotating assets quickly enough to replace those that have depleted their magazines. The goal is to maintain enough available firepower over time so the distribution of the force can endure.

Asymmetric Weapons Depletion and Operational Risk

There are important asymmetries in how warships can deplete their offensive missile firepower versus their defensive firepower. One asymmetry is that commanders may be deeply uncomfortable keeping large surface warships in the battlespace when they are low on defensive firepower but fuller on offensive firepower compared to the reverse situation. Another key asymmetry is that defensive firepower is mostly drawn from the local magazines of the naval forces under attack, while offensive firepower can be drawn from the many magazines of a broader distributed force. Leveraging these key asymmetries can secure operational advantage.

Even if a ship survives an intense attack, being on the wrong side of firing effectively first can take the form of being low on defensive firepower while still full on unused offensive firepower. These units can still remain offensive threats, but the volume of fire required to overwhelm their defenses is substantially lowered. This can force commanders to pull these units out of the fight for the sake of survival and replenishing their defenses.

In this sense, firing effectively first is not only defined by scoring successful hits and kills, it can also mean depleting enough of the adversary’s defenses that commanders no longer feel confident in pressing their attack or maintaining warships in a contested battlespace. If those depleted warships are in escort roles and are responsible for defending other ships, then those ships could be forced to withdraw as well. By depleting defensive firepower to the point that warships must be withdrawn before they can attack, those warships’ offensive inventory can be removed from the fight before it can be used, thereby suffering depletion indirectly.

The battle of nerves in naval salvo warfare is partly a function of accepting risk for the sake of minimizing weapons depletion. A more efficient missile exchange tolerates more risk, demanding stronger nerves on the part of commanders. Otherwise, the desire to build more confidence into offensive or defensive engagements can make commanders waste their munitions. A defending warship that fires too many anti-air weapons per incoming missile wants to bolster its odds of near-term survival, but it can deplete itself earlier than warranted and increase risk in follow-on engagements. A warship that fires an excessive amount of anti-ship weapons can risk too much overkill and leave it with little offensive capability for later in the fight.

But commanders who attempt to precisely optimize their offensive salvos in a bid to just barely overwhelm targets with enough fire will risk much greater uncertainty than those willing to accept overkill by expending more volume. Indeed in a form of combat featuring salvos with dozens of missiles that only need to strike a single hit, overkill is more likely than not. Instead, it is the degree of overkill that separates what is sufficient from what is wasteful. Achieving a small degree of offensive overkill can be the more efficient outcome, since attacking with an insufficient volume of fire can lead to waste by making follow-on salvos once again pay the price of breaking through strong defenses to threaten a target. With too much overkill, a unit or commander witnessing a heavy volume of fire pouring into a dead or dying friendly warship may take some small satisfaction in knowing the enemy just suffered depletion far out of proportion to their target.

A key asymmetry is how the risk of depletion through overkill is much more manageable for offensive fires because of the greater ability to mass those weapons from across many forces. Defensive inventory has far less margin to work with because of the isolating effect of the radar horizon on ship self-defense, where there is little ability for ships to leverage a broader shared magazine against sea-skimming threats. An attack on a naval formation can consist of fires pulled from a wide variety of forces, but the formation will often have only its own magazine to defend itself. And with that magazine, the formation may not only have to match the incoming volume of fire, but exceed it to ensure survival. Matching the attacking volume with only one interceptor fired per incoming missile may not be enough to confidently survive a dynamic where a warship cannot afford to take a single hit, yet the attacker can afford to have every attacking missile take a hit except one.

For defensive volume of fire, there can be a thin line between what is sufficiently dense and what is wastefully excessive. Firing just one more interceptor per incoming missile can dramatically increase expenditure in a single engagement and result in a warship facing follow-on threats with a far more depleted magazine. But as mentioned, defensive depletion not only increases risk to the individual platform, it threatens to take that platform’s offensive fires out of the fight prematurely. The broader offensive inventory that is available for massed fires can therefore be threatened by the localized manner of defensive engagements and their especially depleting nature.

Range advantages convert to depletion advantages, where forces with longer-ranged weapons can inflict asymmetric depletion against their shorter-ranged opponents. These threatening dynamics are more probable for navies that can be up against anti-ship weapons with much greater ranges than their own, such as the current range disparity the U.S. Navy is suffering against many Chinese anti-ship missiles.

If two opposing forces have a major disparity in the range of anti-ship weapons, then the forces with less range can be forced to travel hundreds of miles while under fire before they can finally be in a position to attack. These warships can be depleting their defensive firepower while still pressing forward in an increasingly risky bid to bring their offensive firepower to bear. By comparison, the longer-ranged side will deplete far fewer defenses to make their attacks, if they have to deplete those defenses at all. Warships with a significant offensive range advantage are not only in a much better position to fire first, they can fire their salvos and then simply reverse course to keep themselves out of reach while preserving their defensive firepower. The outranged fleet can be pressing forward without much of its defensive firepower left, while the other fleet can be in the much more comfortable position of pulling back with most of its defensive firepower remaining. It is unlikely that the fleet with shorter-ranged weapons would be in a position to catch up to the opposition in many circumstances. Because of the vast distances involved and the large speed differential between anti-ship missiles and warships, it seems improbable that surface warships will run each other down on the open ocean in the age of missile warfare. 

Increased payload range can also translate into increased reload speed, where shifting more of the burden of maneuver onto the payload shortens the logistical lifeline of the platform. The longer the range of the weapon, the less the platform has to travel between its launch areas and rearmament points, shortening the episodic drops in force distribution while offering higher rates of fire. This effect is especially potent for aviation, such as how aircraft firing JASSMs at 230 miles can have much lower reload rates and availability of fires compared to aircraft firing the 1,000-mile extreme range variant of JASSM (Figure 1).3 An asymmetry in weapon range between opposing forces can translate into asymmetry in reload speeds, and make the distribution of a force more resilient against depletion than its adversary’s.

Figure 1. Reverse range rings centered on Taiwan illustrate the area from which targets on the island can be fired upon by 1,000-mile and 230-mile variants of JASSM. Aircraft firing the longer-ranged variant can benefit from shorter journeys between launch points and airbases, such as those on Guam, allowing for quicker rearmament, more enduring force distribution, and higher rates of fire. (Author graphic)

Massed Fires and Uneven Depletion Across Platform Types

As waves of massed fires ensue, the distribution of depletion across the platforms of a force can become uneven. A distributed force may prefer to prioritize its longest-ranged fires, its most common weapons, or other payloads for other reasons, which depletes the specific platforms that launch them. This sets the stage for operational tradeoffs and an evolving risk profile, since one type of platform’s fires can preserve the inventory of another’s, and different platforms have different magazine depths and timeframes for reloading. Uneven depletion can gradually shift the burden of massing fires onto platforms that must assume more risk to continue the fight, encouraging a force to carefully consider how to distribute weapons depletion across platforms over time.

The anti-ship Tomahawk will offer long range and broad magazine depth across many platforms, making it an ideal weapon for massing fires. But heavily prioritizing the use of the anti-ship Tomahawk can make surface forces and submarines among the first to deplete their anti-ship missile inventories, and where these platforms can take many days to reload and return to the fight. The weapons that can contribute the most to mass fires can suffer the most depletion, putting the distribution of the force at risk down the line.

As the fight continues and warships become more depleted, more of the U.S. burden of assembling mass fires against warships can gradually accrue to aviation because aviation can reload much faster than warships. This is especially true for carrier air wings, and carriers have the deepest magazines of all afloat combatants, potentially making them the last warships standing when it comes to remaining inventory after intense exchanges.4 Yet this would pose an especially concentrated posture to an adversary and force air wings to take major risks in deploying the remaining firepower. Preserving the anti-ship inventory of warships is therefore critical in forestalling a need to rely more heavily on aviation-based strikes, which would tie down numerous aircraft to muster volume of fire, pull carriers deeper into the battlespace, and assume more risk.

Yet this relationship is paradoxical. Preserving warship-based inventory can also take the form of leaning more on aviation fires earlier in the fight. Therefore a balance can be defined between the proportion of fires to come from different platform types at different phases of the fight, in order to manage how the risk profile of depletion evolves. A commander that carefully balances a combination of air wing depletion and warship depletion earlier in the fight can better delay the prospect of air wings shouldering more of the burden. Or a commander could heavily favor bombers in the opening phases, which can preserve warship-based fires for later phases, which preserves carriers. Depletion does not necessarily mean firing options have to get far worse as time goes on, depending on how commanders balance risk with regard to what combinations of launch platforms they favor depleting at different periods of the fight.

Submarines offer one of the most critical advantages in managing depletion through the highly favorable tradeoffs that come with sinking ships with torpedoes instead of missiles. The undersea domain is far less saturated with warship defenses compared to above the waterline. The cost of a missile salvo large enough to credibly threaten a group of several warships could easily exceed $100 million and require expending dozens of missiles.5 Credibly threatening the same group would require only several torpedoes, which could cost ten percent or less of the missile salvo.6 A single lethal torpedo strike can substitute for the dozens of missiles that could be required to overwhelm the same warship from above water.

By sailing far into contested littorals and laying near ports, bases, and maritime chokepoints, submarines are much more likely to be in a position to sink ships with fuller magazines compared to other platforms and deprive the adversary of inventory. However, closing the distance for torpedo strikes increases risks to submarines. The operational implications include weighing tradeoffs in the amount of risk commanders are willing to accept for their valuable submarines, versus the risk that could be incurred by depleting the broader missile magazine of the distributed force. Risking submarines in torpedo attacks can spare broader missile inventory and vice versa.

Aircraft and ground-based launchers certainly carry far fewer missiles per loadout compared to a large surface warship. Their shallower magazine depth substantially shortens the interval between launching fires and reloading, even if each of their fires is limited to a few missiles. But these platforms can typically access weapons stocks to rearm at a fraction of the time it takes a warship to do the same. Their shallow magazine depth can make their availability for fires more episodic than warships, but their episodes of depletion are not nearly as steep or prolonged. Land-based forces in the form of Chinese launchers on the mainland would have particularly more endurance than expeditionary stand-in forces that heavily depend on lengthy logistical lifelines to sustain their fires in a long fight.

The nature of uneven depletion will make for especially challenging command decisions. Commanders may face pressure to maintain depleted assets in the fight for the sake of posing some semblance of a distributed posture to the adversary. Commanders weighing such decisions would have to consider whether the adversary’s tracking of expenditure may have been accurate enough to provide the critical insight that portions of the distributed force are depleted. Operational behavior may significantly change based on one’s estimate of an adversary’s depletion and if asymmetric depletion has emerged between opposing forces.

Tracking adversary depletion is a critical operational imperative, but the desire to understand the specific composition and volume of missile salvos can place major demands on ISR and decision-making. Forces may struggle to distinguish between different types of anti-ship or anti-air missiles at long range and in the midst of battle. But knowing the type of launch platform narrows down the potential type of fires, where the tracking challenge is simplified by how certain weapons are exclusive to certain kinds of platforms. An F/A-18 firing on a warship is most likely firing Harpoons or LRASMs, and a Chinese warship firing on a ship is most likely firing YJ-83s or YJ-18s. Weapons that have longer range and are compatible with a broader variety of launch platforms will complicate the adversary’s ability to track expenditure and form estimates of depletion.

Defying Destruction and the Last-Ditch Salvo Dynamic

The adage of “firing effectively first” may be better described as striking effectively first, since two opposing naval formations can still destroy each other even if one fires after the other. In defining what it means to fire effectively first, an ideal kill of a warship or platform can include putting it out of action before it had a chance to use its offensive firepower. Similar to how it would be ideal to destroy a carrier while it is still embarking its air wing, it is ideal to destroy a warship before it has depleted its magazine of offensive missiles. This creates profound psychological and operational pressures that come into play when commanders of individual platforms and formations feel on the cusp of being destroyed. The critical phenomenon of last-ditch fires can threaten to destabilize distributed fleets and massed fires.

Commanders can be extraordinarily pressured to unleash most if not all of their offensive firepower if they believe there is a real risk of imminent destruction. Once a ship or fleet realizes that a potentially fatal salvo is incoming, enormous pressure can quickly force commanders to discharge their offensive firepower soon or else risk losing it permanently. Similar to how a carrier commander would be tempted to launch the air wing before the salvo hits the carrier, warships can make similar decisions with their missile magazines.

Last-ditch salvos are meant to deny the enemy one of the most critical benefits of firing effectively first. Launching a last-ditch salvo right before ships could be destroyed gives those offensive weapons a final chance of somehow contributing to the fight and deprives the adversary the benefit of sinking ships with fuller magazines. Last-ditch fires aim to ensure that archers are never destroyed before they can fire arrows. Concerns over losing limited weapons inventory are sharply intensified by lethal inbound salvos, making the last-ditch salvo a critical protocol for making the most of friendly losses moments before they are incurred.

A last-ditch anti-ship salvo cannot be an act of self-preservation. Commanders can be completely confident that an incoming salvo is dense enough and capable enough to overwhelm their defenses and destroy their warships. Launching their own anti-ship salvo in response is not going to change such an outcome. Anti-ship missiles cannot save warships from anti-ship missiles that are already incoming. These weapons can only save warships from anti-ship missiles that have yet to leave their magazines.

Many platforms that can threaten warships with anti-ship missiles cannot be threatened by those same missiles in return. This creates an asymmetric dynamic where some forces can enhance the effects of distribution by threatening to trigger last-ditch salvos that are futile. Since airborne aviation, submarines, and land-based forces cannot be directly attacked by anti-ship missiles, a warship launching a last-ditch salvo could very well be firing at perceived targets it can do nothing against. Even a single incoming torpedo from a submarine attack could trigger a last-ditch salvo fired in futility. Warships must strive to maintain awareness of candidate targets they can actually threaten with last-ditch salvos if a fatal attack comes from a domain they cannot effectively retaliate in.

A last-ditch salvo may be fired despite a lack of quality targeting information, since the method of simply firing down a line of bearing suggested by the incoming attack may be more than enough for a desperate warship. But warships ideally need broader situational awareness to launch effective last-ditch salvos, and especially to know whether they are under attack by a last ditch salvo themselves. If a warship does not recognize it is facing down a last-ditch salvo and simply reciprocates the attack, it could be firing on a warship with an empty magazine or even a warship that was already destroyed minutes earlier. This is even more wasteful than firing on a depleted warship, and a worthy result for warships whose final actions caused an adversary to waste precious firepower.

Last-ditch salvos are therefore a double-edged sword. This desperate act is meant to prevent precious weapons inventory from being permanently lost, yet this desire can be manipulated to prompt wasteful fires. An adversary can be made to take self-defeating actions in the crucial battle of nerves that infuses salvo warfare.

The simple appearance of an inbound volume of fire can be enough to trigger last-ditch firing protocols. Weapons with longer range and waypointing ability will have more opportunity to feint attacks on the way to their true target, multiplying the combat potential of salvos. If a weapon has enough range, attacking salvos may be waypointed to appear to threaten multiple targets in succession and provoke last-ditch fires from each (Figure 2).

Figure 2. A waypointed salvo triggers last-ditch fires from multiple formations by feinting attacks along the way to its true target. (Author graphic via Nebulous Fleet Command) 

The U.S. may eventually have a substantial advantage in this regard by fielding a cruise missile with especially long range. The Tomahawk has enough range to where a salvo can threaten multiple naval formations through waypointed feints, even if those formations are distributed across hundreds of miles. If several Chinese naval formations are concentrated within 300 miles so they can mass YJ-18 missiles, then it becomes even more feasible to waypoint Tomahawks to trigger last-ditch fires within this radius. If one side’s naval formations have to concentrate within shorter distances to mass their fires, they become more susceptible to this waypointing tactic than their opponents, and they may not even have the range to launch viable last-ditch salvos at all.

Salvos used to trigger last-ditch fires may have to risk a degree of attrition by allowing themselves to be seen by warships. Networked missiles could coordinate pop up maneuvers to rise above the horizon and make themselves known, but only briefly enough before they can be struck by defensive fires. Otherwise the salvo could suffer enough attrition that it loses both its psychological and kinetic potency. Decoy weapons that can project the signatures of multiple aerial contacts, such as the ADM-160 MALD, can be used to inflate the appearance of mass while reducing the ability of defensive fires to chip away at the salvo.7

Two Miniature Air Launch Decoys (ADM-160 MALD) sit side-by-side in the munitions storage area on Barksdale Air Force Base, La., March 21, 2012. (U.S. Air Force photo/Airman 1st Class Micaiah Anthony)

Posing the appearance of significant mass may not be a hard requirement for inducing last-ditch fires from a target. There may be a significant disparity in the volume of fire required to actually kill a platform, versus the volume of fire that is enough to manipulate it into firing prematurely. This disparity can stem from commanders being uncertain about the capability of enemy salvos or their ability to defeat them, or the strain of combat operations taking its toll on decision-making. The last-ditch dynamic can therefore magnify the tactical value of salvos that lack enough volume of fire to destroy targets. Commanders that are limited to local awareness may struggle to differentiate between a small salvo that was only launched as a standalone attack, versus a small salvo that is a harbinger of incoming mass fires. A small salvo can leverage these uncertainties to score outsized tactical benefit by triggering last-ditch fires despite not being able to actually threaten the target. 

Even if a salvo cannot strike a target due to limited range or other constraints, it may still provoke emissions, signatures, and other reactions that could be exploited. Commanders may struggle to distinguish between different types of incoming missiles in real time, where last-ditch salvos consisting of low-capability, short-range, or non-anti-ship weapons can still manipulate reactions. A warship launching a last-ditch salvo could certainly fire its land-attack cruise missiles toward an enemy warship, who either can’t tell the difference or won’t take the chance. The prospect of wresting any sort of non-kinetic benefit can encourage platforms under heavy attack to launch last-ditch salvos regardless of capability or volume of fire.

And non-kinetics can prompt last-ditch fires themselves. Actions such as heavy jamming, blinding attacks against networks, aggressive posturing, and other methods that could be interpreted as a prelude to an imminent attack could also provoke last-ditch salvos. Last-ditch fires can be triggered by much more than just other fires.

The act of firing last-ditch salvos is extremely sensitive to timing given how warship launch cells are often carrying both offensive and defensive firepower, and how some cruise missiles require a minimum amount of lead time to be programmed for launch.8 A warship under attack from a subsonic anti-ship missile fired at a range of 250 miles has barely more than 20 minutes to react. And this assumes the target warship has knowledge of the launch. If the warship becomes aware of the incoming salvo only after it crosses the horizon, it can have roughly two minutes or less to prosecute an intense anti-air engagement while simultaneously discharging the whole of its offensive firepower in a last-ditch salvo. Those final moments would be characterized by an intense outpouring of the ship’s firepower in all-out offensive and defensive warfare. But these vast volumes of firepower would be bottlenecked by the rate of fire, of how many missiles can be fired by a warship’s launch systems in short periods of time. The volume of outgoing offensive and defensive firepower would be diminished as missiles of both types are primarily being fired from the same sets of launch cells, making them compete with each other for brief launch windows.

These challenges can be mitigated by having situational awareness over sea-skimming spaces that go beyond the radar horizon of a warship. Aircraft can provide early warning of incoming salvos and help warship commanders determine whether they must initiate a last-ditch salvo. Effective warning can allow commanders to discharge their last-ditch salvos early enough so that offensive missiles are not competing with defensive missiles for launch windows when it comes time for the warship to defend itself. In any case, warship commanders should strive to have a variety of pre-programmed responses at the ready so they can initiate last-ditch fires as fast as possible, and to have the subjective tactical judgement to know when it is time.

Warships under attack could be forced to fire their final salvos alone and in isolation from the broader distributed force. Yet last-ditch salvos may hardly be enough on their own to overwhelm concentrated defenses. This can put pressure on other combatants and commanders to add contributing fires in the hopes of growing enough volume to credibly threaten targets. A cascading domino effect could threaten to unravel a distributed force’s firepower as last-ditch salvos prompt hasty contributing fires from other platforms. The pressured nature of last-ditch salvos will exacerbate the timing challenges associated with combining fires and potentially rule out a variety of options for growing the volume of fire.

A commander of a distributed force must weigh the risks of attempting to combine fires with a last-ditch salvo. A last-ditch salvo may force a commander’s hand in adding contributing fires to a salvo that was fired on insufficient targeting data, lacks the volume to penetrate defended targets, or features other deficiencies. A commander could hold off on launching contributing fires, conserve the inventory of weapons, and allow the last-ditch salvo to play out on its own. But this may come at the risk of failing to support a salvo that could have effectively put opposing warships out of action if it had received just enough outside fires to tip the scales and cross the thresholds needed to overwhelm defenses. Commanders have to be ready to weigh these options as missile exchanges unfold in real time, and decide if a last-ditch salvo should remain a standalone attack, or leverage it through adding contributing fires.

Conclusion 

As distributed forces unleash massed fires against one another, their desire to decisively overwhelm the opposition will be tempered by the need to minimize depletion. Depletion can threaten to break naval operations and yield major advantage to an adversary. Effectively massing fires from distributed forces can help manage depletion, but the need to achieve overwhelming volume of fire will make this risk a pervasive consideration at all levels of warfare.

Part 5 will focus on missile salvo patterns and maximizing volume of fire.

Dmitry Filipoff is CIMSEC’s Director of Online Content and Community Manager of its naval professional society, the Flotilla. He is the author of the “How the Fleet Forgot to Fight” series and coauthor of “Learning to Win: Using Operational Innovation to Regain the Advantage at Sea against China.” Contact him at [email protected].

References

1. For weapon production lead times, see:

“Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 2 P-1 Line #7, (PDF pg. 94), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

Seth Jones, “Empty Bins in a Wartime Environment: The Challenge to the U.S. Defense Industrial Base,” Center for International and Strategic Studies, pg. 14, January 2023, https://csis-website-prod.s3.amazonaws.com/s3fs-public/2023-01/230119_Jones_Empty_Bins.pdf?VersionId=mW3OOngwul8V2nR2EHKBYxkpiOzMiS88. 

2. For one example, a warship on a one-way trip and traveling at 20 knots would take nearly two weeks to reach the Philippine Sea from U.S. naval infrastructure in San Diego. This assumes a straight line path, which may be less realistic under wartime conditions.

3. For JASSM range, see:

“AGM-158 Joint Air-to-surface Stand-off Missile (JASSM),” U.S. Air Force, https://www.af.mil/News/Art/igphoto/2000420243/.  

For extreme-range JASSM variant, see:

Brian A. Everstine, “USAF to Start Buying ‘Extreme Range’ JASSMs in 2021, Air & Space Forces Magazine, February 14, 2020, https://www.airandspaceforces.com/usaf-to-start-buying-extreme-range-jassms-in-2021/.

4. Hon. John F. Lehman with Steven Wills, “Where are the Carriers? U.S. National Strategy and the Choices Ahead,” Foreign Policy Research Institute, pg. 67, 73, September 9, 2021, https://www.fpri.org/wp-content/uploads/2021/09/fpri-where-are-the-carriers-.pdf. 

5. At an average unit cost of $3.5 million per missile, a combat credible salvo of about 30 LRASMs yields a volume of fire that costs in excess of $100 million.

For LRASM unit cost, see:

“Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 1 of 10 P-1 Line #16, (PDF pg. 261), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

6. MK 48 MOD 7 torpedoes have an average unit cost of around $5 million, but have far less of a requirement to be salvoed in large numbers because of the less saturated nature of undersea warship defenses.

For MK 48 MOD 7 torpedo cost, see:

“Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 1 of 16 P-1 Line #27, (PDF pg. 351), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

7. “U.S. Airborne Electronic Attack Programs: Background and Issues for Congress,” Congressional Research Service, pg. 16-17, May 14, 2019, https://crsreports.congress.gov/product/pdf/R/R44572. 

8. General Accounting Office, “Cruise Missiles: Proven Capability Should Affect Aircraft and Force Structure Requirements,” GAO/NSIAD-95-116, April 1995, pg. 35-36, https://www.gao.gov/assets/nsiad-95-116.pdf

Newer Tomahawk variants than those discussed above have considerably shorter launch preparation times. See:

“Tomahawk,” Missile Threat CSIS Missile Defense Project, last updated February 23, 2023, https://missilethreat.csis.org/missile/tomahawk/ 

and 

Rear Admiral Edward Masso (ret.), “On The Tomahawk Missile, Congress Must Save The Day,” Forbes, June 10, 2015, https://www.forbes.com/sites/realspin/2015/06/10/on-the-tomahawk-missile-congress-must-save-the-day/?sh=7b86cc956bad

Featured Image: September 3, 2005 – U.S. Navy Sailors aboard the USS Fitzgerald (DDG 62) inspect the MK 41 Vertical Launching System (VLS). (Photo via U.S. National Archives)

Flotilla SITREP: Systemic Naval Cyber Compromise and Contested-Network Warfighting

By Dmitry Filipoff

This month the CIMSEC Warfighting Flotilla will be focusing on information and cyber warfare, and will hold discussions on systemic naval cyber compromise and contested-network warfighting. If you haven’t already, sign up through the form below to become a Flotilla member and receive the invites to our upcoming off-the-record February discussions. The full listings for these upcoming discussions are featured down below.

Last month the Flotilla discussed restoring the warfighting imperative for great power navies, and the role of Marine Corps forces in expeditionary anti-submarine warfare. These candid conversations illuminated useful methods for promoting a stronger warfighting focus while fostering connections between participants.

Feel free to visit the Flotilla homepage to learn more about this community, its activities, and what drives it.

Upcoming March Sessions
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The Threat of Systemic Naval Cyber Compromise

 

Cyber threats are pervasive yet underappreciated. As great powers compete, they can leverage their cyber capabilities to undermine opposing militaries in peacetime, and set the stage for wartime compromise. How can navies grow their awareness of how deeply competitors have penetrated into their systems? What may be the ramifications of pre-positioned cyber capabilities being activated in wartime? Join us to discuss these questions and more as we consider the potential for systemic naval cyber compromise.

Read Ahead: Paralyzed at the Pier: Schrödinger’s Fleet and Systemic Naval Cyber Compromise,” by Tyson Meadors
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Network-Contested Warfighting

 

Modern military forces rely heavily on networks to function. But are these forces doing enough to prepare for when the network is a contested battlespace? Are militaries challenging their own network in simulated crucibles, wargaming, and other venues to ensure warfighters can operate in spite of contested networks? Join us to discuss network-contested warfighting and its implications for force employment and force development. 

Read Ahead: Fighting When the Network Dies,” by Capt. Sam Tangredi (ret.)

Completed February Sessions
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Restoring the Warfighting Imperative

The warfighting focus of great power navies can atrophy when faced with little high-end competition for decades. Without the press of a true competitor to center the organization, unhelpful habits and mindsets can proliferate, and the skills needed to win a hard fight are eclipsed by less consequential matters. In light of renewed great power competition, how can modern navies restore the primacy of the warfighting imperative? How can navies reorient themselves to truly be about winning wars, first and foremost? Join us to discuss these questions and more as we can consider the state of the warfighting imperative and how to elevate it.

Read Ahead: A Warfighting Imperative: Getting Back to Basics for the Navy,” by Capt. Gerard Roncolato (ret.)
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Expeditionary Anti-Submarine Warfare

The need for more ASW capability is rising with the size of competitor ASW fleets. Existing ASW assets may be stretched thin, and could struggle to threaten adversary submarines in decisive littorals. How can the Marine Corps enhance ASW capability in contested environments? How can expeditionary advanced bases and stand-in forces contribute to the ASW mission? Join us to consider the possibilities as we discuss expeditionary ASW.

Read Ahead: Implementing Expeditionary ASW,” by Captain Walker D. Mills, U.S. Marine Corps, Lieutenant Commanders Collin Fox, Dylan “Joose” Phillips-Levine, and Trevor Phillips-Levine, U.S. Navy
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Dmitry Filipoff is CIMSEC’s Director of Online Content and Community Manager of the Warfighting Flotilla. Contact him at [email protected].

Fighting DMO, Pt. 3: Assembling Massed Fires and Modern Fleet Tactics

Read Part 1 on defining distributed maritime operations.
Read Part 2 on anti-ship firepower and U.S. shortfalls.

By Dmitry Filipoff

Massed Fires – A Core Tactic of Distributed Warfighting

A core tactic that operationalizes the concept of concentrating effects without concentrating platforms is combining the missile firepower of widely distributed forces. As various platforms launch weapons, their contributing fires combine to grow an overall aggregate salvo that is directed against a shared target. As commanders look to defeat and defend fleets, their decision-making will be strongly influenced by shaping the potential of these massed fires. These methods of massing missile firepower can form a centerpiece of fleet combat tactics in the modern era.

Because even one missile hit can be enough to put a ship out of action, modern high-end warships tend to emphasize powerful air defenses, which can include anti-air weapons, point defenses, electronic warfare, decoys, and other means. These many defenses significantly drive up the volume of fire needed to overwhelm warships and score hits. This makes the ability to mass anti-ship fires from distributed forces a valuable method for mustering enough volume of fire to threaten naval formations.

The adage of “firing effectively first” has sometimes been based in winning the scouting competition that precedes the launching of fires.1 But one can certainly find the adversary first while not having enough available firepower to overwhelm their defenses. It is possible for opposing naval formations to effectively target one another, but are forced to hold fire until more additional launch platforms are made available to add enough contributing fires. A critical component of firing effectively first is being the first to launch enough volume of fire to overwhelm warship defenses.

The current inventory of only eight Harpoons or Naval Strike Missiles on many U.S. surface combatants is hardly enough to be a credible threat to many modern warships. However, if warships carrying only a few missiles apiece can be credibly augmented by more anti-ship fires delivered by bombers, submarines, and other platforms, then the individual warship presents a much larger and amorphous threat. The individual warship features as part of the greater whole that is the distributed force, because a small salvo launched by one platform could very well mean that more salvos from more platforms are on the way. Warships fielding small loads of missiles cannot be discounted or viewed in isolation from the larger force, which magnifies the threat posed by even lightly-armed combatants. Therefore the ability to mass fires considerably broadens the extent of force distribution in the eyes of the adversary.

Contributing Fires and Aggregation Potential

Massed fires can combine multiple different types of missiles, which can be done for the sake of presenting more distributed threats, preserving certain types of weapon inventory, or making due with whatever firepower is available. However, combining fires from a variety of platforms fielding a variety of weapons will pose challenges. Commanders must understand what characteristics dictate the options for how massed fires can take shape, and how these options affect the distribution and risk profile of their forces.

Each individual act of contributing fires to an aggregating salvo can have a narrow window of opportunity measured in only the tens of seconds.2 Launching too late or too early will amount to launching an entirely separate salvo, and risk having missiles suffer defeat in detail while forsaking the advantages of combining fires. To effectively overwhelm multiple layers of air defenses, the missiles of an aggregated salvo have to tightly overlap the target within a similar timeframe, such as within the critical two-minute timeframe that subsonic sea-skimming missiles are visible to a target warship after they break over the horizon. Coordinated timing is central to concentrating firepower.

Regardless of the range or speed of the types of missiles, they will combine over a target if their time to reach the target is similar. One salvo does not need to physically merge with another salvo on the way to the target so long as their time to reach the target overlaps. However, the firing sequence will be affected by how different missiles have different ranges, and how quickly their speed allows them to travel those ranges. The desired timing of strikes affects the sequencing and availability of distributed launches.

Although contributing fires must overlap the target at a similar time, the fires may not all be launched at a similar time. If the U.S. Navy wanted to fire each type of its anti-ship weapons at the same time and have them strike at the same time, then all launch platforms would have to be roughly within the small 80-mile range of the Harpoon missile. The SM-6 launch platform would be a few dozen miles further out because of the weapon’s greater speed. More realistically, taking advantage of a variety of weapon ranges means distributed forces will be at different distances from the same target, and will have to sequence their launches to combine fires. A core task of assembling massed fires is organizing these firing sequences, and understanding the tactical implications of their design.

A critical factor is how long it takes a type of missile to fly to the limit of its range. Assuming the missile can be targeted out to this distance, the maximum flight time creates thresholds and ceilings for how much opportunity the missile has to combine with other fires. Missiles with longer flight times or longer ranges have more aggregation potential and offer more opportunity to combine with other fires. But if missiles have to be fired from a variety of ranges, then missiles with shorter times-to-target will have to wait on missiles with longer times to combine with them.

The maximum flight time of LRASM is estimated here at slightly less than 40 minutes. 3 If LRASM fires are to combine with a separate salvo, then that salvo must also be 40 minutes away or less from striking the target. Once these two factors come close to overlapping – the time-to-target of the waiting contributing fires and the time-to-target of the traveling aggregated salvo – those contributing fires will then have tens of seconds of opportunity to launch and effectively combine with the salvo. The figures below show roughly how long it takes U.S. anti-ship missiles to travel their maximum ranges at their maximum speeds, highlighting a critical factor of aggregation potential (Figures 1 and 2).

Figure 1. A table of U.S. anti-ship missiles and their estimated maximum flight times.4 (Author graphic)
Figure 2. A map of “reverse” range rings centered on a target warship, demonstrating the relationship between range, aggregation potential, and the listed maximum flight times of U.S. anti-ship missiles. (Author graphic)

If missiles of similar speeds are to be combined to grow the volume of fire, then the weapon with the shorter range must wait for the longer-ranged weapon to close enough distance to make combination possible. When range overlaps, the time-to-target will also overlap for missiles of similar speed. Once the longer-ranged weapon aligns with the range of the shorter-ranged weapon, then the latter can be launched to combine fires. If a Harpoon salvo is to combine with a Tomahawk salvo, then the Harpoon launchers must wait for the Tomahawk salvo to be 80 miles or less away from the target to be able to combine with the salvo.

Assuming launch platforms will try to make the most of the range of their weapons, platforms firing Tomahawk will often fire first and platforms launching any other U.S. anti-ship missile will be firing much later in the firing sequence. By necessity those other platforms will have to be much closer to the target than those firing Tomahawk. They could have to wait as long as an hour or more for a Tomahawk salvo to get close enough for them to combine fires.

Combining weapons of widely differing speeds can require limiting tactical opportunities to create a viable firing sequence and achieve a larger volume of fire. The fastest weapons will often have to be fired last in sequence so they can catch up to slower weapons within the narrow timeframe of overlapping the target (Figure 3). The platforms with the fastest weapons will often have to wait the longest to fire, even though they may face the greatest pressures and opportunities to fire first. The potential of capitalizing on a faster weapon’s ability to strike a target earlier can be constrained by the need to combine with slower weapons to achieve enough volume of fire. This constraint stems from the relatively rare nature of the fastest weapons and how subsonic missiles are more common. Otherwise, firing salvos wholly composed of the most high-end and faster missiles can be especially expensive, depleting, and a less distributed form of massing firepower.

Consider how when firing an SM-6 missile in a standalone attack, a target can have as little as four or less minutes of potential warning against the incoming strike. But when SM-6 is a part of contributing fires, the missile’s launch platform will be forced to wait until the aggregated salvo is around four or less minutes away from striking before the SM-6 can be fired.

Figure 3. Click to expand. Three warships launch contributing fires of equal speed that surpass a fourth warship (USS Arleigh Burke). The fourth warship is still able to combine fires by using missiles of higher speed. (Author graphic via Nebulous Fleet Command)

But faster weapons offer many advantages, such as how they can help an aggregating salvo recover from failing or failed strikes. They can be quick enough to be inserted into an active firing sequence, giving commanders flexible options to augment the salvo as it is unfolding. If contributing fires are destroyed on the way to the target, high-speed weapons can be fired to recover lost volume and bolster the salvo into overwhelming dimensions (Figure 4). If a salvo is defeated by defenses, but those defenses were heavily depleted of anti-air weapons in the process, then high-speed weapons can quickly seize the opportunity to finish the target. Faster weapons can also spare commanders from the lengthier process of organizing fires from slower weapons when needed. 

Figure 4. Click to expand. Faster missiles are used to recover lost volume of fire after a set of slower contributing fires suffer attrition. (Author graphic via Nebulous Fleet Command)

Yet in the context of a massed firing sequence, even if a platform fields the fastest missile, it could be the last to fire. It may have to wait the longest even though it could hit the earliest. The longer a platform has to wait for its turn in the firing sequence, the more opportunity the adversary will have to preemptively attack the archer before it can contribute its fires. As commanders organize mass fires, they must be wary of the predictability of their firing sequences and the risk of suffering interruptive strikes. 

The Risks of Predictability and Interruptive Strikes

The way a distributed posture is presented to an adversary will flex and evolve during the course of a mass firing sequence. As an aggregating salvo closes in on a target, the options for growing the volume of fire will narrow, and the remaining distribution of potential launch platforms becomes increasingly concentrated. These dynamics simplify some of the adversary’s targeting challenges, where a force will strive for broad-area awareness partly to understand how an adversary’s massed fires are coming together and pinpoint opportunities to disrupt the firing sequence as it is unfolding.

The staggered nature of building an aggregated salvo from sequenced fires increases the risk to friendly platforms whose contributing fires come later in the firing sequence. If an adversary discovers that standoff fires are being launched against them from distant forces, they may view closer forces as pressing targets demanding immediate strikes. Those closer forces are potential candidates for contributing to the volume of the incoming salvo. They could be archers waiting their turn. By targeting these forces before the salvo gets close enough to be combined with, a defender can preemptively destroy platforms to restrict the growth of the salvo and kill targets with fuller magazines (Figure 5).

Figure 5. Click to expand. Sensing a mass firing sequence, an adversary launches high-speed missiles at a pair of warships it believes will soon add contributing fires. (Author graphic via Nebulous Fleet Command)

When a firing sequence is initiated and an aggregated salvo is born, the burden of destroying archers before they fire arrows considerably intensifies. But those distributed archers must realize that a friendly salvo fired by someone else can make them prime targets of opportunity. If a platform has to wait an hour or more to combine fires with a Tomahawk salvo, then that can offer plenty of time for them to be preemptively attacked by an adversary. The earlier a platform can launch in the firing sequence, the more it reduces its attractiveness for preemptive strikes during the course of assembling massed fires.

The process of assembling massed fires will take on a much more predictable pattern when most of a military’s anti-ship missiles have similar speeds, such as the U.S. military’s mostly subsonic arsenal. In this case an aggregated salvo can take the predictable pattern of gradually building in volume as it closes the range to the target. The outermost platforms initiate the strike by firing the longest-ranged weapons, then platforms closer to the target and with shorter-ranged missiles contribute their fires in turn. As the aggregated salvo closes the distance, each platform that becomes further away from the target than the salvo can be ruled out as a candidate for adding more contributing fires. The potential scope of remaining fires and launch platforms predictably shrinks as the aggregated salvo gets closer to the target. As the salvo closes the distance, the resulting distribution of potential contributors becomes tighter and more concentrated, making clearer to the adversary which archers may remain (Figure 6). 

Figure 6. Click to expand. A mass firing sequence takes on a predictable pattern of aggregation by using missiles of similar speed. (Author graphic via Nebulous Fleet Command)

This predictability can be mitigated through several measures, including by combining fires with weapons featuring widely different speeds. Platforms with faster weapons can remain a candidate for contributing fires even if they are further away from the target than the aggregated salvo, which helps preserve force distribution as the salvo closes in (Figure 7). An adversary that sees an incoming salvo of Tomahawks 100 miles away can rule out that any platform well beyond that range cannot add further Tomahawks to that salvo. But warships 150 miles away can still pose a threat by launching SM-6s that are fast enough to catch up to the Tomahawks and combine over the target in the final minutes.

Figure 7. Click to expand. A mass firing sequence takes on a less predictable form of aggregation by combining missiles of mixed speeds. (Author graphic via Nebulous Fleet Command)

In a similar vein, Chinese forces firing subsonic anti-ship weapons can still have ballistic and hypersonic missiles combine with their fires, despite those faster weapons being launched from positions that are potentially hundreds of miles behind the platforms firing the subsonic weapons. Weapons with a combination of extremely long range and high speed can be on call to rapidly combine with a large variety of other salvos on a theater-wide scale. Forces fielding weapons with a variety of speeds therefore present more complex forms of distribution that make it more difficult to predict how their contributing fires can come together. 

Waypointing is a critical tactic that can make aggregation less predictable and complicate an adversary’s options for preemptively striking waiting archers. Weapons with both long range and long flight times can allow commanders to program waypoints into flight paths to artificially increase the time-to-target and therefore lengthen the opportunity to combine fires. Waypointing can allow platforms closer to the target to launch their contributing fires earlier than if they had simply waited for their time-to-target to overlap with the traveling aggregated salvo.

Consider a warship that is waiting to contribute fires to a salvo that is 30 minutes further away from striking a target than the warship’s own fires. Waypointing can allow that warship to fire immediately and make up the time difference through nonlinear flight paths (Figure 8). This tactic of waypointing contributing fires can allow warships to deprive adversaries of the opportunity to destroy archers before they fire arrows, even if those archers can have a shorter time-to-target than the salvos they are aggregating with.

Figure 8. Click to expand. A pair of warships much closer to the target than distant platforms uses waypointing to launch early in the firing sequence while still aligning the time-to-target with the other contributing fires. (Author graphic via Nebulous Fleet Command)

When contributing fires consist of weapons with similar speeds, the methods of waypointing and in-flight retargeting can allow those salvos to not only combine over the target, but to also merge together on the way to the target. By selectively merging contributing fires and creating more distinct masses earlier in the firing sequence, an attacker can manipulate an adversary’s perceptions and lure defensive airpower toward certain directions. Merging contributing fires can make an adversary falsely perceive that a given formation fired a larger salvo than is actually the case, which can create illusions of greater force concentration and magazine depletion (Figure 9). An adversary may believe a formation is more heavily armed and concentrated than previously believed and redirect more attention toward it. Or the adversary could believe the formation has diminished its value as a potential target by assuming it depleted much of its offensive firepower, and redirect attention away from it.

Figure 9. Click to expand. Two naval formations of several warships use waypointing to give the impression that a large standalone salvo was fired from the vicinity of a single warship (USS Mustin). (Author graphic via Nebulous Fleet Command)

By offering the ability to artificially increase the time-to-target, waypointing allows a force to make its firing sequences much more unpredictable in how they unfold. The path a waypointed salvo can take to the target is not linear, making it unclear to the adversary when exactly the salvo may arrive, what it is targeting, and what other contributing fires it may combine with. A sequence of waypointed fires may not predictably grow an aggregated salvo from the outside in. Rather, each platform uses waypointing to align its contributing fires with the time-to-target of other salvos that are being fired from a variety of ranges and are taking a variety of paths to the target. Through waypointing, the order of the firing sequence is no longer purely defined by who is farther or closer to a target, complicating the adversary’s ability to set priorities for interruptive strikes. This method is potentially one of waypointing’s most powerful force multipliers for enhancing distribution.

Figure 10. Click to expand. Distributed forces launch a mass firing sequence that consists entirely of waypointed salvos. (Author graphic via Nebulous Fleet Command)

Creative methods of assembling massed fires are not only useful for producing overwhelming firepower, but for manipulating the adversary’s interpretations of massed fires for tactical effect. In line with the fundamental tenets of distributed warfighting, missile waypointing is a valuable means of challenging an adversary through complex threat presentations.

Distributing Volume of Fire Across Time

At what point in the firing sequence will the aggregated salvo take on enough volume to be overwhelming? As various contributing fires are launched during the course of massed fires, tactical advantage and disadvantage will come into play depending on when exactly the salvo reaches overwhelming volume on its way to the target. Preserving distribution is not only a matter of managing the physical locations of platforms and contributing fires, it is also a matter of distributing launches across points in time within a firing sequence. Well-distributed launch timing can allow a volume of fire to grow robustly yet unpredictably. Understanding the distribution of launches across time is central toward knowing how to disrupt a massed firing sequence through interruptive strikes and to secure tactical advantage.

A backloaded firing sequence depends on contributing fires to push the aggregate salvo into overwhelming dimensions near the end of the firing sequence. If an aggregated salvo does not reach overwhelming volume until the firing sequence is almost over, then the attack is more fragile and easily disrupted by attacking the contributing fires and waiting archers. A long-range Tomahawk salvo that heavily depends on combining with Harpoon salvos launched by an air wing would take the form of a backloaded firing sequence.

A frontloaded scheme achieves overwhelming volume of fire early in the firing sequence. A large amount of contributing fires are launched early on, but the salvo receives few if any contributing fires for the rest of the firing sequence. The adversary can focus more of their attention and command and control on managing defenses, because a frontloaded firing sequence can spare the adversary the pressure of having to rapidly initiate their own firing sequence in pursuit of interruptive strikes. Multiple warships firing large Tomahawk salvos in tandem and from distant standoff ranges would take the form of a frontloaded firing sequence.

These two schemes of firing sequences frontloaded and backloaded are disadvantaged forms of concentration with respect to timing. Various drawbacks are incurred by concentrating the growth of the volume of fire toward the frontend or backend of a firing sequence. If an adversary confronts a distributed force that repeatedly uses concentrated firing sequences, then distribution is diminished and massed fires become more predictable.

A well-distributed firing sequence makes the growth of the volume of fire less predictable and combines the advantages of frontloaded and backloaded schemes. By achieving high volume of fire early in the sequence like a frontloaded scheme, more contributing fires can be added later to increase the margin of overmatch and ensure the salvo can remain overwhelming. There will be more opportunity for new launches to join the active firing sequence, especially to recover volume of fire if it is lost to attrition or if friendly platforms are preemptively destroyed before they can contribute fires.

By also featuring a meaningful number of launches later in the firing sequence, distributed launch timing can make an adversary believe that both offensive and defensive actions are necessary to restrict the growth of the salvo. They may believe they must preemptively attack waiting archers to interrupt the firing sequence and inhibit the growing volume of fire. Adversaries would feel pressed to defend against missiles while also interrupting an active firing sequence through striking waiting platforms, stretching their decision-making across both offensive and defensive efforts.

A well-distributed firing sequence may be more logistically intensive, where a force would expend enough munitions to achieve overwhelming volume of fire early in the sequence, and still have plenty more launches occur later. This sort of firing pattern is more depleting, but it achieves the critical aim of reducing dependence on launches later in the firing sequence while still leveraging them to enhance distribution and further grow the volume of fire. Ideally an aggregated salvo has enough volume of fire to not only remain overwhelming against enemy defenses, but to also remain overwhelming when multiple friendly archers have been destroyed before they could contribute their planned fires. Launching enough volume of fire to withstand disrupted firing sequences will add to the extreme expense and potential for overkill that characterizes this form of warfare.

The pressure to interrupt an active firing sequence can force commanders to expend more of their fastest and most high-end weapons in interruptive strikes. These weapons can have low enough flight times that they can be fired after an adversary initiates massed fires and still reach targets in time to disrupt the firing sequence. Subsonic salvos by comparison will have far less potential for interruptive strikes. There may be significant opportunity to disrupt the massed fires of the U.S. Navy when its principal land-attack and anti-ship cruise missile will be a weapon that can take almost two hours to travel to the limits of its range, and when China fields anti-ship ballistic missiles of similar range that can reach targets within 15 minutes.5

The distribution of maximum flight times across U.S. anti-ship missiles will make for a more backloaded firing sequence when more weapons have to combine with Tomahawk fires (Figure 11). If Tomahawk is to be fired from near the limits of its range yet still combine with other types of anti-ship weapons, then the launch platforms firing those other weapons will have to wait around an hour before they reach their turn in the firing sequence. A shorter overall firing sequence can be achieved by foregoing Tomahawks and using the other U.S. anti-ship weapons, but those weapons require much denser platform concentration to mass enough fires, especially for air wings. The U.S. can accomplish a well-distributed firing sequence mainly by having enough Tomahawk shooters throughout the battlespace and at widely different ranges from targets, while also leveraging the missile’s potent waypointing and retargeting capabilities. The figures below illustrate different forms of distribution and concentration across firing sequence timelines (Figures 12-14).

Figure 11. Click to expand. A firing sequence timeline depicting the maximum flight times of all U.S. anti-ship missiles, and the earliest each weapon could be fired in a sequence featuring all listed missile types. (Author graphic)
Figure 12. Click to expand. A frontloaded firing sequence achieves an overwhelming volume of fire early in the sequence, but features few if any launches toward the end of the sequence. (Author graphic)
Figure 13. Click to expand. A backloaded firing sequence achieves overwhelming volume of fire only toward the end of the firing sequence. This is more typical of firing sequences that rely more heavily on combining faster weapons with slower weapons, or many short-ranged weapons with fewer long-ranged weapons. (Author graphic)
Figure 14. Click to expand. A well-distributed and robust firing sequence achieves an overwhelming volume of fire early in the sequence. It also continues to add contributing fires throughout the sequence to further reinforce the volume of fire against attrition and sustain distributed firings to further complicate the adversary’s challenge. (Author graphic)

These dynamics create a conundrum for using higher-end weapons. These weapons typically feature very low flight times by virtue of their especially high speed. Their speed will often place them later in the firing sequence where they can combine with more common weapons over the target. Using higher-end weapons is therefore more likely to backload the firing sequence of a mixed salvo. Since the weapons that could contribute the most to a salvo’s lethality would often be fired last, this creates more dependence on ensuring those forces and their kill chains survive until the final minutes of a firing sequence. If those platforms are destroyed or suppressed, or if the handful of high-end missiles are shot down by defenses, then the rest of the aggregated salvo may be at risk of failing and with virtually no time left to add more contributing fires. Counting on higher-end missiles to push a mixed salvo into overwhelming dimensions near the very end of a firing sequence leaves little room to recover lost volume during the course of the attack.

Commanders may not want to risk these dependencies. Therefore they may opt to shorten the overall length of the firing sequence, such as by firing salvos that mainly consist of higher-end weapons. Firing salvos primarily of the fastest weapons will shorten the decision cycle considerably compared to having to wait tens of minutes or longer for more common weapons to form massed fires. A greater number of firing sequences and mass firings could take place within the same span of time it takes to launch a single slower salvo. More than 20 consecutive SM-6 strikes or seven DF-21 anti-ship ballistic missile strikes could be conducted within the time it takes a single Tomahawk salvo to travel the limits of its range (Figure 15). This assumes of course that enough SM-6 and DF-21 inventory is available, targeted, and ready to fire.

Figure 15. Click to expand. Weapons with shorter flight times can cycle through multiple engagements within the same period of time it takes a weapon with a longer flight time to conduct a single engagement. (Author graphic)

Faster weapons can result in a faster kill chain and increase decision-making advantage. A faster kill chain creates more opportunity to launch more attacks, adjust volumes of fire as needed, improve understanding of adversary defenses, and move on to new targets. These advantages may come at a steeper logistical price by depleting high-end inventory at a faster rate. Yet distributed forces that heavily depend on more common weapons with long flight times, like the Tomahawk, may suffer considerable disadvantage in the speed of their decision cycle.

Massing Fires with Aviation

These frameworks for assembling massed fires presume a relatively static laydown of forces from the start to finish of a firing sequence. This is a fairly reasonable assumption when missiles can travel hundreds and even thousands of miles within timeframes that a ship or land vehicle can travel only tens of miles. Most launch platforms will have to rely on the speed and range of their missiles to compensate for their platform’s lack of near-term maneuver in a missile exchange.

Aviation is a critical exception to this. Aviation is the only launch asset whose speed can approach and even exceed that of cruise missiles. The scope of a weapon’s reach can be greatly enhanced by the speed and range of aerial launch platforms, where aviation can put fires in many more places than warships can with similar-ranged weapons in similar timeframes. Through speed and maneuver, aviation can be dynamically repositioned to bolster aggregated salvos in tactically meaningful timeframes. This ability to add flexible on-demand fires makes aviation an especially potent force multiplier for distribution and aggregation. But leveraging aviation poses challenges for assembling massed fires.

First, an important contrast has to be drawn between the availability of fires from carrier air wings, warships, and bombers. One critical advantage carrier aviation has over warships in launching anti-ship strikes is logistics. Carriers have especially deep magazines, and air wings can be rearmed in a matter of hours compared to the days or weeks it can take to rearm warships exiting the theater. But it is quite possible that air wings cannot be armed and sortied quickly enough to satisfy pressing operational demands in a shorter timeframe, such as fitting into a tight firing sequence. It can take a considerable amount of time to finalize mission planning for a large airborne strike, arm dozens of aircraft with specific weapon loadouts, launch those aircraft, assemble the air wing in flight, and then prosecute the strike.7 Aviation-based fires cannot be contributed until planes are loaded and made airborne.

While warships cannot rearm cruise missiles at sea like an air wing can, aviation cannot always match the promptness of warship-launched fires. By fielding weapons within launch cells, warships can fire salvos relatively soon after the decision is made to strike, essentially bypassing some of the steps it would take to deliver similar firepower through aviation.8 Commanders attempting to combine fires from carrier aviation and warships may find the near-term time demands of setting up aviation are constraining quicker options for massing fires. Commanders in need of rapidly deployed firepower may very well opt for warship-based fires over aviation-based ones, and be willing to pay the steeper logistical price of depleting warships in exchange for the earlier application of firepower.

It may be too logistically taxing to keep most of a carrier air wing airborne and on station for the sake of maintaining quicker options for fires. Instead, it is more likely that a carrier air wing would be armed and launched once targets have been definitively selected and the strikes ordered. If enough anti-ship firepower is widely fielded to the point that entire air wings are not necessary to achieve volume of fire, then smaller numbers of carrier aircraft can contribute a fraction of the contributing fires and reduce the time required to prepare aerial strikes. But compared to carrier aircraft, bombers offer a much more stable and enduring source of on-station aerial firepower by virtue of their longer endurance. This on-station endurance can allow bombers to provide options for fires that are more quickly deployed than air wings that need time to prepare and get airborne for massed strikes. The following schemes of assembling massed fires with aviation are more feasible with heavy bombers than full carrier air wings.

Combining fires between ships and aircraft will often depend on how much repositioning aviation needs to set up its contributing fires. But repositioning costs time, where taking advantage of aviation’s high speed to bolster salvos on demand will cost the time it takes to use that speed. That time is also needed to use speed to compensate for how U.S. aircraft are often limited to carrying smaller and shorter-ranged cruise missiles than the ship-launched weapons they can be combining fires with.

The time it costs to reposition aviation can delay massed fires, put aviation later in the firing sequence, and force other platforms to wait on aircraft to move. Flexible repositioning is one of aviation’s greatest potential contributions to massed fires, yet the time it costs to reposition can complicate aggregation and firing sequences. A critical question is how to position aviation in advance to create options for quick and flexible fires.

The extent to which warships are forced to wait on aviation depends on aviation’s position relative to the target and to the friendly warships they are combining fires with. The extent to which aviation will need to reposition after warships initiate the firing sequence mainly depends on aviation’s proximity to the target. Simply put, how do things change if aviation is kept on station in the space between opposing fleets, or when aviation is kept behind friendly fleets?

If aviation is kept behind friendly warships, then warships will often have to wait until enough aviation is assembled and then maneuvered across lines of departure before the warships can initiate the firing sequence with their longer-ranged weapons. Those aircraft may then have much of their ability to maneuver on the way to the target tightly constrained by the need to adhere to the timing of the firing sequence while still having to travel hundreds of miles forward to their launch points.

If aviation is maintained in the space between opposing fleets, then warships can initiate massed fires without having to wait as much for aviation to reposition. In this scheme, the need to reposition aviation can be deferred to the point of it not being a hard prerequisite for initiating the firing sequence. Aviation would have more flexibility to maneuver as needed while the firing sequence is in progress, rather than be locked into a more constrained flight path from the outset and across a longer distance.

Maintaining aviation in the space between opposing fleets will allow massed fires to be initiated earlier. But aviation positioned in this space may be deprived of the valuable air defense and sensing support that friendly warships can provide. It can also be more risky to maintain an aloft presence with aerial tanking in such a forward position, and protecting strike aircraft in a forward position could create substantial air defense requirements for carrier air wings and other aircraft. But unless aviation has missiles with similar ranges and flight times as the larger warship-based weapons, a force that wants quicker options for massing firepower will accept more risk to aviation by maintaining aerial presence in the space between opposing fleets.

Regardless of where they are maintained in the battlespace, once strikes are ordered, aviation will often need to go far beyond the protections of friendly warships that can fire from much longer standoff ranges. If a bomber with LRASM needs to combine fires with a nearby warship’s 800-mile-long Tomahawk strike, that bomber could have to travel 500 or more miles deeper into the contested battlespace before it can launch its own weapons. While other contributing salvos are in flight, aviation will have to be traveling deeper into the battlespace until the necessary time factors overlap so they can add their own fires. This challenge can be greatly mitigated by fielding larger or more capable cruise missiles that can shift more burden of maneuver from the platform to the payload, such as by equipping bombers with Tomahawks or extreme-range JASSMs. This would allow aviation to fire from more flexible standoffs ranges that are comparable to that of warships.

December 6, 1979 – A left side view of a B-52 bomber releasing an AGM-109 Tomahawk air-launched cruise missile. (Photo via U.S. National Archives)

The disposition of aviation would be constrained by the relationship between the speed of the aircraft and the speed of the missiles they are combining fires with. In the U.S. military, many of the bombers and cruise missiles have similar subsonic speeds. Subsonic bombers like the B-52, B-2, and B-21 have fewer options for aggregating with subsonic salvos than faster aircraft. Aircraft that can outpace subsonic missiles, such as strike fighters and B-1 bombers, could be held further back and across wider distributions. If commanders are willing to pay the logistical price, they can use supersonic flight to surge these aircraft forward in time to combine fires with slower subsonic salvos.

Conclusion

Assembling massed fires from distributed forces will be a complicated challenge. It will involve mixing and harmonizing the kill chains of different payloads, platforms, communities, and services. Each of these factors comes with a variety of its own dependencies and pitfalls. As the services look to operationalize mass fires, they must be mindful of how too much complexity and too much sensitivity to tight coordination can threaten to yield brittle operational designs.

Part 4 will focus on weapons depletion and the last-ditch salvo dynamic.

Dmitry Filipoff is CIMSEC’s Director of Online Content and Community Manager of its naval professional society, the Flotilla. He is the author of the How the Fleet Forgot to Fight” series and coauthor of “Learning to Win: Using Operational Innovation to Regain the Advantage at Sea against China.” Contact him at [email protected].

References

1. The full quote is as follows: “At sea better scouting – more than maneuver, as much as weapon range, and oftentimes as much as anything else – has determined who would attack not merely effectively, but who would attack decisively first.” 

See: 

Wayne P. Hughes, Jr., Fleet Tactics: Theory and Practice, Naval Institute Press, pg. 173, 1986.

2. For an example on the need of very close timing for a mass firing sequence of anti-ship missiles, see:

Maksim Y. Tokarov, “Kamikazes: The Soviet Legacy,” U.S. Naval War College Review, Volume 1, 67, 2014, pg. 17, https://digital-commons.usnwc.edu/cgi/viewcontent.cgi?article=1247&context=nwc-review

3. This flight time is derived from an estimate of a maximum missile speed of 550mph, or about 9.16 miles per minute, and applying this speed to a maximum missile range of 350 miles.

4. For weapon range, see:

“Options for Fielding Ground-Launched Long-Range Missiles,” Congressional Budget Office, pg. 24, 2020, https://www.cbo.gov/publication/56143.

For 550mph subsonic speed of Tomahawk, see:

“Beyond the Speed of Sound,” pg. 158 (PDF page 166), Arnold Engineering Development Center’s contributions to America’s Air and Space Superiority, United States Air Force, https://www.arnold.af.mil/Portals/49/documents/AFD-100322-069.pdf

5. This estimate is based on the typical flight times of similar intermediate range ballistic missiles. See:

Bruce G. Blair, Harold A. Feiveson and Frank N. von Hippel, “Taking Nuclear Weapons off Hair-Trigger Alert,” Scientific American, November 1997, https://sgs.princeton.edu/sites/default/files/2019-10/blair-feiveson-vonhippel-1997.pdf. 

Dr. Jamie Shea, “1979: The Soviet Union deploys its SS20 missiles and NATO responds,” NATO, March 4, 2009, https://www.nato.int/cps/en/natohq/opinions_139274.htm

Charles Maynes, “Demise of US-Russian Nuclear Treaty Triggers Warnings,” Voice of America, July 31, 2019, https://www.voanews.com/a/usa_demise-us-russian-nuclear-treaty-triggers-warnings/6172981.html

6. This estimate is derived from the flight times listed in Figure 1, where SM-6 has four minutes of flight time, and a Tomahawk missile has a maximum flight time of 110 minutes.

7. For comparisons of times to plan and launch Tomahawk versus carrier air wing strikes, see:

General Accounting Office, “Cruise Missiles: Proven Capability Should Affect Aircraft and Force Structure Requirements,” GAO/NSIAD-95-116, April 1995, pg. 35-36, https://www.gao.gov/assets/nsiad-95-116.pdf

8. General Accounting Office, “Cruise Missiles: Proven Capability Should Affect Aircraft and Force Structure Requirements,” GAO/NSIAD-95-116, April 1995, pg. 35-36, https://www.gao.gov/assets/nsiad-95-116.pdf

Newer Tomahawk variants than those discussed above have considerably shorter launch preparation times. See:

“Tomahawk,” Missile Threat CSIS Missile Defense Project, last updated February 23, 2023, https://missilethreat.csis.org/missile/tomahawk/ 

and 

Rear Admiral Edward Masso (ret.), “On The Tomahawk Missile, Congress Must Save The Day,” Forbes, June 10, 2015, https://www.forbes.com/sites/realspin/2015/06/10/on-the-tomahawk-missile-congress-must-save-the-day/?sh=7b86cc956bad

Featured Image: PACIFIC OCEAN (August 17, 2018) The guided missile destroyer USS Dewey (DDG 105) conducts a tomahawk missile flight test while underway in the western Pacific. (U.S. Navy photo by Mass Communication Specialist 2nd Class Devin M. Langer)

Fighting DMO, Pt. 2: Anti-Ship Firepower and the Major Limits of the American Naval Arsenal

Read Part 1 on defining distributed maritime operations.

By Dmitry Filipoff

Introduction

As navies look to evolve during the missile age, much of their ability to threaten other fleets will come down to how well they can mass missile firepower. The ability to combine fires against warships heavily depends upon the traits of the weapons themselves. These traits offer a valuable framework for defining the aggregation potential of individual weapons and the broader force’s ability to mass fires.

In the following breakdowns of tactical dynamics and weapon capabilities, it should become clear that virtually all of the U.S. military’s current anti-ship missiles are lacking crucial traits that are essential for massing fires. The consequence is a force with few good options for sinking ships with missiles, and how this could remain the case through the next decade. But new game-changing weapons are on the way, and DMO is the concept that is poised to harness a major transformation in the U.S. Navy’s firepower.

How Mass Fires Define Limits of Distribution

There is a fundamental tension in looking to spread forces out yet still combine their firepower. The range of weaponry is a critical factor that limits the extent to which forces can distribute from another while still being able to combine their fires. This core tension between distribution and aggregation has a strong influence over the tactics and dispositions of a distributed force.

Longer-ranged weapons allow for the broader distribution of launch platforms, while shorter-ranged weapons will force greater concentration. This dynamic can be illustrated using range rings that show the area forces must reside within if they are to combine their fires against a shared target. Range rings are typically used to show the range of a weapon and are centered on the weapon’s launch platform. In this different method of using “reverse” range rings (for lack of a better term), the ring is centered on the target, and shows the area from where the target can be hit by a given weapon. In other words, to strike a target within the range of the Tomahawk missile, a launch platform must be within a 1,000-mile ring of the target.1 Other platforms using the same weapon must also be within this ringed area, highlighting the extent of distribution that is possible while still combining fires. By comparison, platforms using SM-6 or Harpoon have to distribute within much tighter spaces to combine fires (Figure 1).

Figure 1. Click to expand. Range rings centered on a target illustrate the scope of distribution that is possible with various weapons while still being able to combine fires. (Author graphic)

Launch platforms using different weapons with different ranges must have the rings overlap with one another, at least by the time their fires are combining over the target. These reverse range rings show how longer-range weapons allow for the broader distribution of launch platforms, and how shorter-range weapons, especially versions of the common Harpoon missile, force much tighter concentration around a target (Figure 2).

Figure 2. Click to expand. “Reverse” range rings featuring all U.S. anti-ship missiles. (Author graphic)

The specific ranges of missiles are strongly affected by their flight profiles and are not always a linear, set amount in practice. Missiles and aircraft that fly higher earn longer range, partly through the thinner air at higher altitudes.2 But this comes at the expense of being more detectable and potentially less survivable. Low altitude sea-skimming flight maximizes the element of surprise at a significant cost to range and fuel economy. Different flight profiles can be programmed into missiles depending on the tactical circumstances, and many anti-ship missiles can be programmed with non-linear flight paths and waypoints.3 It is often unclear in publicly available information what kind of flight profile is associated with the published range of the missile.

These factors make range rings more elastic than they appear. This variability of flight profiles adds another dimension of complexity to combining fires. For the sake of consistency in the graphics used here, it is assumed that all missiles of the same type are using the same flight profile in linear attacks. Another elastic factor is the maximum effective range of a weapon, which is not the same as the maximum flying range. The distance a missile can be effectively targeted can be less than how far the missile can travel. Maximum flying ranges are used here for consistency.

Having long-range weaponry is extremely valuable in modern naval warfare because weapon range helps shifts the burden of maneuver from the slower platform to the faster payload. This advantage is especially critical to navies because of the significant speed differential between ships and missiles. A warship with a short-ranged anti-ship missile would have to maneuver for hours and even days to strike multiple targets spread across an ocean. But a warship with a long-ranged weapon could hold all those same targets at risk simultaneously with no maneuver. A single warship with Tomahawk can hold targets near Luzon, Taiwan, and Okinawa at risk simultaneously, while a ship with SM-6 could only hold one of those areas at risk at a time. The warship with SM-6 would have to spend significant time maneuvering to eventually hold all of these areas at risk, and only in sequence (Figure 3).

Figure 3. Click to expand. Conventional range rings centered on the launch platform highlight the ability of longer-ranged weaponry to hold many more targets at risk simultaneously compared to shorter-ranged weaponry. (Author graphic)

This relationship between range and maneuver highlights the critical dynamic of how one force’s distribution can make the adversary’s stretched thin or concentrated. If one force package has shorter-ranged weapons than its adversary, it has less space it can distribute within and still combine fires. The short-ranged force package is more concentrated than its opposition, and may only be able to threaten one portion of the opposing distributed force at a time, if it can get in range. By comparison, many more elements of the distributed force can hold the shorter-ranged force at risk, and from safer standoff distances. Rings within rings can illustrate how the force with longer-ranged weapons can enjoy a broader distribution and mass firing advantage over a force with less range (Figures 4 and 5).

Figure 4. Click to expand. Reverse range rings centered on a REDFOR ship illustrate the extent of distribution for BLUFOR ships combining fires with SM-6, and the extent of distribution for REDFOR ships combining fires with YJ-18. The BLUFOR ships can only hold one REDFOR ship at risk at a time, if they can get within range, while all REDFOR ships can hold all BLUFOR ships at risk simultaneously. A majority of REDFOR ships can fire from standoff ranges. (Author graphic)
Figure 5. Click to expand. Reverse range rings centered on a BLUFOR ship illustrate the extent of distribution for BLUFOR ships combining fires with Tomahawk, and the extent of distribution for REDFOR ships combining fires with YJ-18. The REDFOR ships can only hold one BLUFOR ship at risk at a time, if they can get within range, while all BLUFOR ships can hold all REDFOR ships at risk simultaneously. A majority of BLUFOR ships can fire from standoff ranges. (Author graphic)

What can be defined as distributed, concentrated, or stretched thin is less a matter of a specific range or density of forces. Rather, it is better understood as a relationship between one’s own capabilities, and how that compares to the relationship between the capabilities of the adversary. A force that believes it is well-distributed could actually be heavily concentrated in the context of an adversary with much longer-ranged capability.

Anti-ship weapons that are specifically designed for multi-role aircraft are often much smaller than warship-based weapons that are fielded in large launch cells, which often causes these aircraft-based weapons to have lesser range. Aircraft can compensate for lesser weapons range with their faster platform maneuver, whereas warships can compensate for their slower platform maneuver with the longer range of their larger weapons. Understanding this relationship between platform maneuver and payload maneuver and how they can complement and compensate for one another is critical to assembling massed fires.

But range is only one critical variable for assessing the ability to mass fires. Other critical traits include launch cell compatibility, platform compatibility, number of weapons procured, and numbers of weapons fielded per platform. These traits combine to highlight the true extent of a navy’s offensive firepower.

Harpoon and the Perils of Carrier Strike

The Harpoon missile was the U.S. Navy’s first anti-ship missile and has remained its primary anti-ship weapon for more than 45 years.4 The way the U.S. Navy has continued to field this missile has created severe operational liabilities for U.S. sea control and the credibility of American security guarantees in the Indo-Pacific writ large. The Harpoon missile underscores a critical capability gap of major strategic significance by highlighting just how little anti-ship missile firepower the U.S. military has. The weapon’s shortcomings are emphasized by the especially risky tactics the U.S. would be forced to use in war to make much use of it.

The Harpoon missile’s greatest weakness comes through its combination of short range at 80 miles for the more common variants and the lack of meaningful inventory in all its compatible launch platforms save for one – aircraft carriers.5 The short range of this missile draws the U.S. Navy’s most expensive and least risk-worthy platform deeper into the battlespace, while funneling carrier air wings into exceedingly concentrated anti-ship attacks. But because the U.S. Navy has lagged for decades in fielding a meaningful replacement for Harpoon, the highly risky method of attacking ships with carrier air wings is the only tactic the U.S. military effectively has for sinking high-end warships at long range.

The Harpoon missile has the broadest platform compatibility of any U.S. anti-ship weapon, where it can be fielded by submarines, surface ships, bombers, land-based launchers (which the U.S. sells to partners but does not procure for itself), and carrier air wings. But despite the U.S. Navy having more than 9,000 vertical launch cells for missiles, the Harpoon is incompatible with these launchers.6 Instead, it has to be kept in torpedo racks or in launchers mounted topside, which are highly uneconomical methods that severely reduce the number of weapons that can be fielded per warship. U.S. Navy destroyers and cruisers only carry eight Harpoon missiles despite having around 100 launch cells per platform, and the number of torpedo tubes per submarine typically numbers in the single digits. What launch cells offer is significant magazine depth on both an individual platform and force-wide basis, making launch cell compatibility a crucial trait for massing fires.

PACIFIC OCEAN (Feb. 18, 2008) Note the four Harpoon missile launchers in the background and the 64 vertical launch cells in the foreground. Original caption: Seaman Robert Paterson, of Norgo, Cal., stands watch next to the aft vertical launch missile platform on the fantail while underway on the guided-missile cruiser USS Lake Erie (CG 70). (U.S. Navy photo by Mass Communication Specialist 2nd Class Michael Hight)

As a general rule of thumb, any alert and modern warship larger than a corvette should be able to hold its own against a salvo of only eight subsonic anti-ship missiles, or else the warship can hardly justify its cost. U.S. surface and submarine launch platforms are hardly able to muster enough volume of fire to credibly threaten most modern warships with their sparse inventories of Harpoon missiles. This shallow magazine depth creates a strong need for massing fires between multiple platforms to achieve enough volume of fire. But the extremely short range of Harpoon means this weapon has barely any potential for aggregation with other ship-launched Harpoon missiles, unless commanders are willing to concentrate numerous warships to an extreme degree.

This combination of launch cell incompatibility and short range in the Navy’s mainstay anti-ship weapon forces carrier aviation to shoulder most of the burden of massing enough volume of fire. Only the air wing can conceivably mass enough platforms to create enough volume of fire, while having a chance of getting those platforms close enough to a target warship to launch a strike. These factors make aircraft carriers the only platform that can muster a combat credible volume of Harpoon fire.

An F/A-18 Hornet can equip up to four Harpoon missiles, where only two of these aircraft can match the Harpoon firepower of a U.S. Navy cruiser or destroyer. But against high-end warships, achieving combat credible volumes of Harpoon fire requires massing large numbers of carrier aircraft. Overwhelming a single surface action group of several modern destroyers, each with dozens of anti-air weapons and several layers of hardkill and softkill defenses, could conceivably require the majority of an air wing. The remaining few aircraft would be thinly stretched between maintaining combat air patrols, providing tanking and jamming support to the striking squadrons, among other roles. By heavily concentrating the burden of massing volume of fire on air wings, those air wings are subsequently stretched thin across a multitude of other critical missions.

Attempting to mass fires with a missile that is very short-ranged creates severe tactical risks. The short range of Harpoon forces an extremely tight and dense concentration of carrier aircraft around the target to muster enough firepower to be overwhelming. Harpoon’s short range also makes it a weapon that cannot always be confidently fired from standoff distances beyond the range of modern air defenses, unlike many anti-ship missiles. Instead, Harpoon can force air wings to concentrate themselves well within the range of opposing shipboard air defenses. Warship air defense weapons, such as China’s HHQ-9B missiles, can approach and even exceed the short ranges of the Harpoon, putting adversaries into the more favorable position of being able to threaten archers before they can fire arrows (Figure 6).7

Figure 6. Click to expand. Harpoon and LRASM reverse range rings centered on a target illustrate the limits of distribution while massing fires. The center ring illustrates the range of the target’s longest-range air defense weapons, showing how Harpoon-equipped aircraft will have to enter within range of these air defense weapons to mass fires. (Author graphic)

Survivability concerns not only apply to carriers, but to their air wings as well. Air wings are highly sensitive to attrition, where losing even a few aircraft per sortie can quickly render certain missions unsustainable. This is especially true for anti-ship missions that require large numbers of aircraft to achieve sufficient volume of fire. The Navy’s air wings can be risking substantial losses by using a missile that is so short ranged that it can force them to send large and tightly concentrated aerial formations into the teeth of modern naval air defenses. The air wing’s ability to mass enough anti-ship firepower would be rendered impotent in a matter of days if not hours by suffering even minor losses on only a few of these risky strikes.

A visualization of aircraft attrition rates. (Graphic via slide deck of “Sharpening the Spear: The Carrier, the Joint Force, and High-End Conflict” by Seth Cropsey, Bryan G. McGrath, and Timothy A. Walton, Hudson Institute, October 2015.)

Carrier air wings may be resisted by far more than warship air defenses. The signature posed by a mass of carrier aircraft heading toward a target at high altitude could provide plenty of warning to vector opposing airpower into position to blunt the strike. Compared to the aircraft defending the airspace, anti-ship squadrons would likely be at a hardpoint and maneuverability disadvantage. Many of their hardpoints would be taken up by a combination of heavy anti-ship weapons and drop tanks, with potentially fewer anti-air weapons loaded compared to the opposing dogfighters. If the anti-ship aircraft are intercepted before they are within range of attacking warships, they may be forced to dogfight and evade missiles while having their maneuverability impacted by the heavy anti-ship weapon loadouts. Drop tanks, anti-air, and anti-ship weapons will compete for similar hardpoints on carrier aircraft, setting the stage for difficult tradeoffs between survivability, concentration, and mustering enough volume of cruise missile fires.

An F/A-18E flying with a varied weapons loadout. (Lockheed Martin photo)

Anti-ship strikes can be conducted near the limits of the air wing’s range to maximize standoff distance. But the short range of Harpoon combined with the relatively short range of current generation carrier aircraft (compared to past and future generations of air wings), forces the carrier deeper into the contested battlespace and potentially incurs more risk. Harpoon not only threatens the tight concentration of valuable carrier aircraft around targets, it threatens to pull the carrier itself deeper into riskier territory.

Extending the range of the air wing through drop tanks or tanking aircraft can help keep the carrier further out, but this will diminish the volume of firepower by devoting hardpoints and aircraft to fuel instead of weapons. This can benefit the survivability of the carriers more than the air wings, where adding range to the air wing can improve the carrier’s survivability by allowing it to launch strikes from further away. But this will do less for the air wing’s survivability because the short range of their anti-ship weapons will still force tight concentration around the target regardless.

When it comes to managing the signatures of aircraft carriers, not only does the signature of the carrier have to be taken into account, but the signature of the air wing as well. The signatures and footprints of air wing operations can contribute toward concealing or revealing the carrier’s location. Maximizing the standoff range of an air wing launching a massed anti-ship strike encourages a more linear flight path to and from the target, a denser concentration of aircraft throughout the flight path, and higher altitude flight that extends the range but increases the detectability of the aircraft. Even though it maximizes standoff distance, a linear flight path could more easily lead an adversary back to the carrier by virtue of predictability.

Shortening the carrier’s range to the target or devoting more hardpoints and aircraft to fueling can give the air wing more margin to increase the complexity of force presentation. It can allow the air wing to more widely distribute itself and take nonlinear paths to and from the target, which can help conceal the carrier’s location (Figure 7). However, ensuring a disaggregated air wing can effectively come together on time to mass fires poses more complex challenges for mission planning compared to a more linear strike, especially when combining fires with other types of platforms. And a distributed nonlinear flight profile may have to come at the cost of decreasing the overall striking range of the carrier and pull it deeper into the battlespace.

Figure 7. Click to expand. A visualization of carrier strike flight profiles, where each flight path is 500 miles from the carrier to the target. A concentrated linear strike has more overall range, but offers less complex force presentation in some respects than a distributed, nonlinear strike. Yet the distributed flight profile shortens the overall range of the carrier’s striking power. (Author graphic)

Overall, many of the survivability concerns and tradeoffs of using air wings and carriers in anti-ship roles are substantially worsened by the Harpoon missile’s traits. But the major advantage Harpoon has over all the other anti-ship weapons in the U.S. arsenal is its inventory numbers. While recent public information on current figures appears unavailable, data from the 1990s suggests an inventory of as many as 6,000 missiles.8 It is reasonable to assume that the figure today remains in the thousands, compared to most other U.S. anti-ship missiles which have been procured only in the hundreds or dozens. But the ability to leverage the depth of the Harpoon inventory is tightly bottlenecked by the shallowness of the individual platform magazines it is fielded in, given its launch cell incompatibility.

Due to the major risks air wings and carriers must take to effectively mass the very short-ranged Harpoon, maybe the Navy’s carriers would be better served by not using this weapon in a fleet-on-fleet fight. Doing so could enhance the survivability of carriers, air wings, and the surface ships that escort them. But it would mean coming to terms with how the vast majority of the U.S. Navy’s force structure and missile arsenal is hardly able to threaten modern naval formations with anti-ship firepower. Virtually all of the U.S. military’s anti-ship capability could then be narrowly confined to what the submarine force can accomplish with torpedoes alone.

One has to be careful about extrapolating specific tactics from basic weapon limits, given how shortcomings in capability can be compensated by creative operational design. Maybe the Navy is counting on the submarine force sinking the adversary’s high-end surface combatants to pave the way for carrier anti-ship strikes, but that will do little against the land-based airpower those carrier aircraft may still have to tangle with.

November 2015 – An F/A-18 armed with a Harpoon Block II+ missile during a free flight test at Point Mugu’s Sea Range in California. (U.S. Navy photo)

This design of having the entirety of the U.S. military’s long-range anti-ship capability completely concentrated in massive aircraft carriers, who must in turn heavily concentrate their valuable air wings to execute the tactic, is extremely contrary to the principle of distribution. What Harpoon tactics reveal is that after severely lagging in anti-ship missile development for more than half a century, the U.S. Navy has deprived itself of many critical options for fighting another great power navy.

SM-6 and Diluting Capability Across Missions

The SM-6 is unique among the Navy’s anti-ship missiles. It is the only supersonic anti-ship weapon in the Navy’s arsenal, it can be used against both aerial and warship targets, and it has the highest production rate of the Navy’s latest generation of anti-ship weapons. Featuring 150 miles of range for the more common variants, it offers a modest improvement of range over the latest Harpoon variants.9 It is also the only Navy shipboard anti-air missile that may be used to aggregate defensive firepower at long range. However, some of the supposed strengths of SM-6 create drawbacks when it comes to massing firepower for anti-ship strikes.

The high speed of the SM-6, which is more than Mach 3, improves the survivability and lethality of the missile when it comes to breaking through warship defenses and striking the target at high speeds.10 However, the high speed of the missile complicates its ability to combine fires with the Navy’s other anti-ship weapons, which are all subsonic. If SM-6 is to combine with subsonic missiles, then it must either be fired near the end of a mass firing sequence to ensure timely overlap, or the platforms firing subsonic missiles must be much closer to the target than the warship firing SM-6. (This dynamic will be discussed more closely in Part 3.)

The multi-mission versatility of the weapon poses challenges for effective mass fires by complicating release authorities. If a distributed force is to combine anti-ship fires across multiple platforms, then the release authority for offensive anti-ship weapons may naturally reside at a higher echelon than the commander of an individual ship, who typically lacks the organic sensors to target these weapons against warships at long range. But the intense speed and lethality of missile attacks on warships means individual commanders should be afforded the authority to prosecute their local air defense missions with great initiative, especially to avoid defeat in detail. If a unit-level commander feels compelled to employ SM-6 for the sake of ship self-defense, then that may diminish a higher-echelon commander’s options for massing anti-ship fires.

The typical flight profile of long-range anti-air weapons poses another challenge to the effectiveness of SM-6 as an anti-ship weapon. While long-range anti-air weapons can certainly hit sea-level targets, their initial phase of flight typically involves a boost phase that takes them to higher altitude.11 Higher altitude makes it easier for the missile to achieve its maximum speed and range before it descends back down to hit lower-altitude threats. However, a higher altitude flight profile creates disadvantages when attacking warships. High-altitude flight broadens the area from which a missile can be detected and engaged from, possibly giving more warships the opportunity to engage the missile and with more time to take multiple shots. Sea-skimming flight by comparison can force air defense engagements into the immediate area of only the target warship. The SM-6 missile’s high speed is not so great that it effectively compensates for these risks of high-altitude flight. The boost phase of an SM-6 launch can give almost double the reaction time to a target warship’s radars compared to a slower subsonic missile that is only detected after it breaks over the target’s horizon.12

It is unclear if SM-6 can be fired on a flatter trajectory and maintain an end-to-end sea-skimming flight profile. Doing so would likely deprive it of a significant amount of range. It would also make it more difficult for the missile to apply the greatest source of its lethality against warships – its high speed. The warheads of anti-air weapons are much smaller than those of purpose-built anti-ship weapons, where the warhead of SM-6 is about only 15 percent of the size of an LRASM or Tomahawk warhead.13 SM-6 needs to reach high speeds to be at its most lethal against warships, but achieving those speeds is heavily dependent on higher-altitude flight profiles that make the missile less survivable.

The U.S. Navy Arleigh-Burke class guided-missile destroyer USS John Paul Jones (DDG-53) launches an SM-6 missile during a live-fire test of the ship’s Aegis weapons system in the Pacific Ocean. (U.S. Navy photo)

The range of SM-6 is not so long that its offensive anti-ship roles can be cleanly separated from its defensive anti-air roles. The concept of “standoff” fires implies that a valuable margin of survivability can be earned by outranging an opponent’s ability to strike back. But the range of many great power anti-ship missiles is great enough to where SM-6 cannot be comfortably used in a purely standoff role for attacking modern warships. If a warship is within range of attacking another high-end warship with SM-6, then it is also likely within range of anti-ship missile threats that could force the ship to expend SM-6 on defense instead. This effect becomes even more relevant when longer-ranged weapons like opposing anti-ship ballistic missiles can cast a long shadow over thousands of miles of ocean.14 Commanders may opt to reserve their most capable air defense weapon for protection against the adversary’s most capable anti-ship missiles.

Because modern anti-ship weapons tend to outrange most anti-air weapons, it is much more feasible to combine offensive firepower than defensive firepower from across distributed forces. SM-6 may mark an exception by using the unique NIFC-CA capability that allows it to be targeted beneath the radar horizon of the launching warship. The range of SM-6, its high speed relative to the subsonic anti-ship missiles it could be used against, and its ability to be retargeted beneath the horizon make the aggregation of defensive firepower possible.15 This is an especially unique capability, but adds more complexity to the command-and-control arrangements undergirding massed fires.

Compared to all of the Navy’s other modern anti-ship missiles (excluding the aging Harpoon), SM-6 has an advantage in being produced at consistent full-rate production for a number of years since being introduced in 2013, with more than 1,300 missiles in the inventory.16 By comparison, all of the Navy’s other latest generation of anti-ship weapons currently exist in very low numbers that make them hardly applicable to the large-scale salvo requirements of modern naval warfare.

However, most of the SM-6 production runs to date have been for earlier variants whose anti-ship ranges are only marginally better than the latest Harpoon variants.17 While longer-ranged versions of SM-6 are forthcoming, the vast majority of the current inventory will offer little improvement in broadening the extent to which warships can distribute and still be able to combine fires.

Even if longer-ranged versions of SM-6 quickly arrive in large numbers, much of the missile’s versatility could have to be set aside to fill the Navy’s critical anti-ship capability gap through the near term. SM-6 is currently the Navy’s only somewhat numerous, launch-cell compatible, and long-range anti-ship weapon. But its multi-mission capabilities threaten to dilute the inventory across diverse threats. The Navy may be forced to maintain SM-6 as its only viable modern anti-ship missile until other anti-ship weapons are produced in large enough numbers to make a real difference and free SM-6 to fulfill its air defense potential. But given how current production runs are trending, this could take at least 10-15 years to accomplish. If the Navy finds itself in a major naval conflict this decade, it may be forced to forego much of SM-6’s cutting edge air defense capability for the sake of retaining a modicum of long-range anti-ship firepower. 

Maritime Strike Tomahawk – The Foundational Enabler of Massed Fires

More than 40 years after an anti-ship Tomahawk first struck a seaborne target in testing, the Navy will be reintroducing an anti-ship variant of the missile.18 More so than any other U.S. anti-ship weapon to be fielded in the coming years, the Maritime Strike Tomahawk holds the greatest promise in fostering a major evolution in the Navy’s ability to distribute platforms and mass anti-ship fires.

Tomahawk’s great advantage is its combination of launch cell compatibility and very long range at more than 1,000 miles.19 Many platforms will be able to carry large numbers of an especially long-range weapon, creating a wide range of options for massing fires. Long range also gives the weapon more opportunity to vary its flight paths and use waypointing, which can be used to execute a variety of tactics and facilitate aggregation with other salvos.

By finally having an anti-ship missile that is both long-range and launch cell compatible, the Navy will be poised to drastically increase the amount of anti-ship firepower across a much greater distribution of platforms. Land-based Tomahawk launchers are also on the way for the U.S. Army and Marine Corps, which will significantly increase options for massing fires if those services procure the weapon in major numbers.20

U.S. Army Mid-Range Capability ground-based missile launcher program. (U.S. Army slide)

However, the Maritime Strike Tomahawk’s potential will not be fully realized until many years from now. It will not reach initial operating capability until 2024 and is currently in its early years of low-rate initial production and testing, with roughly 100 MST kits procured so far.21 The Navy is looking to upgrade all of its Block IV Tomahawks into Block V variants, and it is possible up to 300 recertification kits may be installed per year.22 But it is unclear if every recertification will also add the maritime strike capability through the specific Block Va configuration.23

At this rate, it could take 10 or more years before the Navy has enough inventory of the foundational missile that will allow it to truly make distributed and massed anti-ship fires a reality.

Jan. 27, 2015 – A Tomahawk cruise missile hits a moving maritime target after being launched from the USS Kidd (DDG-100) near San Nicolas Island in California. (U.S. Navy video)

LRASM – A Leap Forward Yet Still More of the Same

The Long-Range Anti-Ship Missile (LRASM) will mark an important upgrade to the Navy’s anti-ship firepower. Featuring a stealthy profile and an estimated range of around 350 miles, LRASM outranges all of the Navy’s other anti-ship weapons except for Tomahawk.24 Yet LRASM does little to enhance the Navy’s ability to mass fires from across distributed forces.

LRASM’s potential for mass fires is heavily constrained by platform compatibility because it is not a launch cell compatible weapon. LRASM can only currently be fielded by bombers and carrier aircraft. Despite tests suggesting that LRASM can be fired from launch cells, the Navy continues to describe the program as “a key air launched component of the Navy’s overall Cruise Missile Strategy…”25 In 2021, industry partnered with an Australian firm to refine the development of a surface-launched variant of LRASM that has been termed “LRASM SL,” suggesting that launch cell compatible versions of this weapon are distinct from what the U.S. Navy is procuring for itself.26

A July 2016 test of the LRASM from a MK-41 launcher on the Navy’s Self Defense Test Ship. (Lockheed Martin photo)

Even though LRASM’s range makes it a much less risky missile for air wings to fire at targets compared to Harpoon, these strikes would still tie down a large portion of the air wing to mass enough firepower to be overwhelming. LRASM does not alleviate the need for large volume of fire, which strains the air wing’s ability to cover multiple other roles besides strike. Even with its advanced capabilities, LRASM will not change certain fundamental disadvantages of massing air wings to conduct long-range strikes against warships.

The amount of LRASM inventory is extremely low at about 250 missiles procured for the Navy so far.27 The Air Force’s inventory is even smaller and only numbers slightly less than 100.28 Although the Air Force’s bombers can equip Harpoon missiles, the short range of that weapon and their especially low procurement rate of LRASM may mean the U.S. military’s bombers will have barely any anti-ship firepower to contribute to U.S. sea control for the foreseeable future.

LRASM shares a production line with the much more numerous Joint Air-to-Surface Standoff Missile (JASSM) it is adapted from, and where more than 2,000 JASSM weapons have been procured by the U.S. Air Force so far, and where the Navy has begun to procure the weapon within the past two years.29 The newest forthcoming “extreme range” variants of the JASSM ground-attack missile will feature ranges of up to 1,000 miles, making it one of the first air-launched cruise missiles that can rival the ranges of Tomahawk.30 The JASSM production line is also the most robust of any of the missiles described thus far, with annual production runs numbering in the hundreds as opposed to the other missiles that are only being procured by the dozens.31

August 12, 2015 – A Long Range Anti-Ship Missile (LRASM). (Photo via Wikimedia Commons)
Sept. 13, 2018 – An inert AGM-158A Joint Air-to-Surface Standoff Munition (JASSM) being used in a training exercise on a B-1B Lancer at Al Udeid Air Base, Qatar. (U.S. Air Force photo by Tech. Sgt. Ted Nichols/Released)

The two anti-ship weapons that hold the most promise, LRASM and Maritime Strike Tomahawk, are adaptations of existing munitions that have been produced in far greater numbers – JASSM and the land-attack Tomahawk. Upgrading these existing weapons with anti-ship capabilities and seekers may be a more rapid and cost-effective way to ramp up the anti-ship weapon inventory of the U.S. military compared to building new weapons wholesale. If the forthcoming extended-range variants of JASSM can feature anti-ship capabilities, then the U.S. military will open up a vast array of new options for the distribution and aggregation of firepower between naval and air forces.

Naval Strike Missile – Only Slightly Better Than Harpoon

The Naval Strike Missile (NSM) features a stealthy profile and an advanced seeker, but it brings only a marginal improvement over Harpoon. Similar to Harpoon, NSM has relatively short range at 115 miles and it is not compatible with launch cells.32 It is mainly being fielded by the Navy’s Littoral Combat Ships with only eight weapons per ship, and the Marines are procuring a land-based version. Its short range and launch cell incompatibility make this weapon poorly suited for massing fires from distributed forces. Low procurement rates put the current inventory at slightly more than 110 missiles, hardly enough to make the weapon widely fielded and available for mass fires.33 The main utility of both Harpoon and NSM in a major naval conflict may be relegated to engagements against smaller and more isolated combatants, perhaps in secondary theaters and areas peripheral to larger salvo exchanges.

A Naval Strike Missile in flight. (Photo via U.S. Department of Defense DOT&E)

A Brittle Spear

The ability to mass fires is fundamentally enabled by fielding a large number of long-range missiles across a wide variety of platforms. In terms of numbers, range, and variety, the U.S. military falls woefully short. The U.S. military cannot execute the tactic of distributed massed fires against warships today because it simply does not have the weapons to make it possible. Its current anti-ship missile firepower is extremely concentrated in aircraft carriers and tightly stretched thin everywhere else.

None of the newer U.S. anti-ship missiles will do much to improve the Navy’s ability to distribute and still combine fires, except for Tomahawk. LRASM can somewhat broaden the scope of physical distribution of launch platforms, but it is still a heavily concentrating weapon due to its narrow platform compatibility. LRASM will do little to alleviate the carrier’s heavy burden of shouldering most of the U.S. Navy’s anti-ship capability.

The Maritime Strike Tomahawk strongly stands out as the weapon with the most transformational promise, and it is absolutely fundamental to manifesting DMO. Finally the U.S. Navy will have anti-ship weaponry that is both long-range and compatible with its launch cells, and finally the U.S. military will have more viable anti-ship missile platforms than just carriers. This stands in sharp contrast to great power competitors, who have already broadly distributed anti-ship firepower across their surface fleets, bombers, land-based forces, and submarines.34

A central risk factor is considering what proportion of the overall volume of fire each type of weapon may contribute. Based on these key traits, more risk is incurred the less suitable a weapon is for mass fires. Weapons such as Harpoon or the Naval Strike Missile can certainly add a fraction of the contributing fires, but the more these weapons make up mass fires, the more risk the force will have to assume. 

Click to expand. A table of U.S. anti-ship weapons and key weapon traits for massing fires. (Author graphic)

Among the weapon traits analyzed, the depth of inventory stands out as an especially critical constraint in the capital-intensive nature of modern naval salvo combat. Even if highly capable missiles are being procured, inventory depth is the key variable that will prevent the U.S. military from having enough modern anti-ship missile firepower through at least the rest of this decade. Current stocks of modern U.S. anti-ship missiles are not remotely close to satisfying the demands of a type of combat that can require more than a hundred missiles to overwhelm the defenses of only a few destroyers, where a decade’s worth of weapons procurement can easily be discharged in a matter of hours.

As it currently stands, most of the inventory of the Navy’s anti-ship missiles except for Harpoon could be spent in a handful of salvo engagements. The appropriate amount to meet great power naval threats is not dozens or even hundreds of weapons, but thousands – a figure that grossly exceeds the inventory of all of the U.S. military’s latest generation of anti-ship weapons. And even if procurement rates have substantially grown the inventory 15 years from now, competitors could have grown their own arsenals over the same period, such as by building out deep inventories of anti-ship ballistic missiles and hypersonics that sustain a critical margin of overmatch. 

It is unclear how exactly the U.S. military has chosen to distribute or concentrate its small but growing inventory of modern anti-ship weapons. A major crisis could force the U.S. military to scrounge across the force in a rush to assemble enough weapons to field an adequate volume of fire. If these rare weapons are spread across the east- and west coast-based fleets, the Navy may be forced to engage in an elaborate act of transcontinental crossdecking to concentrate enough credible firepower in crisis response units.

These pervasive capability gaps have created a major window of opportunity for great power challengers to capitalize on the strategic liability posed by the weakness of the American naval arsenal. Until new weapons are fielded in large enough numbers, the U.S. military may be forced to endanger its single most expensive platform to close the gap – aircraft carriers.

Part 3 will focus on assembling massed fires and modern fleet tactics.

Dmitry Filipoff is CIMSEC’s Director of Online Content and Community Manager of its naval professional society, the Flotilla. He is the author of the How the Fleet Forgot to Fight” series and coauthor of Learning to Win: Using Operational Innovation to Regain the Advantage at Sea against China.” Contact him at [email protected].

References 

1. “Tomahawk Cruise Missile,” U.S. Navy Fact File, last updated September 27, 2021, https://www.navy.mil/Resources/Fact-Files/Display-FactFiles/Article/2169229/tomahawk-cruise-missile/.

2. “Flight Operations Support & Line Assistance: Getting to Grips with Fuel Economy,” Airbus, Issue 4, pg. 36-40, October 2004, https://www.smartcockpit.com/docs/Getting_To_Grips_With_Fuel_Economy.pdf.

3. For variable flight profiles of anti-ship missiles, see:

Dr. Carlo Kopp, “Killing the Vampire,” Defence Today, 2008. http://www.ausairpower.net/SP/DT-Vampires-2008.pdf.

Dr. Carlo Kopp, “Evolving Naval Anti-Ship Weapons Threat,” Defence Today, 2010. http://www.ausairpower.net/SP/DT-ASBM-Dec-2009.pdf.

For Tomahawk waypointing capability, see:

“Tomahawk,” Naval Air Systems Command, https://www.navair.navy.mil/product/Tomahawk.

4. Ross R. Hatch, Joseph L. Luber, and James H. Walk, “Fifty Years Of Strike Warfare Research At The Applied Physics Laboratory,” Johns Hopkins APL Technical Digest, Volume 13, Number I, pg. 117, 1992, https://www.jhuapl.edu/Content/techdigest/pdf/V13-N01/13-01-Hatch.pdf.

Kenneth P. Werrell, “The Evolution of the Cruise Missile,” Air University Press, pg. 150, September 1985, https://media.defense.gov/2017/Apr/07/2001728474/-1/-1/0/B_0006_WERRELL_EVOLUTION_CRUISE_MISSILE.PDF.

5. For Harpoon range, see:

Alan Cummings, “A Thousand Splendid Guns: Chinese ASCMs in Competitive Control,” U.S. Naval War College Review, Autumn 2016, https://digital-commons.usnwc.edu/cgi/viewcontent.cgi?referer=https://cimsec.org/?p=37357&preview_id=37357&preview_nonce=33a19394d2&post_format=standard&_thumbnail_id=37675&preview=true&httpsredir=1&article=1143&context=nwc-review.

“RGM-84 Harpoon Block II,” Royal Australian Navy, https://www.navy.gov.au/weapon/rgm-84-harpoon-block-ii.

“Harpoon Next Generation Backgrounder,” Boeing, https://www.boeing.co.kr/resources/ko_KR/Seoul-International/2015/Harpoon-Next-Generation.pdf.

For less common Harpoon Block II+ variant, see:

Kyle Mizokami, “Navy’s Harpoon Missile Misses Target During Test Fire,” Popular Mechanics, July 21, 2016, https://www.popularmechanics.com/military/weapons/news/a21979/navy-shoots-new-anti-ship-missile-misses/

6. “Report to Congress on the Annual Long-Range Plan for Construction of Naval Vessels for Fiscal Year 2023,” Office of the Chief of Naval Operations Deputy Chief of Naval Operations for Warfighting Requirements and Capabilities – OPNAV N9, pg. 9, April 2022, https://media.defense.gov/2022/Apr/20/2002980535/-1/-1/0/PB23%20SHIPBUILDING%20PLAN%2018%20APR%202022%20FINAL.PDF.

7. J. Michael Dahm, “A Survey of Technologies and Capabilities on China’s Military Outposts in the South China Sea,” South China Sea Military Capability Series, Johns Hopkins Applied Physics Laboratory, pg. 6, March 2021, https://apps.dtic.mil/sti/pdfs/AD1128637.pdf.

8. “Weapons Acquisition: Precision Guided Munitions in Inventory, Production, and Development,” General Accounting Office, pg. 14, June 1995, https://www.govinfo.gov/content/pkg/GAOREPORTS-NSIAD-95-95/pdf/GAOREPORTS-NSIAD-95-95.pdf.

9. For capabilities and production history, see:

“Standard Missile 6 (SM-6): December 2021 Selected Acquisition Report (SAR),” Department of the Navy, December 31, 2021, https://www.esd.whs.mil/Portals/54/Documents/FOID/Reading%20Room/Selected_Acquisition_Reports/FY_2021_SARS/22-F-0762_SM6_SAR_2021.pdf.

For weapon range, see:

“Options for Fielding Ground-Launched Long-Range Missiles,” Congressional Budget Office, pg. 24, 2020, https://www.cbo.gov/publication/56143.

10. Sam LaGrone, “SECDEF Carter Confirms Navy Developing Supersonic Anti-Ship Missile for Cruisers, Destroyers,” USNI News, February 9, 2016, https://news.usni.org/2016/02/04/secdef-carter-confirms-navy-developing-supersonic-anti-ship-missile-for-cruisers-destroyers.

11. Mark A. Landis, “Overview of the Fire Control Loop Process for Aegis LEAP Intercept,” Johns Hopkins APL Technical Digest, Volume 22, Number 4, pg. 439-440, 2001, https://www.jhuapl.edu/Content/techdigest/pdf/V22-N04/22-04-Landis.pdf.

12. This calculation was arrived at by dividing the range of the SM-6 (150 miles) using the SM-6’s Mach 3.5 speed (2,685 miles), adding about 30 seconds to account for acceleration to max speed from launch, and a radar horizon profile of a radar mounted 30ft. high and the SM-6 coming into view at about 7,000 feet of altitude, which corresponds to the 150 mile range of the weapon. This comes to about four minutes of warning to the target warship. The subsonic missile time is calculated at 550mph breaking over a horizon that is 20 miles, giving the target warship slightly more than two minutes of warning.

13. “Options for Fielding Ground-Launched Long-Range Missiles,” Congressional Budget Office, pg. 25, 2020, https://www.cbo.gov/publication/56143.

14. “Military and Security Developments Involving the People’s Republic of China 2022,” U.S. Department of Defense, pg. 64-65, 2022, https://media.defense.gov/2022/Nov/29/2003122279/-1/-1/1/2022-MILITARY-AND-SECURITY-DEVELOPMENTS-INVOLVING-THE-PEOPLES-REPUBLIC-OF-CHINA.PDF.

15. “Maritime Security Dialogue: The Aegis Approach with Rear Admiral Tom Druggan,” Center for International and Strategic Studies, November 21, 2021, https://www.csis.org/analysis/maritime-security-dialogue-aegis-approach-rear-admiral-tom-druggan.

16. For total SM-6 inventory figure, see:

“Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 1 of 13 P-1 Line #6, (PDF pg. 137), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

For full-rate production, see:

“Standard Missile-6 (SM-6,” December 2019 Select Acquisition Report, Department of Defense, pg. 7, December 2019, https://www.esd.whs.mil/Portals/54/Documents/FOID/Reading%20Room/Selected_Acquisition_Reports/FY_2019_SARS/20-F-0568_DOC_72_SM-6_SAR_Dec_2019_Full.pdf.

“Raytheon’s SM-6 moves from low-rate to full-rate production Milestone clears path for larger quantities, lower costs,” Raytheon Technologies, May 6, 2015, https://raytheon.mediaroom.com/2015-05-06-Raytheons-SM-6-moves-from-low-rate-to-full-rate-production.

Rich Abott, “Raytheon Wins $1 Billion Contract For SM-6 Full Rate Production,” Defense Daily, December 26, 2019, https://www.defensedaily.com/raytheon-wins-1-billion-contract-sm-6-full-rate-production/navy-usmc/.

17. For 2011-2016 procurement rates, see:

“Department of Defense Fiscal Year (FY) 2017 President’s Budget Submission,” Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 7 of 12 P-1 Line #7 (PDF pg. 137), February 2016, https://www.secnav.navy.mil/fmc/fmb/Documents/17pres/WPN_Book.pdf.

For 2017-2021 procurement rates, see:

Department of Defense Fiscal Year (FY) 2022 Budget Estimates, Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 6 of 11 P-1 Line #6 (PDF pg. 123), https://www.secnav.navy.mil/fmc/fmb/Documents/22pres/WPN_Book.pdf.

18. For 1982 test date: E. H. Corirow, G. K. Smith, A. A. Barboux, “The Joint Cruise Missiles Project: An Acquisition History, Appendixes,” RAND, pg. 46, August 1982, https://www.rand.org/pubs/notes/N1989.html.

19. “Tomahawk Cruise Missile,” U.S. Navy Fact File, last updated September 27, 2021, https://www.navy.mil/Resources/Fact-Files/Display-FactFiles/Article/2169229/tomahawk-cruise-missile/.

20. “Navy awards first ever multi-service contract for Tomahawk Weapons System,” Naval Air Systems Command, May 24, 2022, https://www.navair.navy.mil/news/Navy-awards-first-ever-multi-service-contract-Tomahawk-Weapons-System/Tue-05242022-1347.

21. For 2024 MST IOC, see:

Statement of Frederick J. Stefany, Principal Civilian Deputy, Assistant Secretary of the Navy (Research, Development and Acquisition), Performing the Duties of the Assistant Secretary of the Navy (Research, Development and Acquisition) and Vice Admiral Scott Conn, Deputy Chief of Naval Operations, Warfighting Requirements and Capabilities (OPNAV N9) and Lieutenant General Karsten S. Heckl, Deputy Commandant, Combat Development and Integration, Commanding General, Marine Corps Combat Development Command, before the Subcommittee on Seapower of the Senate Armed Services Committee on Department of the Navy Fiscal Year 2023 Budget Request for Seapower, PDF pages 31-32, April 26, 2022, https://www.armed-services.senate.gov/imo/media/doc/HS_26APR22_RDA_SASC_S_DON_PB23_Shipbuilding_Aviation_Ground_FINAL%20(2).PDF.

For MST low-rate initial production, see:

Department of Defense Fiscal Year (FY) 2022 Budget Estimates, Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 11 of 11 P-1 Line #18 (PDF pg. 269), https://www.secnav.navy.mil/fmc/fmb/Documents/22pres/WPN_Book.pdf.

For current MST production quantity, see:

“Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 3 of 14 P-1 Line #18, (PDF pg. 283), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

22. For plans to recertify all Block IV Tomahawks into Block V variants, see:

“Navy completes first delivery of Block V Tomahawk Missile,” Naval Air Systems Command, March 25, 2021, https://www.navair.navy.mil/news/Navy-completes-first-delivery-Block-V-Tomahawk-Missile/Wed-03242021-1700.

For possibility of 300 Block V recertification kits per year, see:

Department of Defense Fiscal Year (FY) 2022 Budget Estimates, Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 3 of 11 P-1 Line #18 (PDF pg. 261), https://www.secnav.navy.mil/fmc/fmb/Documents/22pres/WPN_Book.pdf.

23. For different Block V subvariants, see:

“Tomahawk Cruise Missile,” Raytheon Missiles and Defense, https://www.raytheonmissilesanddefense.com/what-we-do/naval-warfare/advanced-strike-weapons/tomahawk-cruise-missile.

24. The LRASM range of 350 miles is a rough estimate deduced from the JASSM missile it is derived from, see:

“Options for Fielding Ground-Launched Long-Range Missiles,” Congressional Budget Office, pg. 2, 2020, https://www.cbo.gov/publication/56143.

25. For Navy description of LRASM, see:

“Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 1 of 10 P-1 Line #16, (PDF pg. 261), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

For industry testing of launch cell compatible LRASM, see:

Sam LaGrone, “LRASM Scores in Navy Test Ship Launch,” USNI News, July 20, 2016, https://news.usni.org/2016/07/20/lrasm-scores-ship-launch-test.

26. “Lockheed Martin And Thales Australia Finalize Teaming Agreement To Develop Sovereign Weapons Manufacturing Capabilities In Australia,” Lockheed Martin, April 21, 2021, https://news.lockheedmartin.com/lockheed-martin-and-thales-australia-finalize-teaming-agreement.

27. “Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 7 of 10 P-1 Line #16, (PDF pg. 267), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

28. “Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 1 of 10 P-1 Line #16, (PDF pg. 261), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

29. For JASSM and LRASM commonality, see:

Sandra I. Irin, “Pentagon Accelerates Acquisitions of Ship-Killing Missiles,” National Defense Magazine, December 15, 2016, https://www.nationaldefensemagazine.org/articles/2016/12/15/pentagon-accelerates-acquisitions-of-ship-killing-missiles.

For JASSM inventory: “Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Air Force Justification Book Volume 1 of 1 Missile Procurement, Air Force, Page 4 of 12 P-1 Line #7 (PDF pg. 68), April 2022, https://www.saffm.hq.af.mil/Portals/84/documents/FY23/PROCUREMENT_/FY23%20Air%20Force%20Missile%20Procurement.pdf?ver=QeRLpOSY7vcLmsKbr3C-Qw%3D%3D.

For U.S. Navy first procurement batch of JASSM, see:

Richard R. Burgess, “Navy Plans to Arm F/A-18E/F, F-35C with Air Force’s JASSM-ER Cruise Missile,” Seapower Magazine, June 15, 2021, https://seapowermagazine.org/navy-plans-to-arm-f-a-18e-f-f-35c-with-air-forces-jassm-er-cruise-missile/

30. Brian A. Everstine, “USAF to Start Buying ‘Extreme Range’ JASSMs in 2021, Air & Space Forces Magazine, February 14, 2020, https://www.airandspaceforces.com/usaf-to-start-buying-extreme-range-jassms-in-2021/.

31. “Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Air Force Justification Book Volume 1 of 1 Missile Procurement, Air Force, Page 5 of 12 P-1 Line #7, (PDF pg. 69), April 2022, https://www.saffm.hq.af.mil/Portals/84/documents/FY23/PROCUREMENT_/FY23%20Air%20Force%20Missile%20Procurement.pdf?ver=QeRLpOSY7vcLmsKbr3C-Qw%3D%3D.

32. “NSM™ Naval Strike Missile (NSM),” Kongsberg, https://www.kongsberg.com/kda/what-we-do/defence-and-security/missile-systems/nsm-naval-strike-missile-nsm/.

33. “Department of Defense Fiscal Year (FY) 2023 Budget Estimates,” Navy Justification Book Volume 1 of 1 Weapons Procurement, Navy, Page 1 of 10 P-1 Line #17, (PDF pg. 271), April 2022, https://www.secnav.navy.mil/fmc/fmb/Documents/23pres/WPN_Book.pdf.

34. For Chinese anti-ship weapons and force structure, see:

Dr. Sam Goldsmith, “VAMPIRE VAMPIRE VAMPIRE The PLA’s anti-ship cruise missile threat to Australian and allied naval operations,” Australian Strategic Policy Institute, April 2022, https://ad-aspi.s3.ap-southeast-2.amazonaws.com/2022-04/Vampire%20Vampire%20Vampire_0.pdf?VersionId=tHAbNzJSXJHskd9VppGNRcTFC4hW7UqD.

For Russian anti-ship weapons and force structure, see:

“The Russian Navy: A Historic Transition,” Office of Naval Intelligence, December 2015, https://www.oni.navy.mil/Portals/12/Intel%20agencies/russia/Russia%202015screen.pdf?ver=2015-12-14-082028-313.

Featured Image: PHILIPPINE SEA (Oct. 1, 2019) Independence-variant littoral combat ship USS Gabrielle Giffords (LCS 10) launches a Naval Strike Missile (NSM) during exercise Pacific Griffin. (U.S. Navy Photo by Mass Communication Specialist 3rd Class Josiah J. Kunkle)