Tag Archives: Pacific

The Geometry of War at Sea: The Leyte Gulf Example

LCDR Daniel T. Murphy, U.S. Navy


General MacArthur’s operational idea, eventually embraced by Admiral Nimitz, President Roosevelt, and the Joint Chiefs, was to retake the Philippines as an intermediate base of operations from which to launch air strikes against Formosa, and eventually the Japanese home islands. Leyte was selected as the initial entry point to the Philippines because it had an “excellent anchorage” and was a location from which land-based bombers could reach all parts of the Philippines, the coast of China, and Formosa.1

The Japanese Imperial General Headquarters had a strong feeling that the two prongs of the American offensive would converge on the Philippines in what Milan Vego would describe as a penetration maneuver, where the attacker seeks to break up or penetrate a selected sector of the defender’s main line of position and move into his rear area.2  Japan’s most critical Sea Lanes of Communication (SLOC) to the southern resource area ran through the Philippines. The Luzon Strait was an especially important SLOC. According to Donald Chisolm, the southern resource area provided 75 percent of the world’s rubber, 66 percent of the world’s tin, and had initially given Japan self-sufficiency in petroleum.  U.S. anti-shipping activities through 1944 had already reduced Japan’s oil supply to a trickle. Losing the Philippines would run the well dry.3

When U.S. forces landed in Leyte, Japan had prepared a quick counterattack in the hope of forcing the Mahanian battle they had sought since Midway. To destroy the U.S. fleet and retain the Philippines, Japan’s SHO-1 plan involved a double envelopment maneuver that required careful synchronization between diversionary and attacking forces.

Lines of Operation

For the invasion of Leyte, U.S. forces had one principal line of operation and two ancillary lines. The principal line was the landing on the western shore of Leyte, under the operational control of MacArthur. This principal line included land, sea and air components. The Seventh Fleet naval component, under Admiral Kinkaid, included a Northern TF 78 under Rear Admiral Barbey which landed at Tacloban and a Southern TF 89 under Vice Admiral Wilkinson which landed at Dulag.

Prior to the initiation of the principal line of operation, the first ancillary line was initiated by Vice Admiral Halsey’s Fast Carrier TF 38. TF 38, which included carrier groups TG 38.1, 38.2, 38.3 and 38.4, attacked Japanese air bases in Okinawa, Luzon, and Formosa. By destroying more than 500 aircraft and reducing Japan’s cadre of newly trained pilots, this initial ancillary line of operation reduced Japan’s air capacity to challenge the U.S. movement into Leyte.

A second ancillary line was the protection of the landing operation. This ancillary line had two operational commanders. Admiral Kinkaid had tactical control of multiple Seventh Fleet components, including the Fire Support Group TG 77.2, the Close Covering Group TG 77.3, the Escort Carrier Group TG 77.4 under Rear Admiral Sprague (which included the carriers assigned to Taffy 1, 2, 3 and 4), and the PT boat squadrons assigned to TG 70.1. Also providing protection to the landing operation was Halsey’s Fast Carrier TF 38, over which MacArthur did not have operational control. TF38 transitioned from the first ancillary line to this second ancillary line after the initial landings were completed. Halsey reported directly to Nimitz at CINCPAC and had a supporting relationship with MacArthur and Kinkaid.  Arguably, the lack of unified command over this secondary but critical line is one of the reasons that the Leyte operation was put at risk when Halsey uncovered the San Bernardino Strait to pursue the Japanese Northern force.

Approach of Naval Forces in the lead up to the Battle of Leyte Gulf (Via history.army.mil)

The deployment of the U.S. submarines DARTER and DACE to intercept and reduce Kurita’s Center Force as it approached the operating area may be considered a third ancillary line, especially since the subs were strategic assets that remained under CINCPAC control. 

To counterattack against the U.S. invasion, Japan had one principal and one ancillary line of operation.  According to Vego, Japan’s principal line of operation was the Center Force under Vice Admiral Kurita that intended to penetrate the San Bernardino Strait and attack U.S. landing forces at Tacloban. Vego said the Southern Force under Vice Admirals Shima and Nishimura that intended to transit Surigao and attack the U.S. landing force from the south was an ancillary line.4  One could argue that the Center and Southern forces were either: (a) two pincer components of one principal line of operation; or (b) two separate principal lines. The diversionary Northern force under Vice Admiral Ozawa was the ancillary line intended to divert the U.S. fast carrier task forces to the north, so that they could not threaten the Center and Southern Forces.

As the battle evolved, Japanese lines of operation remained static. However, U.S. lines shifted between 24-25 October. Halsey created a new line of operation when he transitioned TF 38 from a covering force to an offensive force focused on Ozawa’s Northern force.  Admiral Kinkaid created two new lines of operation when he detached Rear Admiral Oldendorf to guard Surigao Strait with his battleships, cruisers, destroyers, and PT boats against the Southern Force, and Rear Admiral Sprague to defend against Center Force which came through San Bernardino.

Basing Structure and Impact on Operations

Per Vego’s definition, a base of operations should provide multiple short lines of operations.5 Before Leyte, Japan occupied what Vego called a “central position with respect to the adjacent Asian landmass and any hostile force approaching from across the Pacific.”6 Compared to the U.S., Japan had multiple relatively short interior lines of communication. The Japanese home islands were the main base, and Luzon was an intermediate base.

However, as explained by Chisolm, Japan’s combined interior lines totaled more than 18,000 nautical miles and the Luzon Strait was a significant choke point in that network. The Japanese had not built sufficient submarines or destroyers to protect those lines and they had not built sufficient shipping capacity to make up for losses due to U.S. anti-shipping efforts.7 So, although Japan had a base of operations with multiple short interior lines, the U.S. found the weak points in that base early in the war and attacked it with the submarine force. Then, in the campaigns leading up to the Leyte operation, U.S. forces eliminated several of Japan’s fleet oilers. As a result, after the Battle of the Philippine Sea, Japanese carriers returned to home waters where they could be protected by land-based aircraft and continue to train pilots. Japan’s other large combatants moved to Lingga Roads (Singapore), where they had access to oil, but less access to ammunition and less ability to operate with the carriers.

Thus, in the summer of 1944, the Japanese basing structure was already significantly weakened. If the U.S. was able to dislodge Japan from their intermediate base in Luzon, they would essentially turn Japan’s network of interior lines into a network of exterior lines, vulnerable not only to continued submarine attack, but also to land-based air attack.

Japanese shipping routes destroyed during the Leyte Operation. (Via history.army.mil)

In comparison, the U.S. occupied what Vego calls an exterior position in the theater. The U.S. mainland was the main base of operations, and Hawaii was an intermediate base. As explained by Chisolm, the U.S.’s exterior lines into the South Pacific were extremely long – more than six thousand miles from the U.S. mainland, and more than two thousand miles from Australia.8 However, the U.S. exterior lines were not as vulnerable as the Japanese interior lines. While the Japanese fleet was suffering from attrition, the U.S. fleet was expanding, and each month was able to increase the number of escort resources dedicated to the protection of shipping. And while Japan’s link to their southern resource area was becoming increasingly tenuous, CONUS-based war production was hardly resource-constrained.

Decisive Points in the Operation

Vego defines a decisive point as a geographic location or source of military or non-military power to be targeted for destruction or neutralization.9 As Vego suggests, the San Bernardino and Surigao Straits were decisive points for the Japanese heavy surface forces in their intended advance to Leyte Gulf.10 However, for Japan, the most decisive point in the operation was in the Leyte Gulf itself, where the U.S. landing force would be vulnerable and where the Seventh and Third fleets would be protecting the landings. It was there that Admiral Toyoda planned for his pincers to join in a combined action against the U.S. fleet, ideally with a Mahanian ending.

In contrast, prior to Japan’s counter attack, U.S. forces focused on two decisive points: the northern and southern landing zones on the west coast of Leyte. When Japanese forces counter-attacked, the U.S. changed focus and saw the two straits, San Bernardino and Surigao, as the most decisive points. As a result, Admiral Kinkaid massed the firepower of his surface fleet in the Surigao Strait and expected the airpower of Halsey’s TF 38 to cover San Bernardino. 


MacArthur’s operational idea of capturing the Philippines to create an intermediate base of operations for air strikes against Formosa and the Japanese home islands worked. Seven years after Leyte, Nimitz said “from hindsight . . . I think that decision was correct.”11  In summary, U.S. lines of operation were more flexible and less interdependent than the Japanese lines of operation. Ironically, the external U.S. basing structure, when looked at holistically, had greater durability than the internal Japanese basing structure. Also, the U.S. more effectively concentrated kinetic effects on specific decisive points in the geography, and specifically in the Surigao Strait. U.S. forces ultimately won at Leyte because they better exploited the geometry of the operating area.  

Daniel T. Murphy is a Lieutenant Commander in the U.S. Navy, currently serving in the Office of Naval Intelligence. In his civilian career, he is a full-time professor at Massachusetts Maritime Academy, and an adjunct faculty member at Northeastern University. Lieutenant Commander Murphy earned his bachelor’s degree from the University of Massachusetts, and master’s degrees from Georgetown University and from the National Intelligence University. 

The views expressed in this paper are those of the author and do not reflect the official policy or position of the Department of Defense, the U.S. Navy, or the U.S. Government.


[1] M. Hamlin Cannon, Leyte: The Return to the Philippines, Washington: Center for Military History, 1993), 3.

[2] Milan Vego, Joint Operational Warfare: Theory and Practice, (Newport: U.S. Naval War College, 2009), VII-54.

[3] Donald Chisolm, Leyte Gulf: The Strategic Background (NWC lecture), U.S. Naval War College, 2009.

[4] Vego, IV-64.

[5] Vego, IV-56.

[6] Vego, IV-53.

[7] Chisolm (NWC lecture).

[8] Chisolm.

[9] Vego, IV-60.

[10] Vego, IV-61.

[11] Samuel Eliot Morison, Leyte: June 1944-January 1945, (Annapolis: Naval Institute Press, 1958) 10.

Featured Image: The crew of the Japanese aircraft carrier Zuikaku salute as the flag is lowered during the battle off Cape Engaño, October 25, 1944. (Wikimedia Commons)

A Post-It Rebel Goes to Sea

This article originally appeared on Medium and was republished with the author’s permission. You can read it in its original form here

By Anne Gibbon

Design thinking is beloved by many, and is more than a flash in the long list of new management tools. Why? Because it’s embodied learning. In recruiting your body, emotions, and rational brain to explore problems with others, we get to better solutions than pondering them alone in a cubicle. But for messy problems and large bureaucracies, design thinking alone isn’t sufficient. Systems dynamics appears to be the discipline of choice, but up to this point, the theoretical underpinnings have been developed to the exclusivity of embodied exercises.

This is my story of learning to facilitate design thinking as an embodied experience, rather than an intellectual exercise, and to begin to include systems thinking into the work. I have faith that the small prototypes will eventually snowball and make a greater impact than well written policy think pieces alone.

I confess, I put bandaids over my piercings. I never should have done that, I should have just taken them out — but the piercings are more me than the uniform these days.

Thirteen months after finishing ten years of service in the Navy, and days after finishing a fellowship at Stanford’s Design School, I put my foot down and really stretched my rebel wings. I got a very small nose piercing and three studs in one ear, most people don’t even notice them. But to me they are freedom. My problem: I still had to show up at Navy Reserve drill weekends with a proper uniform on. Too bad I never did ‘uniform inspection’ very well. One weekend someone complained about my pink nail polish and the gold ball earrings that were 2mm too big; I think she would have fallen out of her chair if she had discovered the band aids weren’t covering scratches.

The author leads a workshop at the Silicon Valley Innovation Academy in July 2015
The author leads a workshop at the Silicon Valley Innovation Academy in July 2015

For the last two years of running design thinking workshops for various ranks and departments of the military, I have done the equivalent of putting band aids on piercings. We used Post-It notes and sharpies, but I usually left the improv at home. And the effect was an often neutered process. I led the groups through exercises and talked about modes of thinking — deductive, abductive, and inductive — as a way to make the creative, messy work more palatable to people who spent lives in frameworks so narrowly defined that playing at charades with their colleagues would have represented an existential crisis.

November 2013, our d.school fellows group hard at work

Design thinking has been the bright shiny magic wand that somehow hasn’t lost its luster. HBR gave it some east coast gravitas by featuring the process on the cover of their September issue. Popular in many management and product design circles, design thinking continues to spread. The White House just published a post about the use of Human Centered Design (HCD) by the USDA and the Office of Personnel Management’s Innovation Lab to improve the National School Lunch Program. My parents are still confused that I make a living writing on post its, but I feel lucky to be one of the many professionals using this process and adapting it for the real world. Fred Collopy, a professor of design and innovation at Case Western University has spent a career immersed in the theories of decision science, systems thinking, and design. He makes the point that design thinking has been so successful as a practical tool to effect change in organizations precisely because practitioners engage with it first by doing — not by thinking through the associated theories. Fred makes the point that systems thinking failed to spread widely as a management tool, not because it isn’t applicable, but because the discipline didn’t make the leap from theory to embodied exercises. The arcane details of the theories were and are hotly debated by a few, with the result being that the practical exercise of the main concepts are lost to the rest.

In large part, design thinking has avoided this trap because some of the most successful schools teaching the process are schools of practice, not ivory towers of thought. While I personally love dissecting the minutiae of different modes of thinking, the advances in neuroscience that allow us to explore augmented sensing, and the role that the autonomic nervous system plays in reaching creative insight, I reserve that for my fellow design practitioners. I’ve learned that when I’m leading a workshop, my job is to be the chief risk taker for the group, the leader in vulnerability. Their job is to embody each step in the process, and by fully immersing themselves, stumble into surprising reframes, 1000 ideas for a solution, and a few brilliant, wobbly prototypes.

While Fred’s article describes design thinking more as an evolution to systems thinking, I see them as complementary disciplines. Systems dynamics is worth plumbing intellectually, but for the purpose of emerging on the other side with methods and exercises that can be used as tools in the world, similar to the 5 step design thinking process from Stanford’s dschool. The complex theories associated with systems thinking and systems dynamics have at their root a set of ideas very similar to design thinking — engaging a broad set of stakeholders, using scenarios to explore them, reframing problems, and iterating. I want to explore what they might do together, with both disciplines having a rich underpinning of theory and accessible, embodied exercises.

Over a period of about seven months this year, I consulted (civilian role, not reservist) for the Pacific Fleet. I worked for a staff function in Pearl Harbor, Hawaii, and got the best of both worlds — the camaraderie that is a unique joy known to those who have served, and the luxury of wearing hot pink jeans to work. I learned a lot about myself as a designer and a facilitator. At the end of those months, I wrote a long report on how design thinking and systems dynamics might serve the vision of the Pacific Fleet commander, Admiral Swift. The staff that hired me didn’t ask for any insights on systems dynamics, but I gave it to them anyways.

Natural Resources in the South China Sea, Courtesy CSIS Asia Maritime Transparency Initiative http://amti.csis.org/atlas/

The Pacific Fleet needs uniformed practitioners of design thinking and systems dynamics who understand the theoretical nuances and who can also lead the embodiment of the exercises. They need this because the messy military problem they concern themselves with — maritime security — can’t be silo’ed into the pieces that only relate to the military, leaving other aspects to diplomats and environmentalists. Maritime security in our era is about rapidly declining natural resources, extreme climate events, rising levels of violence at sea, but more importantly, these different forces affecting maritime security are so interconnected that they require intense collaboration with unexpected partners. I fear that if we frame the problem of maritime security as an issue between great powers best left to great navies, we will miss the dynamics influencing the global system that supports human flourishing — our food, our climate, and many people’s freedom. (Did you know about the extent of slavery at sea?)

 Global Fishing Watch, the prototype from Google, Oceana and SkyTruth to use open source satellite data to identify illegal fishing.
Global Fishing Watch, the prototype from Google, Oceana and SkyTruth to use open source satellite data to identify illegal fishing.

I don’t have a suggestion for how to frame the problem of human flourishing and maritime security in the Pacific and Indian Oceans. I have my own opinions, but I would rather they be challenged and iterated on through a process that mixes systems and design thinking. How should the Pacific Fleet approach the challenge of understanding and leveraging the system of maritime security in Indo-Asia? Instead of policy, I suggest behaviors I think Admiral Swift would want to observe as patterns in his Fleet.

  • Encouraged collaboration — Leaders emerge from the crowd, assume the role of creative facilitator, and ensure collaboration when it’s needed.
  • Innovation at sea — Sailors innovating ‘just in time’ on deployment lead to non-traditional employment of fielded capability.
  • Using patterns — Sailors provide context, not single data points. Leaders guide the mastery of knowledge and foment the curiosity to identify and exploit patterns of action.
  • Decentralized Execution — Leaders prepare subordinates to be decision-makers, challenging them to gain insights on context and patterns.
  • The crowd organizes itself — Communities of interest will proliferate, building networks between the silos of the operational, maintenance, and R&D force.
  • The crowd learns together — The Fleet leads the debate of war fighting instructions and populates a shared electronic repository of FAQ’s and how-to resources.

My contract ended with the Pacific Fleet at the end of July, and in keeping with my commitment to spread my wings, I’m leaving for New Zealand to work and play with food and agriculture technology and innovation ecosystems. But first, my own embodied prototype of decentralized execution. On October 26 and 27, a couple friends, a senior officer at the Department of State and a PhD futurist, and I will co-facilitate a design workshop in San Francisco on maritime security. We’re inviting a wildly diverse group of participants and we’re going to test new methods for embodied systems thinking. There’s no contract guaranteeing pay and no senior leader who has promised to take the prototypes from the workshop and shepherd them to execution.

Which means there are no rules on this adventure. We’ll publish the exercises mixing systems dynamics and design thinking, and we’ll share the prototypes — hopefully you’ll test them. Please get in touch if you’re interested in more detail.

Sea Control 96 – Host Review

seacontrol2Our cadre of hosts: Matthew Hipple, Natalie Sahmbi, Alex Clarke – and now Matthew Merighi, discuss everything – from China to personal life. This is an update or sorts, or an introduction, for those who haven’t been with us from the beginning, or those who want to know what comes next.

DOWNLOAD: Host Update

Sea Control 90 – An Australian Marine Corps?

seacontrol2Should Australia develop its own Marine Corps?

In this podcast, Natalie Sambhi interviews Peter Dean, Senior Fellow at ANU’s Strategic and Defence Studies Centre, and Associate Dean Education at the ANU’s Coral Bell School of Asia Pacific Affairs, on the development of Australia’s amphibious capability. Why is Australia developing an amphibious capability? Where would it deploy this force? Also in this episode, they discuss what amphibious capability enables Australia to do with partners like the US, and Peter shares his strong sentiment on whether LHDs could be used as mini aircraft carriers.

For more on this topic, check out Peter’s recently co-authored report with PACOM’s Lieutenant Colonel Ken Gleiman, Beyond 2017: the Australian Defence Force and amphibious warfare.

DOWNLOAD: Australian Marine Corps?

Music: Sam LaGrone

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