All posts by Matthew Gamble

North Korea’s Sea-Based Nuclear Capabilities: An Evolving Threat

North Korea Topic Week

By Matthew W. Gamble


North Korea stunned the world by conducting its first nuclear test in 2006, a mere three years after its withdrawal from the Treaty on the Non-Proliferation of Nuclear Weapons. Despite the small, one-kiloton yield of the device, the test nevertheless signified the rogue state’s entry into the nuclear arena and further complicated the already strategically challenging position on the Korean Peninsula. A recent report by the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies estimated that Pyongyang currently possesses a growing stockpile of between 10-16 nuclear weapons, though the exact number remains unknown. More alarming are the rapid advancements North Korea has recently made in developing nuclear weapon delivery systems, including the recent missile test-launch on May 14th showing considerable progress toward an intercontinental ballistic missile. Considerable resources have been devoted to this pursuit by the famine-stricken state, and investments are beginning to bear fruit. Despite its emphasis on land-based systems such as the new Hwasong-12, North Korea’s evolving sea-based nuclear delivery potential is beginning to pose a considerable threat, lending additional credibility to the Kim regime’s nuclear deterrent.

Nukes at Sea

Of particular concern, North Korea has been making progress toward attaining a nuclear triad by developing a submarine-launched ballistic missile (SLBM) capable of delivering a nuclear warhead. After several failures, the DPRK successfully tested its first SLBM, known as the Pukkuksong-1/KN-11, in late August 2016. With a two-stage solid fuel propellant system, the KN-11 has an estimated range of almost 500 nautical miles, more than enough to threaten major population centers such as Seoul and Tokyo, or military installations like Kadena Airbase in Okinawa, with only limited travel of its launch platform outside of home waters. Notably, it seems the decision was made to opt for a more stable, solid fuel propellant at the expense of range after a series of liquid-fueled missile failures. Not only is a solid fuel propulsion system less volatile, but it enables the missile to be launched on short notice, as it does not require the lengthy and dangerous fueling process required before the launch of a liquid fueled ballistic missile. Currently, the operational status of the KN-11 is unclear, with estimates of service entry varying from late this year to 2020.

In addition to technical advances in SLBM technology, North Korea has made considerable progress in developing a new class of submarine for the Korean People’s Navy (KPN) capable of deploying these weapons. With the first vessel launched in the summer of 2014, the Sinpo-class represents Pyongyang’s first diesel-electric ballistic missile submarine. Similar in size and shape to older Yugoslavian designs like the Heroj-class, the Sinpo-class appears to have incorporated features derived from the Soviet Golf II-class ballistic missile submarine. Indeed, in 1993 North Korean technicians had the opportunity to examine a number of ex-Soviet Pacific Fleet Golf II-class boats before they were scrapped.

When looking at the Sinpo’s ballistic missile launch tubes, the influence of older Soviet designs becomes apparent. In a similar arrangement to the Golf II, a rectangular section of the conning tower houses what appear to be one or two ballistic missile launch tubes. Likewise, given its diesel-electric propulsion system, the Simpo-class shares the Golf-class’ range limitation, estimated to be around 1,500 nautical miles. When paired with the moderate range of the KN-11, the Sinpo-class would require fueling to achieve launch distance of the continental United States. Nevertheless, once made fully operational, these submarines could potentially threaten strategic targets throughout East Asia and could prove difficult to track and eliminate. Moreover, a ballistic missile submarine can launch its SLBMs from a variety of directions, complicating missile defense planning and increasing the vulnerability of potential targets.

Kim Jong Un in the conning tower of what appears to be a Project 633 diesel submarine. (KCNA)

Currently, only one Sinpo-class ballistic missile submarine appears to be active, but additional vessels will likely be completed in the near future. The submarine reportedly suffered damage to its conning tower on 28 November 2015, after a KN-11 failed to successfully eject from its launch tube during a test. Nevertheless, on 24 August 2016, a successful test was conducted where a KN-11 was launched from the vessel. Despite this success, the operational status of North Korea’s SLBM capability remains unclear. Ultimately, the Sinpo-class remains the largest submarine built for the KPN and will represent a significant enhancement of North Korea’s nuclear delivery capacity once perfected, though its small size, limited range, and rudimentary design are substantial shortcomings.

Complicating Deterrence 

The addition of an SLBM, complemented by a workable launch platform, will greatly enhance the survivability of North Korea’s nuclear delivery capacity and improve the credibility of its nuclear deterrent. Currently, North Korea’s land-based nuclear delivery systems rely heavily on fixed infrastructure and operate in the open, which makes them particularly vulnerable to attack. As a result, if Washington were to lose ‘strategic patience’ with the DPRK, Pyongyang would likely see its land-based nuclear forces neutralized in a first strike. Ballistic missile submarines, on the other hand, are more survivable than fixed infrastructure because the vastness and depth of the oceans provide concealment within a wide operational area.

Though the anti-submarine warfare (ASW) capabilities of the combined U.S.-ROK forces are second to none, even a rudimentary submarine such as the Sinpo-class would be difficult to locate and destroy quickly. Consequently, it is plain to see how a ballistic missile submarine would enhance North Korea’s nuclear deterrent. If the DPRK were to ever lose its land-based nuclear delivery systems in a surprise attack, it would still have the ability to retaliate with an SLBM launch against South Korea or Japan. Politically, this would alter the cost-benefit analysis when weighing military action against Pyongyang. Once the nuclear armed Sinpo-class becomes fully operational, it will be even more difficult for the United States to guarantee the complete elimination of all North Korean nuclear delivery systems in a first strike. Under those circumstances, it seems unlikely that South Korea would agree to any preemptive military action against North Korea. Therefore, the scope of action that can realistically be taken against the rogue state is diminished, granting the Kim regime additional political leverage on the international stage. With this in mind, the significance of a fully operational nuclear armed North Korean ballistic missile submarine becomes abundantly clear.

The Range of DPRK Seaborne WMD Threats

Given the range limitations and reliability issues associated with North Korea’s current arsenal of ballistic missiles, the Kim regime may turn to unconventional methods to deliver nuclear weapons to targets well outside the range of its missiles. In the extreme, North Korea could smuggle a nuclear or radiological weapon in a shipping container aboard one of its numerous merchant vessels. A 2005 report by the Congressional Research Service titled, “Terrorist Nuclear Attacks on Seaports: Threat and Response,” highlighted the challenging nature of preventing such an attack. Certainly, North Korea has already demonstrated its willingness and ability to smuggle contraband aboard its merchant vessels undetected.

In 2013, a North Korean-flagged freighter, the Chong Chon Gang, traversed parts of the Pacific undetected after disabling its Automatic Identification System. Eventually, the freighter made it to the Panama Canal where its illicit cargo was discovered after being boarded by Panamanian port authorities. Fortunately, in this case its cargo merely consisted of surface-to-air missile components, disassembled MiG-21s, night-vision goggles, and ammunition. Yet, if the ship was transporting a nuclear or radiological device, the damage that could have been inflicted upon the Panama Canal would have been substantial.

A man looks at a MIG-21 jet found inside a container on the North Korean Chong Chon Gang vessel seized at Manzanillo Port, Panama, on July 21, 2013. Panamanian authorities have found two Soviet-era MiG-21 fighter jets aboard the North Korean ship. (AFP)

For North Korea, smuggling a nuclear device on a freighter would be a high-risk high-reward strategy. A successful smuggling operation followed by a detonation in close proximity to the intended target could serve as the first strike in the opening of a larger war. On the other hand, if the nuclear cargo was intercepted en route to its destination, North Korea would lose the element of surprise and open itself to a retaliatory attack. Although it is unlikely that North Korea would opt to smuggle a nuclear weapon aboard one of its merchant vessels, the threat should not be discounted entirely.


Recent developments in the sea-based nuclear delivery capacity of the KPN have complicated the strategic situation on the Korean Peninsula even further. By diversifying the means by which it can deliver nuclear weapons, the Kim regime has strengthened the credibility of its nuclear deterrence, forcing the U.S. and its allies to think twice before considering military action. Although the North Korean military would eventually succumb to the overwhelming force of American-ROK full-spectrum dominance in a full-scale war, the possibility of nuclear strikes against South Korea and Japan would likely be considered an unacceptable risk by political leaders, thereby taking the option preemptive military action against North Korea off the table. Meanwhile, the threat of nuclear smuggling looms large, adding an additional layer of complexity to the North Korean nuclear problem.

As the DPRK continues to perfect its missile technology, we may one day see Pyongyang with the ability to deliver a nuclear weapon to the continental United States with an intercontinental ballistic missile (ICBM). At this point, whether or not to pursue a strategy of forcible denuclearization is up for debate, but given this turn of events it seems the window of opportunity to do so is closing rapidly.

Matthew Gamble is based in New Brunswick, Canada. His research interests primarily focus on Eurasian geopolitics, capability analysis, and Canadian defence policy. Find him on twitter @Matth_Gamble.

Featured Image: North Korean underwater test-fire of submarine-based ballistic missile. (KCNA/via Reuters)

Rotary-Wing Aviation in the Royal Canadian Navy

By Matthew Gamble

A key part of any modern navy is its rotary-wing component. The capabilities that helicopters bring to naval operations are essential in the context of modern warfare, and many large navies around the world boast impressive fleets of shipborne rotary-wing aircraft. Smaller navies, however, need to make due with much less, and there is perhaps no better example of a small navy employing its limited rotary-wing assets to the fullest extent as the Royal Canadian Navy (RCN).

Serving with the RCN for over 50 years, the Sikorsky CH-124 Sea King has been the backbone of the navy’s deck based rotary-wing aviation. Based on the American-designed Sikorsky SH-3, the CH-124 was introduced in 1963 to augment the anti-submarine warfare (ASW) abilities of RCN vessels in response to the growing threat of increasingly capable Soviet nuclear submarines. Since then, the aircraft has proven its versatility by filling capability gaps in the sometimes cash-strapped Royal Canadian Navy by conducting search and rescue operations, disaster relief missions, and even patrols to monitor water pollution. Given the smaller size of Canadian naval vassals, the RCN found the Sea King’s fold-up rotor and tail to be particularly useful as this allowed the aircraft to be carried on the Iroquois-class destroyers and Halifax-class frigates. Likewise, the aircraft’s amphibious hull proved to be popular among its pilots, as it enabled the aircraft to conduct emergency “waterbird landings” if the need arises. Overall the Sea King became a jack-of-all-trades for the RCN, with the aircraft being one of the busiest in the whole of the Canadian Forces.

IS2005-2137a 31 July, 2005 Persian Gulf (Arabian Gulf) region Crewmembers from HMCS Winnipeg's helicopter detachment prepare a CH-124 Sea King for flight operations in the Gulf of Oman. The Canadian frigate is part of Operation ALTAIR, Canada's maritime contibution to the U.S.-led coalition campaign against terrorism mission known as Operation ENDURING FREEDOM. Photo: Sgt Frank Hudec, Canadian Forces Combat Camera Le 31 juillet 2005 Région Arabo-Persique Des membres de l’équipage du détachement d’hélicoptères du NCSM Winnipeg préparent un hélicoptère dans le but de participer à des opérations aériennes dans le golfe d’Oman. La frégate canadienne participe à l’opération Altair, la contribution maritime du Canada à la campagne dirigée par les É. U., menée par la coalition contre le terrorisme et connue sous le nom d’opération Enduring Freedom. Photo : Sgt Frank Hudec, Caméra de combat des Forces canadiennes. Image size = 9.86" x 5.34" 300 DPI 2960 x 1604 pixels
31 July, 2005 Persian Gulf (Arabian Gulf) region Crewmembers from HMCS Winnipeg’s helicopter detachment prepare a CH-124 Sea King for flight operations in the Gulf of Oman. (Photo: Sgt Frank Hudec, Canadian Forces Combat Camera)

Landing the Sea King on the deck of a small vessel in rough seas, however, still proved to be a significant challenge for the RCN. Nonetheless, an ingenious solution was devised in the early 1960’s by Canadian pilots of Experimental Squadron 10 (VX 10) based in Shearwater, Nova Scotia, with assistance from Fairey Aviation. What they developed was the world’s first Helicopter Hauldown and Rapid Securing Device (HHRSD), sometimes referred to as “beartrap.” To employ the retrieval device, a probe-tipped cable is lowered from the Sea King to the deck of the vessel upon which the aircraft is attempting to land. The ship’s crew then attaches the probe to a heavier cable and runs the assembly through the HHRSD. The cable is then winched back up and attached to the helicopter. Once secure, the pilot increases power and the cable synchronizes the helicopter’s movements with those of the ship. The pilot gradually decreases power and the frame of the beartrap steadily ‘reels in’ the helicopter until it touches down safely on the deck. In essence, the beartrap has allowed the RCN to conduct flight operations under even the most hostile weather conditions, and Sea Kings gained a respected reputation for continuing to fly during exercises and on joint-operations even when other NATO allies had suspended flight operations. To this day the beartrap stands as a significant Canadian contribution to deck-based rotary-wing operations, and the device was subsequently adopted by various navies around the world.

ASE Systems Off Helo Hauldown Landing of CH-124 Sea King aboard HMCS Charlottetown in July 2012 during OP ARTEMIS in the Gulf of Oman. (Steve Barnes via Youtube)

By 1986, the Canadian Department of National Defence (DND) began to seek a replacement for the now aging Sea Kings. Problems with the aircraft’s transmission raised concerns about its safety and continued viability among DND staff in Ottawa. Nevertheless, the aging Sea Kings remained in service and were even pressed into action in the Persian Gulf in 1990. Shortly after this successful deployment, the Canadian Progressive Conservative government led by Prime Minister Brian Mulroney signed a $4.4-billion-dollar contract with European Helicopter to replace the aging Sea Kings with a version of the AgustaWestland AW101 to be designated the CH-149 Cormorant in Canadian service. However, a year later, the newly elected Liberal government led by Jean Chretien cancelled the order and only a few Cormorants were accepted into service. It would be another ten years before the Liberal government would sign a contract procuring a new helicopter for deck-based operations. 

Following a competition to find a suitable replacement for the Sea King held by the DND in 2004, the Sikorsky H-92 Superhawk emerged victorious. Shortly thereafter, the Canadian Government announced plans to acquire 28 new Superhawks under the designation CH-148 Cyclone. The price tag of the deal was a whopping $1.8 billion, a very significant sum for a Canadian defence expenditure. Deliveries were scheduled to start in 2009, but repeated delays due to development problems with the aircraft pushed the initial delivery of six helicopters back to June 2015. These delays caused significant political fallout as a number of government ministers publically criticized the program because of the setbacks. Nevertheless, the Canadian Government announced it was moving forward with the deal. Currently, a total of nine Cyclones have been delivered, finally allowing for the gradual retirement of the long-serving Sea Kings.

Although it lacks the amphibious capability of the Sea King, the Cyclone’s performance characteristics are vastly superior, and the new aircraft will greatly enhance the rotary-wing capabilities of RCN vessels. In addition to the latest avionics, the Cyclone is equipped with Integrated Mission and Sonobuoy Acoustic Processing Systems developed by General Dynamics Canada. Furthermore, the helicopter’s armament consists of two Mark-46 Mod V torpedoes mounted on BRU14 electro-mechanical ejector racks and door-mounted machine guns. The Cyclone’s airframe also incorporates protection from both lightning strikes and high-intensity radio frequency pulses. These characteristics make the CH-148 a very capable machine comparable to other modern deck-based rotorcrafts, such as the Eurocopter Panther and the NHIndustries NH90 NFH.

HS28-2016-0001-011 One of Canada's newly acquired CH-148 Cyclone helicopters practices landing procedures on HMCS Halifax off the coast of Nova Scotia on 27 January 2016. Photo: Ordinary Seaman Raymond Kwan, Formation Imaging Services, Halifax. HS28-2016-0001-011 Le nouvel hŽlicoptre CH-148 Cyclone, acquis rŽcemment par le Canada, pratique des manÏuvres dÕatterrissages sur le Navire canadien de Sa MajestŽ (NCSM) Halifax prs des c™tes de la Nouvelle ƒcosse le 27 janvier 2016. Photo : Matelot de 3e classe Raymond Kwan, Services dÕimagerie de la formation, Halifax.
One of Canada’s newly acquired CH-148 Cyclone helicopters practices landing procedures on HMCS Halifax off the coast of Nova Scotia on 27 January 2016.(Photo: Ordinary Seaman Raymond Kwan, Formation Imaging Services, Halifax)

In the future, rotary-wing aircraft stationed on Canadian vessels will face a variety of challenges. Chief among these is the evolving threat posed by increasingly sophisticated Chinese submarines. Therefore, the ASW capabilities of the Cyclone could ultimately prove indispensable to the RCN in future operations, especially in contested waters or in Canada’s vulnerable Pacific littoral areas. Similarly, as Canada pivots to take a more active role in the Arctic, the Cyclone will play a key role in that theater of operations as a countermeasure to the potential threat posed by surface or undersea incursions. In addition, the RCN is also increasingly called upon to assist in disaster relief operations where reliable helicopters often prove to be highly valuable. The Cyclone will certainly be called upon for search and rescue, as well as tactical transport.

Perhaps the greatest test the new helicopter will face will be to operate effectively in a low budget environment.Nevertheless, the Cyclone’s introduction into service signals a new era of enhanced safety and capabilities for rotary-wing operations in the Royal Canadian Navy, and the new aircraft will undoubtedly form the mainstay of this vital component for many years to come.

Matthew Gamble is an International Relations student at St. Thomas University, Fredericton, New Brunswick, Canada. His interests primarily focus on the foreign policy of Eurasian states, and new developments in warfighting capability.