North and South Korea Race to Develop Nuclear Submarines
Tensions in East Asia are escalating as North and South Korea ramp up their efforts to develop nuclear-powered submarines. This arms race has intensified in light of recent shifts in the United States’ security strategy in the region. On November 2, 2023, North Korean state media unveiled an image of what it described as an “8,700-ton nuclear-powered strategic guided missile submarine.” This announcement marks the first time North Korea has disclosed the tonnage and the almost completed hull of the submarine since it declared its ambitions for nuclear submarines in 2021.
North Korean leader Kim Jong Un stated that this new vessel is crucial for defending the country against what he called “the negative security situation that has come as present reality.” In his remarks, Kim criticized South Korea’s plans to develop its own nuclear submarines, labeling them as “an offensive act… that must be countered.”
In response, South Korea is moving swiftly to build its own nuclear submarines. Following the approval from former President Donald Trump in October 2023, a pan-government task force was established last week in Seoul. Wi Sung-lac, South Korea’s national security adviser, indicated that the country is negotiating with the U.S. for access to military-use nuclear fuel. This development aligns with the U.S. objective of encouraging its allies to enhance their defense capabilities.
South Korea has long sought to establish nuclear submarines as a counter to North Korea’s increasing nuclear threats, which have expanded to include maritime capabilities in recent years. In addition to its submarine program, North Korea has tested submarine-launched nuclear missiles and claims to have developed a nuclear-capable torpedo.
Ahn Gyu-back, South Korea’s defense minister, emphasized in October that conventional, diesel-powered submarines “can’t compete with nuclear subs North Korea is building in underwater endurance and speed.”
Strategic Implications for the Region
The U.S. anticipates that South Korean nuclear submarines will serve a broader purpose beyond countering North Korea. During a visit to Seoul in November 2023, Admiral Daryl Caudle, the chief of naval operations of the U.S. Navy, expressed expectations that these submarines would contribute to addressing combined regional threats, particularly from China.
President Lee Jae Myung acknowledged this perspective during his October summit with Trump, mentioning the limitations of diesel submarines in tracking vessels in both North Korean and Chinese waters. Retired South Korean navy captain Yoon Sukjoon noted that it is “a given” that South Korean nuclear submarines will operate beyond the Korean Peninsula, potentially contributing to strategic deterrence against the Chinese Navy in the Indo-Pacific region.
Yet, South Korea maintains a cautious approach regarding military confrontation with China, its largest trading partner. Lee’s administration clarified that his comments referred to submarines operating in proximity to North Korea and China, rather than implying any direct military engagement with Chinese vessels. This position reflects a wider sentiment among South Koreans, with a recent survey indicating that many prefer the country to remain neutral in the event of conflict between the U.S. and China.
Growing Concerns and Public Sentiment
The increasing focus on nuclear capabilities is not limited to South Korea. Japan has also indicated its willingness to develop nuclear-powered submarines. As China’s influence expands, both nations are wary of being drawn into its sphere of control. Kim Heungkyu, a political scientist at Ajou University, noted that as the U.S. shifts its defense focus, allies in Asia are becoming increasingly distrustful of its commitment to regional security.
A poll conducted by the private think tank Asan Institute in March revealed that less than half of South Koreans believe the U.S. would respond with nuclear weapons if North Korea were to attack the South. Conversely, a majority of South Koreans support developing nuclear capabilities, even at the risk of international sanctions or the withdrawal of U.S. troops from the region.
Kim argues that in a potential new international order without significant U.S. presence in the Western Pacific, South Korea must formulate a survival strategy that includes nuclear weapons. He asserts that nuclear-powered submarines could serve as an “entry point toward a much bigger goal” of nuclear armament.
While the South Korean government, which is in talks with the U.S. about uranium enrichment and reprocessing spent fuel, has denied aspirations for a nuclear arsenal, analysts like Kim contend that the current U.S. administration is inadvertently steering South Korea and Japan toward nuclear armament.
With the stakes rising in Northeast Asia, the implications of these developments will be significant not just for the Korean Peninsula but for the broader regional security landscape.
