Military experts are advocating for a K-nuclear sharing arrangement in which South Korea would acquire and operate nuclear-powered ballistic missile submarines (SSBNs) in coordination with the U.S. This proposal comes amid escalating North Korean nuclear threats and the potential for reactor module transfers from Russia, raising concerns that security on the Korean Peninsula might be deprioritized as global conflicts multiply.
A recent article in the quarterly journal Defense Policy Research from the Korean Institute for Defense Analysis (KIDA), titled, The Potential and Strategic Value of a Korean SSBN-based Nuclear Sharing System, highlights the increasing constraints on U.S. intervention capabilities. As military confrontations erupt on multiple fronts including Taiwan, the Middle East, and Europe, America’s capacity to respond based on strategic priorities is becoming increasingly limited.
The report warns that if the U.S. becomes embroiled in multiple concurrent conflicts, its ability to address crises arising from North Korea’s advancing military capabilities will inevitably diminish. To mitigate potential security gaps, the study emphasizes that South Korea should seek greater autonomy within the U.S.-Republic of Korea (ROK) alliance framework while exploring ways to enhance its contributions to the alliance.
The report proposes establishing a Korean-style nuclear sharing system centered on SSBNs as a key solution. It envisions a unique submarine-based nuclear sharing model in which South Korean SSBNs would patrol between Guam and the East Sea, setting it apart from the North Atlantic Treaty Organization (NATO)-style nuclear sharing method.
Submarines are seen as an effective means to maintain deterrence without directly introducing nuclear weapons into the region, an action that could provoke China and Russia. This approach is also in line with Korean Peninsula denuclearization principles and the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) regulations, thereby preserving the legitimacy of calls for North Korean denuclearization. The study notes that the U.S. is pursuing various security collaborations with allies and partners, partly in response to China’s naval expansion and gaps in its own submarine fleet due to aging vessels.
The report cites a Heritage Foundation study that underscores the need for U.S. cooperation with AUKUS nations to counter China amid shortages in submarine forces. It contextualizes the 2021 U.S. decision to provide Australia with nuclear submarine technology within this framework, further noting that the Heritage report advocated exploring additional nuclear options with South Korea and Japan to counter North Korean threats.
Should South Korea proceed with acquiring SSBNs through consultations with the U.S., the report envisions these vessels—built with American technological assistance—partially replacing retiring U.S. SSBNs in the East Sea and Western Pacific from 2030 onward. These submarines could conduct anti-submarine warfare and intelligence operations against North Korea.
In times of war or heightened tensions, the report argues that SSBNs operating near Guam should be equipped with U.S.-supplied nuclear warheads to bolster deterrence, recommending a minimum fleet of five SSBNs to sustain this capability.
The study concludes by noting that the evolving security landscape, U.S. budget constraints, and potential transactional approaches to alliance management could result in a trade-off between a reduced U.S. troop presence and enhanced nuclear options for South Korea. It stresses the importance of securing shared nuclear storage facilities and maintaining strategic dialogue with the U.S. Given the lengthy development timeline for SSBNs, the report urges immediate action on long-term strategic planning.