Analysts predict potential escalation of nuclear submarine programs in China and Japan despite Seoul’s strategic need.
President Donald Trump’s announcement that he is approving South Korea to build nuclear-powered submarines in the United States marks a success for Seoul’s three-decade effort to acquire nuclear submarines, according to experts.
However, experts also warned that the move will have geopolitical ramifications, including the possibility that China or Japan could accelerate their own nuclear sub programs in return. The project faces significant hurdles, given the logistics and cost of building nuclear submarines and the lack of clarity around Trump’s statement.
Seoul’s Decades-Long Pursuit Achieves Breakthrough
Trump’s announcement via his Truth Social account comes after South Korean officials have lobbied US administrations for around 30 years to allow the key ally to develop its own nuclear submarines, said Kim Min-seok, a Research Fellow at the Korea Defense and Security Forum. Only two other countries, the United Kingdom and Australia, have gained access to America’s highly sought-after nuclear sub technology.
Collin Koh, a senior fellow at Singapore’s S. Rajaratnam School of International Studies, noted that the changing strategic environment, particularly North Korea’s announcement of its own nuclear-powered submarine program and proven Submarine-Launched Ballistic Missile program, justified Seoul’s need for submarines that can stay underwater longer to track these threats.
Regional Instability Concerns
Robert York, the director for regional affairs at the Pacific Forum in Honolulu, cautioned that the decision is unlikely to sit well with South Korea’s other neighbors, particularly China and Japan. Jenny Town, a Korean expert at the Stimson Center, echoed this sentiment, stating on X that „Nothing good” will come from the announcement in regional terms, adding, „This certainly isn’t going to increase stability in the region, that’s for sure.”
York suggested that Tokyo is likely to avoid publicly airing grievances to present a unified strategic front with the US and South Korea but that the move may push Japan further down the path of pursuing nuclear-powered subs. Koh noted the Japanese public’s concerns about nuclear power may cause domestic political headwinds.
China, however, is unlikely to show such restraint. York said that Beijing „will probably use official and unofficial channels to portray this as more dangerous instigation by the US.”
Koh predicted China will also push ahead with its own nuclear submarine program, stating, „China already has a functional nuclear submarine program and Seoul’s decision to develop its own nuke boats will only serve as another strategic justification for it to push on with this area of investment.”
Building Blocks Or Stumbling Blocks? Unclear Program Structure Raises Questions
The specific details of South Korea’s nuclear submarine program and potential technology transfers remain unclear.
Jon Wolfsthal, a former special assistant on nuclear issues to President Barack Obama, stated that the deal’s structure will determine if US Congressional involvement is required. He explained that under the existing nuclear power agreement between the US and South Korea, transferring nuclear material to Seoul requires a 90-day review in Congress. However, if the US is directly providing the nuclear core for the subs, Congressional approval may not be necessary.
Wolfsthal highlighted the AUKUS program as a comparison point but noted that the expected size of AUKUS-class submarines may not fit South Korea’s needs. Kim suggested that a 4,000-ton nuclear-powered version of South Korea’s Jangbogo-IV class submarine would be more suitable than the American Virginia-class subs, which he considers too large and expensive. He added that the AUKUS program includes the transfer of sensitive submarine technology that Washington may not want to share with Seoul.
Kim further proposed converting the Philadelphia shipyard owned by South Korea’s Hanwha into America’s third nuclear submarine shipyard using Korean budget funds, enhancing US submarine production capacity.
Koh agreed, pointing out that it may enable the US to bolster its shipbuilding capacity, address nuclear proliferation risks and create jobs at home while South Korea will get the submarine capability it desires.
„It might well therefore have been a win-win situation for both parties as a result,” Koh concluded.
