South Korea advances nuclear submarine program with US backing

South Korea’s pursuit of nuclear-powered submarines is gaining momentum after President Donald Trump endorsed the program, ending decades of US opposition and potentially reshaping Asia’s security landscape. The move, which grants Seoul access to nuclear fuel under a bilateral agreement, could trigger an underwater arms race, analysts warn.

Seoul has long sought nuclear submarines to counter North Korea’s growing undersea capabilities, including submarine-launched ballistic missiles. “Submarines are highly effective attack systems. An arms race in the region is inevitable,” said Choi Il, a retired South Korean Navy submarine captain, Reuters reports.

President Lee Jae Myung described the agreement as a major achievement following his meeting with Trump, noting it would enhance security flexibility and defence autonomy. South Korea maintains it will not acquire nuclear weapons and remains committed to the non-proliferation regime.

North Korea claims to be developing similar capabilities, with state media showing leader Kim Jong Un inspecting a purported nuclear-powered submarine in March. Analysts speculate Pyongyang may be receiving Russian assistance, which Seoul says it is monitoring closely.

South Korean lawmaker Yu Yong-weon highlighted that nuclear-powered submarines, capable of staying submerged far longer than diesel counterparts, would improve monitoring of North Korean vessels. “This could also push Japan to rethink its stance,” he added. Japan, which currently relies on smaller diesel submarines, has said nuclear propulsion is a potential option, though no studies are underway.

The initiative aligns with US objectives to counter China’s regional influence. Admiral Daryl Caudle, US Chief of Naval Operations, described China as a “pacing threat” and noted Seoul’s nuclear submarines could play a future role in deterrence.

China has reacted cautiously, while North Korean media warned the plan could trigger a “nuclear domino” effect. South Korea has assured Beijing that its submarines are defensive and aimed at deterring North Korea, according to national security adviser Wi Sung-lac.

Only six countries currently operate nuclear-powered submarines: the US, Russia, China, France, India, and the UK, with Australia developing a fleet under the 2021 AUKUS agreement. South Korea has independently advanced its submarine designs, with Defence Minister Ahn Gyu-back estimating it could build vessels within 10 years. “Rather than calling it approval from the US, we had already prepared the conditions to build nuclear-powered submarines, and fuel was the final piece we needed,” he told parliament.

A White House official affirmed US support for Seoul’s program, noting it would enhance alliance deterrence and burden-sharing in the region.

By Vafa Guliyeva