Seoul’s strategic upgrade draws regional warning

South Korea is moving ahead with plans to build nuclear-powered submarines after receiving approval from the United States — ending decades of resistance to such a move. Leaders say the decision will strengthen the country’s undersea defenses against threats from North Korea. But the step is also raising concerns in neighbouring capitals, including Japan and China, over triggering a regional submarine arms race.

Seoul argues the submarines are defensive—designed to patrol longer and operate stealthily in waters where North Korea maintains a robust undersea force. The U.S. backing, analysts say, reflects Washington’s broader aim to counter Chinese influence in Asia. In Japan, there is rising pressure to consider similar capabilities. In Beijing, reaction has been muted publicly, but many expect Beijing to quietly ramp up its own maritime deterrence in response. Security experts warn this could destabilize an already tense Indo-Pacific region by accelerating undersea militarization and shifting naval balances.