South Korea plans to build and launch its first nuclear-powered attack submarine by the mid-2030s [1].
The initiative represents a significant shift in the region's naval capabilities. By deploying nuclear-powered vessels, Seoul aims to enhance its ability to monitor and counter underwater threats in the Indo-Pacific, particularly near the First Island Chain.
The Ministry of National Defense announced the program on May 26, 2026 [1]. The government intends for the first vessel to enter service in the mid-2030s [2], marking a transition from conventional diesel-electric submarines to long-endurance nuclear propulsion.
Officials said the move is designed to counter North Korea's submarine-launched nuclear and missile threats [1]. Nuclear-powered submarines can remain submerged for much longer periods and travel faster than conventional boats, providing a critical advantage in stealth and persistence.
Beyond the peninsula, the program is intended to strengthen U.S.-aligned deterrence against China and other potential adversaries [1]. The strategic positioning of these assets near the First Island Chain is expected to alter the underwater balance of power in the region [4].
South Korea has previously focused on conventional submarine technology, but the increasing sophistication of regional threats has prompted this shift toward nuclear power [3]. The development process will require significant technical advancements in reactor design, and crew training to meet the mid-2030s deadline [2].
“South Korea plans to build and launch its first nuclear-powered attack submarine by the mid-2030s.”
The shift to nuclear propulsion allows South Korea to maintain a persistent presence in contested waters without the need to surface frequently for air and fuel. This capability directly challenges the naval reach of North Korea and adds a new layer of strategic depth to the U.S.-led security architecture in the Indo-Pacific, potentially escalating the underwater arms race between regional powers.
