Japan defense policy regarding nuclear-powered submarines

The Japanese government has signaled a potential shift in its long-term maritime strategy by considering the acquisition of nuclear-powered submarines to enhance deterrence in the Western Pacific.

Defense Minister Shinjiro Koizumi initially stated that the government would not rule out such capabilities, citing the regional security environment—specifically the expansion of China’s nuclear arsenal, North Korean missile advancements, and Russian nuclear threats—as reasons to move past traditional taboos.

Following this, Prime Minister Sanae Takaichi indicated that the government would engage in “concrete and realistic” discussions regarding the introduction of these vessels into the Self-Defense Forces. This policy shift is expected to be part of upcoming revisions to security-related documents.

The move is framed as a response to China’s increasing naval presence and its use of nuclear-powered submarines. However, implementation faces significant hurdles, including the high cost of vessels, the need for specialized personnel, and existing legal restrictions that limit nuclear use to peaceful purposes.