Japan's government is considering mentioning the introduction of nuclear-powered submarines as it revises its so-called three security documents, the National Security Strategy, National Defense Strategy and Defense Buildup Program, the basic guidelines of defense policy. This is according to a Kyodo News report cited by the Kyunghyang Shinmun. The move comes as Prime Minister Sanae Takaichi's government speeds up a rework of security policy.

According to Kyodo, an expert panel to the government heard the view that Japan should introduce nuclear submarines to respond to China's active military operations in the Pacific. The Japan Innovation Party, a coalition partner, also urges early introduction, saying nuclear power is the only propulsion for a submarine that can operate vertical-launch missile systems underwater.

The long wall of 'peaceful use'

But the government may not presuppose owning nuclear submarines and may instead write only that it is a 'stepping stone for future study and discussion.' The practical constraints are large.

Successive Japanese cabinets, following a 1965 view of the Science and Technology Agency chief, have kept an interpretation that the Atomic Energy Basic Law's 'peaceful use' provision does not allow nuclear propulsion for Self-Defense Forces vessels. The chief cabinet secretary of the previous Shigeru Ishiba cabinet also said owning nuclear submarines is difficult under the current interpretation.

Caution exists within the Liberal Democratic Party too. Nuclear-powered submarines involve huge budgets and time, from construction and operation to nuclear fuel management and training personnel. Considerable friction is expected in the discussions ahead.

Neighbors' reactions and Korea's view

China and neighboring countries have watched changes in Japan's military power. Some see nuclear-powered submarines, which can stay submerged for long periods, as changing the nature of deterrence, and there is concern that the discussion alone could raise regional tension. Combined with Korea's pursuit of nuclear-powered submarines, some analysts say Northeast Asia's naval competition could enter a new phase.

A third view

The nuclear submarine discussion is both a domestic matter of Japan's constitutional and nuclear-law interpretation and a question of the regional security environment. Japan's government sees stronger defense capability as a way to raise deterrence, while neighbors may read it as a sign of rising tension. That is why voices say transparent explanation and keeping channels of dialogue open matter more than ever.