Tokyo is considering a change but legal constraints and pacifism weigh heavily
The Japanese government will “seriously evaluate” the possibility of equipping the Self-Defense Forces (SDF) with nuclear-powered submarines, in light of the growing military activity of neighboring countries. Prime Minister Sanae Takaichi declared this in a hearing in Parliament, defining the strengthening of defense as “urgent” and noting the limited capabilities of the SDF in gathering information and surveillance in the Pacific. This is a clearer opening than at the beginning of the month, the Japanese media report, when he stated that “nothing has been decided at the moment”.
In the Land of the Rising Sun the issue remains delicate: the law limits the use of nuclear power for peaceful purposes, and previous governments have ruled out that it could power SDF submarines. Japan has long adhered to the three non-nuclear principles, which prohibit the possession, production and introduction of atomic weapons on the territory. According to government sources cited by the Kyodo agency, it is being considered to mention nuclear submarines as an option for deterrence in the update of strategic documents on defense and security, expected within the year.
The executive will take into account developments in partner countries such as Australia, which has decided to acquire these units, and South Korea.
Since taking office in October 2025, Takaichi has accelerated military spending. The target of 2% of GDP, set for the 2027 fiscal year, was reached two years early, after Parliament gave the green light to an additional allocation: a turning point compared to the informal ceiling of 1% which remained in force until 2022. The choice is part of pressure from Washington, where the Trump administration reportedly urged Tokyo to increase up to 3.5%. Takaichi argued that there were no “exchanges with numbers in mind”, while the government motivates the rearmament with regional tensions.
