Tokyo: Japanese officials are likely to start discussions on possessing nuclear-powered submarines, whose ability to undertake long military operations secretly will help strengthen deterrence against China’s maritime assertiveness.

According to Philippines News Agency, the ruling Liberal Democratic Party and Nippon Ishin no Kai (Japan Innovation Party), as part of their coalition agreement in October, pledged to promote the country’s possession of submarines powered by a next-generation energy source and equipped with a vertical launching system (VLS) for long-range missiles.

Defense Minister Shinjiro Koizumi stated on television on November 6 that “the environment surrounding Japan is so severe that we have to discuss whether to use diesel as we’ve done so far or nuclear power.” The Maritime Self-Defense Force (MSDF) currently possesses submarines powered by diesel engines and lithium-ion batteries, which make it necessary for them to regularly surface and take in air to recharge batteries. Nuclear submarines do not have to do the same, enabling them to stay submerged for a long time.

The introduction of nuclear submarines would require at least three vessels for a routine of maintenance, drill, and mission. However, their maintenance costs would be substantial, necessitating a review of the MSDF’s structure, which is already grappling with serious personnel shortages. Additionally, the MSDF would need to secure nuclear engineering experts to handle potential radiation leaks.

There is a possibility that officials might need to revise the country’s atomic energy basic law, which stipulates the peaceful use of nuclear power, or at least reinterpret it. Understanding and acceptance from locals in potential homeports and anchorage sites are also deemed necessary. A Defense Ministry official remarked that “the introduction of nuclear submarines has been a taboo subject in the SDF for a long time and has not been properly discussed,” adding that the decision depends on political readiness.

Another ministry official expressed skepticism, stating, “If it is only to monitor and deter China and Russia, it is enough to protect areas around Japan, so I wonder whether nuclear submarines are really necessary.”