Japanese government officials are preparing to initiate discussions on the potential acquisition of nuclear-powered submarines, a strategic move aimed at bolstering deterrence against increasing Chinese maritime assertiveness.
The debate is fueled by a commitment made in October by the ruling Liberal Democratic Party (LDP) and Nippon Ishin no Kai (Japan Innovation Party) to explore possessing submarines that utilize a next-generation energy source and are equipped with a Vertical Launching System (VLS) for long-range missiles.
Defense Minister Shinjiro Koizumi underscored the urgency on Nov. 6, stating that the severe security environment mandates a discussion on transitioning from the Maritime Self-Defense Force’s (MSDF) current diesel-electric subs to nuclear power.
Unlike diesel-electric vessels, which must periodically surface to recharge, nuclear submarines can remain submerged for extended periods, providing crucial stealth and operational range for long-duration missions.
Implementing the VLS, essential for long-range missile capabilities, requires a large-hull, high-mobility submarine—a design consistent with nuclear power.
However, the proposal faces significant hurdles.
The MSDF would need to acquire at least three nuclear submarines, leading to massive maintenance costs and forcing a comprehensive review of the MSDF structure, which is already struggling with personnel shortages.
The service would also require highly specialized nuclear engineering experts to manage safety and potential radiation risks.
A Defense Ministry official noted that nuclear submarine introduction has long been a “taboo subject” and its success hinges on political determination.