Japan weighs shift to nuclear-powered submarines amid rising Chinese naval activity

Japan is evaluating the possibility of replacing its diesel-electric submarines with nuclear-powered ones as it modernises its undersea force. Defense Minister Shinjiro Koizumi and the Liberal Democratic Party have expressed support for the shift, citing the need to strengthen national defence. The Institute for the Study of War argues that nuclear submarines provide superior range, speed and concealment, enabling Japan to contest Chinese naval expansion throughout the Pacific Ocean.

China’s fleet, now the world’s largest by ship count, continues to modernise, prompting regional security concerns. The think-tank also points out that nuclear submarines can carry more powerful weapons systems. Japan’s pacifist constitution and nuclear energy restrictions pose legal challenges to the plan, but recent defence policy changes have already pushed Japan toward a larger military posture.