Japan is considering developing nuclear-powered submarines after a state-backed panel formally recommended research into “next-generation propulsion” systems for the Japan Maritime Self-Defense Force (JMSDF).
Submitted to the Ministry of Defense last September, the proposal marks the first time an official advisory group has opened the door to studying nuclear propulsion, signaling a potential departure from Japan’s long-standing policy limiting military use of nuclear energy, Army Recognition reported.
Push for Longer-Range, Stealthier Submarines
The panel said Japan’s next generation of submarines should travel farther, remain submerged longer, and carry long-range missiles, capabilities that may require propulsion systems beyond conventional diesel or battery power.
It also urged the Japanese Ministry of Defense to explore advanced solutions to improve endurance and stealth, stressing the need for submarines that can stay concealed and operational amid rising tensions in the Indo-Pacific.
“Nuclear-powered boats offer unmatched underwater mobility, stealth, and range,” said Kazuki Yano, a former JMSDF submarine commander, adding that Japan already has the industrial capacity to build them if permitted.
Legal, Political Barriers Remain
Despite the new strategy, Japan’s postwar laws still make such development difficult. The Atomic Energy Basic Act restricts nuclear technology to peaceful uses, while Japan’s “Three Non-Nuclear Principles” forbid manufacturing, acquiring, or receiving nuclear weapons.
Chief Cabinet Secretary Yoshimasa Hayashi also reiterated last year that the East Asian government has “no plans to possess nuclear submarines” under its current law.
Submarines in Japan
For now, Japan continues to expand its conventional fleet, with the JMSDF operating 22 submarines and planning to increase that number to 24 by the end of the decade.
Its newest Taigei-class submarines use lithium-ion batteries for quieter, longer underwater operations, while older Sōryū-class vessels are being upgraded with the same technology.
The AUKUS pact between the US, the UK, and Australia, which will give Canberra nuclear-powered submarines, has also renewed the debate on nuclear military capabilities in Tokyo.
Analysts said that Tokyo is watching the agreement closely as a possible model if it ever revisits its nuclear restrictions.
-
-
-
-
-
