Japan Maritime Self-Defense Force "Whale-class" submarine. (Picture taken from Japan’s Ministry of Defense)
[Compiled by Chen Chengliang/Comprehensive Report] Japanese Prime Minister Takaichi Sanae's government plans to revise the "National Security Strategy" and other security 3 documents before the end of the year, and internally there is a plan to include "research on the possession of nuclear-powered submarines" in the document. This will touch upon Japan's long-term policy of prohibiting self-defense ships from using nuclear energy for propulsion. Related discussions will enter the next stage as soon as late November.
Kyodo News reported on the 6th that at the expert meeting held by the Gao City Government to revise the Security 3 document, some people advocated the introduction of nuclear-powered submarines, while others took a cautious attitude. The Liberal Democratic Party's ruling ally, the Japan Reform Association, advocates early introduction, believing that nuclear energy is a necessary power option if submarines are to use shipborne vertical launch systems (VLS) underwater.
The "Yomiuri Shimbun" reported that if the new document writes "review holding" or "research holding" nuclear submarines, the Japanese government can further conduct investigation and research, including simulation applications and cost estimates, but this does not mean that Japan has decided to acquire nuclear-powered submarines. Sources pointed out that once the relevant content is written into the document, it will be easier to start detailed discussions regardless of whether it is ultimately held.
There is still a threshold for Japan’s nuclear-powered submarines
Japan has long adhered to the principle of peaceful use of nuclear energy and does not allow nuclear energy to be used as a propulsion power for self-defense ships. In 1965, the then head of the Science and Technology Agency proposed that self-defense ships should not use nuclear energy for propulsion, and the relevant policy continues to this day. Japan also adheres to the "three non-nuclear principles", namely not to possess, not to manufacture and not to introduce nuclear weapons.
The current proposal put forward by the Liberal Democratic Party deliberately uses the expression "utilizing next-generation power" and does not directly name nuclear energy. The Japan Reform Association’s views are more clear, believing that submarines with underwater VLS capabilities require nuclear power and requesting accelerated introduction.
Nuclear-powered submarines can maintain underwater navigation for long periods of time and are usually faster than conventionally-powered submarines. Therefore, supporters believe that they will help Japan perform vigilance and surveillance in surrounding waters and improve its deterrence capabilities. However, the construction cost of nuclear submarines is expected to be several times that of conventionally powered submarines, and the maintenance, repair and operation of nuclear power systems also require professional technology and talents.
The Japanese government expert meeting is expected to compile a report in late November at the earliest, and the ruling coalition will also coordinate relevant policies before and after. Defense Minister Shinjiro Koizumi and Chief Cabinet Secretary Minoru Kihara have previously stated that discussions on possessing nuclear submarines should not be ruled out, but there are still cautious opinions within the Liberal Democratic Party, and how to express the final document still needs to be coordinated.
