Tokyo Report | Security | East Asia

Japan’s Nuclear Taboo Is Starting to Crack

Whether or not Japan’s nuclear policy is actually revised, the very fact that such a revision is being openly debated is a striking development.

August has been a solemn month in Japan for more than 80 years. Although Japan formally signed the Instrument of Surrender on September 2, 1945, the atomic bombings of Hiroshima and Nagasaki on August 6 and 9, respectively, and Emperor Hirohito’s radio announcement on August 15 accepting the terms of surrender have made August a month from which the Japanese psyche cannot escape. Every year since the Pacific War ended in Japan’s defeat, during August the nation has mourned its war dead and reflected on the horrors of a conflict that inflicted immense suffering and destruction upon the country. The resolve that Japan must never again endure such an ordeal lingers in the air of the sweltering Japanese summer.

But this year, another issue besides the memory of war has been generating heated debate in the Japanese media: will the Takaichi administration revise the government’s Three Non-Nuclear Principles in the upcoming revision of Japan’s national security documents? 

Japanese media outlets have been closely scrutinizing Takaichi’s remarks on Japan’s Three Non-Nuclear Principles, under which Japan pledges not to possess, produce, or allow the introduction of nuclear weapons into its territory. This attention stems from Takaichi’s previous position that at least the principle concerning the non-introduction of nuclear weapons should be reconsidered in the interests of Japan’s national security. In an edited volume she published in 2024, Takaichi even argued that Japan’s current nuclear policy was not “realistic” when it came to ensuring the credibility of the U.S. extended nuclear deterrent.

The fact that she has not categorically ruled out revising the principles since becoming prime minister has fueled speculation that she could embark on a major shift in Japan’s decades-old nuclear policy – essentially distancing the country from its longstanding commitment to refrain from assuming any role in the deployment of nuclear weapons, even for defensive purposes. 

Questioned about her current stance on Japan’s nuclear policy, Takaichi has maintained that her government “remains committed to the Three Non-Nuclear Principles as a matter of policy.” At the same time, she has declined to “say definitively what their final wording will look like” in the revised security documents. In other words, Takaichi has reiterated – even on the anniversaries of the atomic bombings of Hiroshima and Nagasaki – that the existing nuclear policy remains in place for now, while leaving open the question of how nuclear weapons will be addressed in the future.

Defense Minister Koizumi Shinjiro, Takaichi’s point man for drafting the new national security policies, has also hinted that a revision of Japan’s nuclear policy may be on the table. Appearing on a conservative online program, Koizumi acknowledged that nuclear weapons are “a difficult issue for Japan to discuss,” but argued that it is one that cannot be avoided. 

He went further, saying that “we must recognize the sense of crisis we face and discuss and pursue every possible policy option without treating anything as taboo.” He also referred to the efforts of Finland and France to strengthen their nuclear deterrence. For Koizumi, preserving existing policies should not take priority over........

© The Diplomat