Japan Will Not Become a Nuclear Power

Among U.S. allies, the allure of nuclear weapons has never been greater. The new leader of Germany has advanced the idea of Europe developing its own “nuclear umbrella,” a discussion that is taking on new urgency. Poland wants to host some of NATO’s nuclear weapons. France is showing openness to extend its nuclear deterrent to wary European countries. In the Indo-Pacific, public support for acquiring nuclear weapons has reached an all-time high in South Korea.

The lust for nuclear weapons among traditional U.S. allies could be attributed to a single factor: U.S. President Donald Trump. The Trump administration’s flirtation with a Russia rapprochement – at the expense of Ukraine’s territory – and its interference in the domestic politics of European nations like Germany, Greenland, and the United Kingdom has spooked the continent as a whole, and imbued a sense that the United States will not protect them when it is necessary to do so.

Similar to its European counterparts, South Korean is considering the bomb in order to increase its options for security. At the moment, Seoul’s primary security provider is governed by a man who openly boasts about exchanging love letters with the leader of the South’s primary adversary, North Korea.

Against this backdrop, some observers predict – or even suggest – that Japan will follow the footsteps of other tormented U.S. partners. According to Patrick Tucker’s reporting for Defense One, former high-ranked U.S. officials are saying that if neighbors like South Korea come to possess the bomb “Tokyo would likely launch a [nuclear weapons] program of its own.” In response to U.S. Defense Sectary Pete Hegseth’s announcement that Ukraine’s surrender of some part of territory to Russia is inevitable, Noah Smith, an economic blogger, claimed that Japan “needs nuclear weapons immediately.” It is also worth noting that right before he passed, Henry Kissinger argued that Japan was "heading towards becoming a nuclear power in five years”

On one level, it is not surprising why some say that Japan is close to becoming a nuclear power. Japan is a country that relies heavily on the United States for its defense, and Washington is becoming increasingly unreliable. Japan is surrounded by three nuclear powers – China, North Korea, and Russia – all of which are willing to use force to achieve their objectives. Japan has the technology to build a nuclear weapon, as experts note.  And history shows that it is unlikely that a country with nuclear weapons would ever be invaded by a sovereign nation. Therefore, it’s logical to think that in order to maximize its security, one plausible path for Japan is to become a nuclear power.

However, despite the volatile international environment, the Japanese people have no intentions of ever developing nuclear weapons.

A study done in February by the Research Center for Advanced Science and Technology Open Laboratory for Emergence Strategies (ROLES), a think tank based at Tokyo University, showed the strong sentiment of the Japanese people against any possession or use of atomic weapons. According to ROLES, which surveyed 2,000 Japanese nationals from 18 to 79 years old, only 16.6 percent answered affirmatively that Japan should develop its own nuclear weapons, while 63.3 were either somewhat or firmly opposed to the idea.

The study also revealed that even stationing the nuclear weapons of an allied country – the United States – on Japanese soil, was unpopular. 59.7 percent of respondents were against it, leaving only 16.6 percent open to the proposition.

Not only do the Japanese people generally oppose the idea of their country having anything to do with nuclear weapons, but in an ideal world they want such devices erased from Earth. The survey found that 50.8 percent of the respondents think Japan should join the Treaty on the Prohibition of Nuclear Weapons (TPNW). Just 18.9 percent agree with the Japanese government that their country should not ratify the treaty.

Needless to say, Japan’s experience of being the first – and so far the only – country to suffer an atomic bombing has had a serious psychological impact on how Japanese people see the nuclear issue. The horrors and destruction of Hiroshima and Nagasaki are revisited every August, and passed down to new generations via peace education, memorial services, and tireless work by nationwide organizations, such as the Nihon Hidankyo, which won the Nobel Peace Prize in 2024. No one seriously advocating for the possession of nuclear weapons would be treated warmly in Japan today.

However, the study from ROLES highlights that while the Japanese people despise nuclear weapons, a significant majority perceive the bomb as a necessary tool for their nation’s security. Currently, Japan benefits from the nuclear umbrella provided by the United States, a treaty ally that is required to protect Japan if the situation requires. In response to the question, “Do you agree or disagree that Japan is protected by U.S. nuclear weapons?” 40.9 percent of respondents said yes; just 27.4 percent said no. This result shows that Japanese people see nuclear deterrence as a positive good for their defense and a functioning mechanism that defends the country from external threats.

Japanese people thus have a contradictory view on nuclear weapons – or one may see it as a principled stance rooted in the country’s acute understanding of both domestic constraints and the security environment. As the Trump administration progresses, there may be lively discussion within Japan to find an alternative solution to guarantee Japan’s security. But whatever the “Plan B” is, we can be sure it will stop short of Japan possessing nuclear weapons.