At the very end of last year, Japan found itself at the center of an unusually intense domestic and international debate over its long-standing policy of refusing to develop nuclear weapons, Kyodo news agency reported. The immediate reason for the renewed discussion about the future of Tokyo's three nuclear principles - not to possess, not to produce and not to allow the deployment of nuclear weapons on its territory - was a comment by a government security adviser close to Japanese Prime Minister Sanae Takaichi, who publicly stated that "Japan must possess nuclear weapons" to deal with the increasingly difficult security situation, BTA summarized.
The comment caused a wide resonance in political and media circles, partly because it came at a time when the government was already increasing defense spending and military reforms, Reuters notes.
The Chinese state news agency "Xinhua" interpreted the adviser's comment as a sign of a broader trend among "right-wing forces" in Japan towards rearmament and challenging post-war norms – including discussions on revising security treaties and even the nuclear principles themselves.
Japanese Chief Cabinet Secretary Minoru Kihara was quick to clarify that
there is no official change in Japan's nuclear policy and confirmed that Tokyo does not seek to develop, possess or accept nuclear weapons on its territory.
Kihara stressed that the government official's statement did not reflect the government's position. However, this episode demonstrates that nuclear policy - long considered a taboo subject in Japan - is now being openly discussed at high levels in a way that would have been almost unthinkable just a decade ago, Reuters commented.
At the heart of Japan's nuclear policy are the three nuclear principles, first formulated in 1967, which explicitly commit the country not to possess, produce or allow nuclear weapons on its territory. The principles are enshrined in a number of policy documents and have long shaped both the country's diplomatic stance and public opinion in Japanese society, the agency said.
This framework is underpinned by Japan's pacifist constitution - particularly Article 9, which prohibits the waging of war and limits military action to self-defense - as well as by the memory of the atomic bombings of Hiroshima and Nagasaki, says the atomic bombing survivors' organization "Nihon Hidankyo". The organization has publicly opposed any weakening of these principles, consistently calls for adherence to non-proliferation values and warns that the debate over nuclear weapons could undermine Japan's identity as a peace-oriented country.
Experts note that this strong normative basis represents a significant obstacle to a possible change in the country's nuclear policy. A possible turnaround would require overcoming decades of deep-rooted legal and cultural aversion to nuclear weapons, which is undoubtedly an extremely difficult political task, Reuters commented.
The debate over nuclear weapons has gained even greater publicity due to changes in the regional strategic environment, Kyodo noted. China's growing military capabilities, combined with its growing nuclear arsenal and its aggressive posture in the East China and South China Seas, are a source of concern in Tokyo. The same applies to North Korea's missile and nuclear programs. Some analysts say that the changing balance of power in the region is putting pressure on Japan to reconsider its security strategy.
According to Xinhua, Chinese nuclear experts believe that Japan's technological and industrial base is such that it could develop nuclear weapons in less than three years if the political will exists, in line with warnings from commentators such as the late Henry Kissinger about the long-term possibility of Japan developing nuclear weapons.
Reuters highlights that US allies in Asia - including South Korea - have recently begun to have doubts about the reliability of the US nuclear deterrent, which in turn has sparked debates about developing their own deterrent capabilities.
In Japan itself, some members of the ruling Liberal Democratic Party have publicly begun discussing a review of nuclear principles, not with the aim of creating a nuclear arsenal overnight, but as part of a rethinking of the country's positions in the face of changing geopolitical pressures, the Chinese newspaper "Global Times" wrote.
The Japanese newspaper "Japan Times" in turn quoted analysts who stressed that growing global tensions, not just regional threats, are changing the tone of the discussion about nuclear weapons. Strategic uncertainty, changing U.S. commitments and the evolving nature of nuclear deterrence mean that the debate over nuclear weapons in Japan is no longer confined to academic circles dealing with security issues, the publication notes.
At the same time, other analysts argue that fears of a possible nuclear program in Japan are exaggerated, Reuters points out. They say that Japan's technological capacity is only one side of the coin - the political, legal and diplomatic obstacles are much greater, and public opinion remains strongly negative about nuclear weapons. Public opinion in Japan is still strongly supportive of nuclear principles, the agency comments. Non-governmental groups, organizations of bombing survivors and representatives of civil society are mobilizing against any proposal to change the country's nuclear policy.
Internationally, the debate in Japan has provoked mixed reactions,
Reuters commented. While Beijing and Pyongyang have condemned even the discussion of the topic, interpreting it as an attempt to make veiled threats or disrupt regional stability, US allies are watching the discussion with a mixture of strategic concerns and understanding of Tokyo's dilemma.
A number of analysts emphasize that if Japan ever decides to acquire nuclear weapons - or even to revise its nuclear principles - this would have profound consequences for the regime of the Nuclear Non-Proliferation Treaty and for global non-proliferation norms, Reuters points out. A nuclear-armed Japan would challenge the post-Cold War world order, which has been characterized by limiting the number of warheads in nuclear arsenals and the proliferation of nuclear weapons.
After all, the very fact that such discussions - once considered taboo - are now taking place reflects major changes in the strategic context in East Asia, writes "Foreign Policy" magazine. Regional threats from China, North Korea, and broader questions about the reliability of U.S. deterrence have renewed the debate not only in academic publications but also in policy circles that influence political discourse and public debate.
It is important to note that the debate remains fierce and the parties are far from consensus, notes "Foreign Policy". The question may be when and how discussions will progress, rather than whether they will at all, given the security tensions Japan is facing.
For now, Japan’s nuclear policy remains unchanged, but 2025 was a turning point that launched a discussion on strategic issues of deterrence, the credibility of alliances, and the future shape of nuclear nonproliferation norms in the Asia-Pacific region. Whether these debates lead to policy changes in the coming years will depend on both external threats and developments in Japan’s domestic political climate, the paper concludes.