From the ashes of Hiroshima and Nagasaki emerged a pacifist Japan - constitutionally bound to renounce war and nuclear weapons. Yet today, evolving regional threats and strategic anxieties are reviving a once-unthinkable nuclear debate in Tokyo.

Introduction

One of the most vicious chapters of history was the atomic bombing of Hiroshima and Nagasaki in Japan. The ultimate surrender of the Japanese forces and the post-WWII dynamics completely reshaped Japan’s constitutional playbook. Despite being the first-ever victim of a nuclear attack, Japan was permanently restricted from acquiring an offensive force and nuclear weapons. However, Japan was permitted to form a defensive alliance with the US.

Despite having proper know-how and technological supremacy, the fear of nuclear weapons among the public and a firm US commitment, restrained Japan from developing nukes. However, in recent years, a kind of nuclear debate has restarted in Japanese strategic circles. Although this does not explicitly mean that Japan will be altering its constitutional obligations in the short term, it reflects a re-emergence of discussions over nuclear and deterrence issues.

Historical Perspective

Japan covertly carried out research and development on nuclear weapons during World War II and developed a comprehensive nuclear fuel cycle system and cutting-edge nuclear industry skills. After Japan’s surrender, the United States forbade Japan from developing nuclear weapons. The Potsdam Proclamation prohibited Japan, a surrendered country of World War II, from having industries that would allow it to rearm and wage war.

Article 9 of the Japanese constitution states that, “Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes. In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained.”

The Atomic Energy Basic Act, passed in 1955, stipulates that research, development, and utilization of nuclear energy in Japan are admissible to be utilized in peaceful causes, and that they should be directed towards ensuring safety.

Non-Nuclear Principles

In 1967, Japanese Prime Minister Eisaku Sato first explicitly articulated the three non-nuclear principles, which became the foundation of Japan’s defensive constitutional buildup. The three principles include:

-       Japan will never possess nuclear weapons.

-       It will never produce nuclear weapons.

-       It will not permit the introduction of nuclear weapons into Japanese territory (extended nuclear deterrence).

Revival of Nuclear Debate

The former Japanese PM Shinzo Abe intended to – and made every effort to – amend the constitution, especially Article 9, in 2014. Abe yearned to rectify the ‘Peace Constitution’ of Japan in such a way that, in forthcoming times, it clearly stipulated that Japanese armed forces could come to the rescue of allies during an assault. This is known in Japan as the right of ‘collective self-defense.’ The amendment would have also increased Japan’s ability to respond effectively to any attack on the Senkaku Islands in the East China Sea. However, due to parliamentary restrictions, this was never done.

“Japan is capable of going nuclear virtually overnight.” (V.P. Joe Biden, 2016)

In a similar vein, in February 2022, former Prime Minister Shinzo Abe proposed that Japan “share” in the ownership of nuclear weapons, as some NATO members do, given Ukraine’s history of abandoning nuclear weapons and the current Ukraine situation. In addition to advocating for debate on this topic, the current Japanese PM, Sanae Takaichi, also argued that one of the three (non-)nuclear principles of “not allowing” nuclear weapons to be brought to Japan should have an exception “in the event of a contingency.”

By October 2025, Sanae Takaichi was elected to become the first Japanese woman Prime Minister. On the same line as her predecessor, PM Takaichi is currently seeking a more offensive and aggressive approach to potential threats in the region. In her recent remarks, retreating from Japan’s official position, PM Takaichi declared any attack on Taiwan as a national security concern for Japan. This resulted in a stark diplomatic standoff between China and Japan.

According to Japanese government sources, Prime Minister Takaichi is contemplating revising Japan’s long-standing policy of not possessing nuclear weapons as of November 14, 2025. Prime Minister Sanae Takaichi responded to a question on December 23, 2025, regarding Japan’s potential introduction of nuclear-powered submarines by stating that ‘policies would be evaluated to enhance deterrence and response capabilities without dismissing any options’.

Rationale Behind Nuclear Appetite

-       The right-wing political factions of Japan have long been demanding constitutional amendments and a kind of self-sufficiency with regard to defence and security. The ever-increasing far-right popularity in Japan is the primary cause.

-       The changing geopolitical environment, with the US under President Trump pursuing a conservative foreign policy, compelling allies to take a greater share of their defence, is another major force behind Japan’s nuclear revival.

-       Security concerns from China and North Korea and conflicts in the East China Sea over disputed island territories provide further impetus to the resurgence of Japanese militarism.

-       Historical evolution and gradual dissemination of the idea of strategic autonomy by various Japanese leaders and officials play a pivotal role in current reforms.

China’s Report on Japan’s Nuclear Ambitions

As of January 2026, two leading Chinese think tanks on disarmament and nuclear strategy have released a report against the expanding nuclear ambitions of sections of the Japanese establishment. The report titled “Nuclear Ambitions of Japan’s Right-Wing Forces: A Serious Threat to World Peace” warned the entire international community of the revival of Japanese militarism. The report provided the following facts and figures:

-       Japan is the only State, amongst the NPT signatories, that has mastered reprocessing technology and is technically empowered to make weapon-grade plutonium.

-       By December 2024, Japan had a total of 44.4 tons of separated plutonium in stock, many times more than was required to supply its civilian nuclear energy program.

-       The nuclear reactor technologies are quite developed in Japan; hence, this offers a technical foundation of research, design, and engineering involving nuclear propulsion of submarines and aircraft carriers.

-       Japan has a latent military capability, i.e., Tomahawks, and can launch nuclear weapons both at sea and on land.

Implications and Repercussions

Just assume that Japan once again becomes an offensive state. Cruelties against innocent civilians by the Japanese army cannot be forgotten in history, especially the Nanking Massacre and the Unit 731 operation. If Japan continues to pursue the same trajectory under the influence of its right-wing political parties, it could destabilize East Asia.

“History has noted that the sheer concentration of power in government is lethal - that only a sense of absolute unchecked power can make atrocities like the Rape of Nanking possible.” (Iris Chang)

Japan’s nuclear ambitions are a national security concern for the PRC. This might provoke China to step further to deter any potential aggression from Japan. Likewise, a chain reaction could start. Viewing Japan’s nuclear revival, regional entities like South Korea, the Philippines, and Australia might pursue their own nuclear programs.

To date, Japan is considered a prime example of anti-nuclear identity. If Japan acquires nuclear weapons, the international nuclear order would diminish. Even regions that are nuclear-free zones, such as Southeast Asia, may find it necessary to have nuclear weapons as a way of survival. All the nuclear non-proliferation and disarmament efforts would be derailed. As of today, the East Asian region already harbours plenty of territorial conflicts. Japanese offensive moves could trigger these regional hotspots.

In addition, a militarised and nuclear-powered Japan is itself disastrous for the US, given the fact that it was the US that destroyed Japanese cities, and these are the kinds of wounds that time does not heal completely.

Moreover, Japan might also get political backlash from the indigenous communities, especially those who witnessed the nuclear bombings and their repercussions. A civil war could break out, whereby different groups clash with one another, which could further worsen the crisis.

Conclusion

Japan is reawakening its nuclear ambitions, which changes the status quo of the region. Nonetheless, this would be very catastrophic as far as the history of war crimes in Japan is concerned. Moreover, public resistance could play a significant role in curbing the rising wave of militarism in Japan. The major powers and international organisations must preserve the rule-based order to contain the rising tides of militarism and nuclear proliferation. The current international order was built to save the future generations from the scourge of war. If not controlled, a single offensive move could throw all of humanity into chaos.

Aleena Im is an independent researcher and writer and is interested in international relations and current affairs. Courtesy

https://journal-neo.su/2026/02/07/revival-of-japans-nuclear-ambitions/