As the US and Israel attack Iran’s nuclear infrastructure, China is highlighting what it calls secret Japanese ambitions not only to produce nuclear weapons but also to become the world’s largest nuclear power.
On March 31, the US and Israel attacked Iran’s nuclear sites in Isfahan with bunker buster bombs for the second time in a year.
As of early 2026, Iran has stockpiled over 400 kg of 60%-enriched uranium, according to The New York Times and Time Magazine reports, with estimates suggesting this is enough for approximately a dozen nuclear bombs if further refined to 90%. The stockpile is primarily stored at the Isfahan nuclear facility.
Now, amid the Iran War, China is highlighting Japan’s nuclear ambitions.
Ironically, both Iran and Japan were among the earliest signatories of the Nuclear Non-Proliferation Treaty (NPT). Both Iran and Japan signed the NPT even before the treaty entered force on March 5, 1970.
China’s state-run military mouthpiece, the PLA Daily, on March 30 issued a rare full-page report, accusing Japan of “dangerously expanding” its defense industry in capacity, technology, and international engagement.
Warning that Tokyo has “crossed a red line,” the report claimed that Japan possessed an “astonishing” stockpile of nuclear materials and that it had the technology to produce nuclear weapons.
The “astonishing” stockpile of nuclear materials, according to the report, referred to 44.4 tonnes of plutonium, which had already been separated by the end of 2024.
The 44.4 tonnes of plutonium, the report claimed, was enough to make about 5,500 nuclear warheads.
Interestingly, according to SIPRI, Russia, the world’s largest nuclear power, has a stockpile of 5,400 nuclear warheads.
So, the report claims that Japan could not only produce nuclear weapons, but also emerge as the world’s largest nuclear power.
The report further warned that once Japan decides to remove the self-imposed restrictions under its Three Non-Nuclear Principles, Tokyo “could become a de facto nuclear-armed state in an extremely short period of time”.
First articulated by Prime Minister Eisaku Satō in 1967, and formally adopted as a parliamentary resolution in 1971, the Three Non-Nuclear Principles are (i) not to possess nuclear weapons, (ii) not to produce nuclear weapons, and (iii) not to permit the introduction of nuclear weapons into Japanese territory.
It said Japan had worked “systematically” to cultivate its defense industry “under the cover of civilian technology” and that had laid the groundwork for “a strategic shift in defense policy and unleashing its military-industrial potential”.
Tokyo allocated a record 17.5 billion yen (US$109.6 million) to its advanced technology transition research program in 2025 – 18 times the amount in 2022, the South China Morning Post (SCMP) reported, quoting the report.
Notably, the figure of Japan possessing 44.4 tonnes of plutonium, enough for thousands of nuclear warheads, was reported last year by the Japanese media itself.
Japan’s plutonium reserves stood at 44.4 tons as of late 2024, which was enough to make several thousand nuclear warheads, Japan’s Kyodo news agency reported in August last year.
According to the agency, Japan’s plutonium is stored both inside the country and in the United Kingdom and France, where radioactive waste from Japanese nuclear plants is processed into plutonium that could be used for military purposes.
According to the Japan-ASEAN Integration Fund (JAIF), about 8.6 tons of plutonium were stored in Japan, and about 35.8 tons were stored abroad, approximately 21.7 tons in the United Kingdom and about 14.1 tons in France.
The PLA report also warned about Japan’s dangerous remilitarization drive, which had gone far beyond the development of “defence-oriented” capabilities.
“It has now entered a new phase characterised by the large-scale development of long-range offensive capabilities, marking Japan’s total departure from its post-war pacifist trajectory,” it said.
In 2022, under the National Defense Strategy, Japan eased the self-imposed restrictions on acquiring long-range strike capabilities, paving the way for the development of long-range missiles.
Notably, in January this year, Beijing banned exports of commercial and military “dual-use” goods to Japan and blacklisted 20 Japanese entities in February.
The Japanese companies banned by China included big names, such as Mitsubishi Heavy Industries (MHI), Kawasaki Heavy Industries (KHI), and IHI.
These companies, the report said, played a role in Japanese aggression during World War II and were now “pioneering the rearmament of the country” and “potentially reviving militarism”.
It said MHI had acquired key technologies for stealth aircraft and ballistic missile defence systems through its cooperation with the United States in producing the F-35A fighter jet and the SM-3 Block IIA missile. It had also secured big foreign contracts, including a US$6.8 billion deal to build warships for Australia and deliveries of Patriot missile systems to the US.
Japan’s drive towards remilitarization, the report warns, resembles the rise of militarism before World War II, and it would “further bind defence spending with the interests of specific industries and zaibatsu-style conglomerates, creating a self-reinforcing, accelerating feedback loop between policy and vested economic interests”.
“When the gears of the defence industry begin turning again for the revival of militarism, Japan’s war machine probably will be reignited,” it said.
While the report is alarmist, Japan has, in recent years, removed a number of self-imposed restrictions on its military-industrial complex.
For instance, in 2014, Japan reinterpreted its constitution to allow Tokyo to exercise the right to collective self-defense in certain situations, specifically when an armed attack on a close ally threatens Japan’s own survival.
Last year, Prime Minister Sanae Takaichi said that an armed attack on Taiwan by China could constitute an “existential threat” to Japan, thereby opening the possibility of a Japanese military response in such a scenario.
Similarly, Japan has eased its self-imposed restrictions on the export of lethal weapons to foreign countries.
Again, in 2022, under the National Defense Strategy, Japan eased the self-imposed restrictions on acquiring long-range strike capabilities, paving the way for the development of long-range missiles.
Furthermore, in December last year, Japan passed a record USD 58 billion defense budget, with a plan to increase defense spending to more than 2% of GDP in the coming years.
Also, this is not the first time that China has warned the world about Japan’s remilitarization drive or its secret nuclear weapons ambition.
In January this year, Beijing released a 30-page report that included a call for the international community to ‘take concrete and strong measures’ against Japan’s nuclear ambitions.
“Japan may already have produced weapons-grade plutonium in secret and has the technological and economic capabilities to achieve nuclear armament in a short period of time,” the report said.
It also cited a remark made by former US President Joe Biden that Japan had the capacity to have nuclear weapons “virtually overnight”.
Biden first gave the information in an interview with the American public broadcaster PBS in June 2016.
“What happens if Japan, who could tomorrow, could go nuclear tomorrow? They have the capacity to do it virtually overnight,” Biden said when recalling a conversation he had with Xi.
The 30-page report titled “Nuclear Ambitions of Japan’s Right-Wing Forces: A Serious Threat to World Peace” was produced jointly by the China Arms Control and Disarmament Association (CACDA) and the Nuclear Strategic Planning Research Institute, a think tank affiliated with the China National Nuclear Corporation.
Furthermore, the report said, Japan maintained operational platforms with nuclear weapons delivery capabilities and had the technological foundation to develop nuclear-powered submarines and aircraft carriers.
Notably, Japanese Prime Minister Sanae Takaichi and former Prime Minister Shinzo Abe have indeed suggested revisiting Japan’s nuclear policy.
Prime Minister Takaichi has previously suggested in her writings that Japan’s reliance on the U.S. nuclear umbrella makes the principle of prohibiting nuclear weapons on Japanese soil increasingly unrealistic.
Similarly, in 2022, former Prime Minister Shinzo Abe suggested that Tokyo should share nuclear weapons with the US.
Japan has enjoyed the protection of the United States’ nuclear umbrella for more than 60 years. However, Tokyo’s self-imposed restrictions on the introduction of nuclear weapons on Japanese territory do create practical problems in enforcing this protective nuclear umbrella in an effective manner.
Takaichi has also shown her openness to acquiring nuclear-powered submarines.
However, it must be noted that these remarks signaling Tokyo’s openness to revisiting its nuclear policy have faced strong opposition within Japan.
While China is exaggerating the nuclear danger emanating from Japan for obvious reasons, these remarks from senior Japanese politicians, including serving and former prime ministers, do suggest that Tokyo’s nuclear policy is, indeed, undergoing a churning, and as security risks escalate, Japan can also revisit its commitments under the Three Nuclear Principles.
Notably, three of Japan’s neighboring countries with whom Tokyo shares an adversarial relationship have nuclear weapons: China, North Korea, and Russia.
The PLA Daily report claims that Japan has enough plutonium to produce 5,500 nuclear warheads.
Clearly, the number is meant to shock the world and international community into bringing their focus on Japan’s nuclear ambitions. Still, it can not be denied that a lot of influential voices in Japan are demanding that Tokyo revisit its self-imposed restrictions on nuclear weapons.
- Sumit Ahlawat has over a decade of experience in news media. He has worked with Press Trust of India, Times Now, Zee News, Economic Times, and Microsoft News. He holds a Master’s Degree in International Media and Modern History from the University of Sheffield, UK.
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- He can be reached at ahlawat.sumit85 (at) gmail.com
