China has raised concerns over Japan’s stockpile of nuclear material, arguing the country retains both the resources and industrial base to develop nuclear weapons if policy constraints were lifted.
According to the South China Morning Post, Japan had accumulated about 44.4 tons of separated plutonium by the end of 2024, a quantity that could be sufficient for around 5,500 nuclear warheads.
However, Tokyo’s policy framework is anchored in its Three Non-Nuclear Principles, which prohibit the possession, production, or introduction of nuclear weapons in the country.
In addition, the Asian nation’s Atomic Energy Basic Act restricts nuclear technology to peaceful uses, limiting any pathway to weaponization.
In this context, the Hong Kong-based news outlet argued that Japan’s advanced civilian nuclear infrastructure and technical base could, in principle, support a relatively rapid transition to weapons development if these constraints were to change.
It linked this assessment to Tokyo’s expanding defense industrial base, including closer integration between civilian and military technologies.
This comes amid recent measures by Beijing, including restrictions on dual-use exports and sanctions targeting several Japanese firms, among them major industrial groups such as Mitsubishi Heavy Industries, Kawasaki Heavy Industries, and IHI Corporation.
Rising Tensions
The report comes amid broader strain in relations between China and Japan, including over Taiwan.
In March, Tokyo announced plans to deploy long-range counterstrike missiles in its southwestern region, part of a wider effort to strengthen its military posture amid increased Chinese naval activity in the East China Sea.
Tensions have escalated since Japan’s Prime Minister Sanae Takaichi warned in November that a Chinese attack on Taiwan could trigger a Japanese military response. Beijing claims Taiwan as its territory and has not ruled out the use of force.
