On 26 April 2026, Ukraine marked 40 years since the Chornobyl disaster. Once associated with the worst catastrophe of the nuclear age, Ukraine is again at the centre of a global nuclear crisis, but of a different kind. The danger now lies not only in military escalation or new accident, but in the transformation of civilian nuclear infrastructure into an instrument of war — a possibility for which the international nuclear order remains poorly prepared.
The Chornobyl catastrophe reshaped both Ukraine’s political trajectory and international approaches to nuclear risk. As the historian Serhii Plokhy has argued, Soviet secrecy deepened the regime’s crisis of legitimacy and helped turn environmental mobilisation into broader demands for accountability and, eventually, independence. Internationally, the disaster accelerated new transnational mechanisms of nuclear cooperation and safety governance.
The end of the Soviet Union perpetuated a clear asymmetry: Russia remained a nuclear-weapon state, while Ukraine relinquished its arsenal and joined the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) as a non-nuclear state, a settlement politically sealed by the 1994 Budapest Memorandum (violated in 2014 by Russia). Yet despite the trauma of Chornobyl, civilian nuclear power became central to independent Ukraine and increasingly associated with its energy and political sovereignty.
In 2022, Russia’s full-scale invasion brought war directly into this nuclear landscape. On the first day of war, Russian forces occupied Chornobyl and seized the Zaporizhzhia Nuclear Power Plant (NPP) days later. Europe’s largest nuclear station was progressively incorporated into the mechanics of occupation through the intermediary of Rosatom, Russia’s biggest state nuclear corporation.
This situation exposes the fragility of the distinction between the “peaceful” and “military” atom. International law recognises the exceptional risks surrounding nuclear installations, but the existing order was not designed for the prolonged occupation of an operating NPP —particularly when it is perpetrated by a permanent member of the United Nations Security Council.
The warning extends far beyond Ukraine. Rosatom remains a major global nuclear actor, with projects across Europe, Asia, and Africa, and its international reach has proved remarkably resilient since 2022, with an annual revenue growth of 24 %. The Ukrainian case therefore projects a grim possibility into the future, in which the militarisation of civilian nuclear infrastructure turns into a source of permanent nuclear threat.
If 1986 showed that nuclear accidents cannot be treated only nationally, the war in Ukraine shows that nuclear safety can no longer be conceived as a peacetime problem. Forty years after Chornobyl, the challenge is to rethink an international nuclear order, confronting a reality largely left outside the frame by its architects: that the “peaceful atom” itself can become an instrument of war.
This article was published in Globe #38, the Graduate Institute Review.
