Nuclear Proliferation — 2026-04-27

Guterres Warns Nuclear Warheads Rising and Testing Back on the Table at NPT Review

Secretary-General Guterres told the opening session of the 11th NPT Review Conference on April 27 that, for the first time in decades, the number of nuclear warheads is "on the rise" and nuclear testing is "back on the table." Guterres cited unfulfilled commitments and accelerating proliferation drivers, calling on states to reinforce the norm against nuclear testing and strengthen IAEA safeguards. The conference, which runs through May 22 at UN Headquarters, opened after the February expiration of the US-Russia New START accord, the last legally binding constraint on strategic warhead deployments, without a successor in place. UN High Representative for Disarmament Affairs Izumi Nakamitsu separately stated that "the threat of nuclear weapons use is becoming more frequent."

Analysis
The February lapse of New START without a successor removed the last binding constraint on US and Russian arsenals at precisely the moment warhead counts turned upward for the first time in decades, creating a structural backdrop the 2015 and 2022 review cycles, both of which collapsed without final documents, did not face. That precedent, corroborated across UN News, Xinhua, and Arab News (though Xinhua's state affiliation inclines its framing toward disarmament rhetoric that flatters Chinese nonproliferation positioning), makes a third consecutive procedural failure by May 22 likely, crossing the threshold from negotiating difficulty into regime dysfunction. The warhead count increase may reflect modernization cycling rather than genuine expansion, in which case the conference faces familiar political deadlock rather than a qualitatively new strategic environment. The more durable risk runs independently of that question: if nuclear-armed states begin treating the testing norm as discretionary, no institutional mechanism currently in force can reverse it without political commitments no actor has offered.

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