PREPARATIONS are already underway at the United Nations for the 2026 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which was originally signed in 1968.

Many expect a contentious event. Some countries are having second thoughts about the principle of non-proliferation, because they wonder if Russia would have invaded Ukraine in 2022 if the latter had kept the nuclear weapons it inherited from the Soviet Union. Such counterfactuals, in turn, have renewed others’ fears of nuclear proliferation.

These concerns are not new, of course. In my memoir, A Life in the American Century, I revisit an equally contentious period in the 1970s, when I was in charge of US president Jimmy Carter’s non-proliferation policy.