The Treaty on the Non-Proliferation of Nuclear Weapons has served as the normative anchor of global nuclear orders since 1968. Remarkably successful with respect to peaceful uses of nuclear energy and non-proliferation, it has failed to achieve nuclear disarmament. In 2017, geopolitical tensions had intensified in several regions across the world; there were no nuclear arms control negotiations between any of the nuclear-armed states and two of the leaders of countries with nuclear weapons appeared volatile and unpredictable. With fewer warheads but spread amongst more countries, some in conflict-prone regions, nuclear risks and threats have grown, as has the realisation that the world lacks the capacity to cope with the humanitarian consequences of nuclear war. Like-minded states and civil society advocates teamed up to heighten the consciousness of nuclear dangers and convened a United Nations-mandated conference to negotiate a prohibition treaty adopted on 7 July. In the ensuing bifurcated global nuclear order, it has become necessary to reconcile latent tensions between the two nuclear regimes, for example with regard to safeguards standards, institutional linkages, and enforcement agencies.