Nuclear Threats and the (F)Utility of Law

International law seeks to establish rules, treaties, and agreements to constrain the use of nuclear weapons by states. Nuclear deterrence, by contrast, is a theory that relies on nuclear threats by political leaders to prevent nuclear weapons use and avoid nuclear war. Both approaches depend upon norms and customary practices that restrain nuclear weapons use even in times of crisis. However, recent nuclear threats by Russia in the war in Ukraine; US and Russian withdrawals from major arms control treaties; the fraying of the international nuclear nonproliferation regime; unregulated technological innovation; and a new arms race among the United States, Russia, and China are testing the norms and practices of nuclear nonuse and contribute to the most dangerous period since the first years of the nuclear age. This article reviews the utility, in turn, of law, deterrence, and norm-building, and concludes that no one approach promises adequate protection from nuclear catastrophe.