This chapter is concerned with exploring the mutually constitutive character of the international law of nuclear weapons, and the Cold War and post–Cold War environs in which that law was to be developed. In one direction it is argued that a consensual treaty-based system of law-making prevailed during the Cold War, which shifted to a system of Security Council legislation in the post-Cold War era, and that this reflected a parallel shift from a multipolar to a unipolar geopolitics. In another direction, however, it is also argued that the international law of nuclear weaponry also contributed to the production of its own political environs by both legitimating the possession of nuclear weaponry and controlling its spread.

The fall of the Berlin Wall in 1989 and the collapse of the Soviet Union in the years which followed brought into play a new international imaginary launched with a flurry of inaugural gestures. These included the proclamation, by US President George Bush, of a ‘New World Order’ in 1991, the publication, by UN Secretary-General Boutros Boutros-Ghali, of an Agenda for Peace in 1992,and, in the most triumphalist gesture of the three, the American political scientist Francis Fukuyama’s invocation of the end of history. Many international legal scholars, too, applauded the beginning of a new post–Cold War world, no longer dominated by two rival superpowers. It was a moment widely thought to be full of new ‘global’, if not cosmopolitan, possibilities.