On 7 July, after a remarkably short negotiating period of about five weeks in New York, participating countries adopted a nuclear ‘Ban Treaty’ (the official title is ‘Treaty on the Prohibition of Nuclear Weapons’) and released the text of the document. The final vote of approval was 122-1 (the lone opposing vote being that of the Netherlands) with one abstention (Singapore). Frustration with the perceived slow pace of the traditional step-by-step approach of the nuclear-weapons states (NWS) and their allies in making progress toward the elimination of nuclear weapons, as promised in Article VI of the Non-Proliferation Treaty (NPT) and elsewhere, led a significant number of non-nuclear-weapons states (NNWS) and non-governmental organisations (NGOs) to undertake the negotiations, which the United Nations General Assembly (UNGA) had authorised in December 2016. About 140 countries participated in the negotiations. While the treaty is an impressive diplomatic achievement, reflecting the views of a solid majority of UN member states, none of the states that actually possess nuclear weapons participated. This leaves a curious legal situation in which the only state parties to the treaty, at least initially, will be those already prohibited from acquiring nuclear weapons by the NPT. In addition, many supporting states, especially in Latin America and Africa, are already in nuclear-weapon-free zones.
The stated purpose of the treaty is to prohibit nuclear weapons. Supporters claim that it will close a ‘legal gap’ and complete a general prohibition of all weapons of mass destruction (WMD), given the 1972 Biological Weapons Convention (BWC) and the 1997 Chemical Weapons Convention (CWC). The Humanitarian Campaign for the Ban Treaty drew inspiration from the 1996 Advisory Opinion of the International Court of Justice, and from new research indicating that the effects of even a relatively small exchange of ‘only’ 100 nuclear weapons between India and Pakistan could produce a ‘nuclear winter’ even worse than previously understood, with catastrophic consequences for world climate and agriculture. The movement gathered momentum with conferences in Norway in 2013 and in Mexico and Austria in 2014, followed by an Open-ended Working Group authorised by the UNGA in 2016, which ultimately urged negotiation of the treaty. The five NWS, coincidentally comprising the five permanent members of the UN Security Council (P5), boycotted all of these forums, except that the United States and the United Kingdom did attend the Austria conference in 2014. It appears unlikely that any members of NATO or other ‘umbrella’ states that depend on extended nuclear deterrence will support the treaty. Early claims that the Ban Treaty will become ‘international law’ binding on all states have been dropped, but some are already characterising any nuclear state that does not join as an ‘outlaw state’.