Britain’s decision to leave the EU has been labelled an ‘exceptional act of self-harm’. But is it? In October South Africa became the first country to announce its formal withdrawal from the International Criminal Court (ICC). This was soon followed by the exit of Burundi and Gambia and by Russia’s announcement that it intends to withdraw from the Rome Statute which establishes the ICC. Although the Court has been hampered since its inception by the refusal of major states such as the US, China and Russia to submit to its jurisdiction, these withdrawals represent an unprecedented challenge to its legitimacy. Things look no brighter in the area of international security cooperation, as illustrated by the slow acceptance of Additional Protocol safeguards under the NPT and the failure of Annex 2 countries to ratify the Comprehensive Treat Ban Treaty. Even longstanding alliances seem at risk of unravelling. In June Uzbekistan announced its (re-)exit from the Collective Security Treaty Organization, and NATO leaders are growing increasingly nervous that the Trump Administration will turn its back on America’s allies. Meanwhile, there is a growing trend towards withdrawal from and denunciation of international human rights treaties, the G8 has shrunk to the G7, and the use of UNSC vetoes—which were at a historic low during the 1990s—is once again on the rise.