READ FULL REPORT Nuclear norms face significant challenges, highlighted by Russia’s withdrawal of its ratification of the Comprehensive Nuclear-Test-Ban Treaty and the general undermining of nuclear institutions. This report assesses the health of three key nuclear norms: nonproliferation, nonuse, and no testing, revealing that while these norms are broadly supported, they are increasingly contested. The interconnectedness of these norms means that weakening one could trigger a cascade effect, jeopardizing the others. The report identifies regional dynamics and differing responses to norm violations as key factors exacerbating this contestation. The policy recommendations include, for example, a reinforcement of the three norms through transparency and restraint by nuclear possessors and an engagement of non-nuclear states and civil society in norm enforcement and pressure on norm violators. This report is made possible with support from the British Embassy Washington.