Why do states commit to the Treaty on the Prohibition of Nuclear Weapons?

Abstract

ABSTRACT On January 22, 2021, the Treaty on the Prohibition of Nuclear Weapons (TPNW) entered into force. The aim of the treaty is to delegitimize nuclear weapons by strengthening the antinuclear norm. The aim comes with the expectation that this will gradually contribute to an environment in which nuclear weapons can be eliminated because they are unacceptable instruments of statecraft. However, the effectiveness of antinuclear norms has been contested in discussions around the TPNW. In particular, the question of how norms operate within smaller identity communities has attracted the attention of scholars studying commitment to international treaties. By using a mixed-methods research design, this article adds to the ongoing discussion by exploring the conditions under which regional normative pressure can explain commitment to the TPNW. Statistical analyses show that regional normative pressure significantly increases the likelihood of commitment. Further analyses, using qualitative comparative analysis, indicate that this pressure is effective only toward states with previous nonproliferation commitments and where commitment to the TPNW does not entail a perceived weakening of national security. Thus, in the context of disarmament, normative pressure is trumped by security concerns.