Contests of legitimacy and value: the Treaty on the Prohibition of Nuclear Weapons and the logic of prohibition

The recently adopted Treaty on the Prohibition of Nuclear Weapons (TPNW) has caused much debate and controversy in global nuclear politics. Given that the stated goal of the TPNW supporters (states and NGOs alike) is to embed the treaty in the structures of nuclear governance and to strengthen its normative power, how likely is the TPNW to achieve these objectives? The article argues that the unique structures of legitimacy and value within which nuclear weapons are enmeshed place particular complications on the normative force of the TPNW as compared to previous humanitarian arms control initiatives, which has implications for the way in which the TPNW can function to consolidate a prohibitionary norm on nuclear weapons possession. The article uses the framing of legitimacy to analyse the complex structures within which the TPNW was adopted and within which it will enter into force, particularly focusing on the TPNW's relationship to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The article concludes that consolidation may require a further challenge to the existing structures of nuclear order than state actors have, so far, been willing to make. This work is based on first-hand observations from the TPNW negotiations and interviews with civil society actors at the United Nations in New York in June and July 2017.