Transitioning from the Nuclear Non-Proliferation Regime to a Future Global Nuclear-Zero Regime: What Legal and Institutional Issues Will the TPNW Need to Address Going Forward?

Achieving a world without nuclear weapons requires a transition from today’s nuclear non-proliferation regime to a durable nuclear-zero regime. Separating (i) legal and institutional functions of a legal framework from (ii) enabling conditions beyond treaty design, including cooperative geopolitics and conflict mitigation, this article critically evaluates to what extent the Treaty on the Prohibition of Nuclear Weapons (TPNW) provides, or could evolve to provide, legal and institutional functions required for a future durable global nuclear-zero regime, constructively identifying issues to be addressed going forward. It finds that, while the TPNW powerfully codifies the delegitimization and comprehensive prohibition of nuclear weapons, important legal and institutional design gaps remain. On the legal aspect, the treaty does not prohibit production of fissile material, is silent on delivery systems, and affirms an inalienable right to peaceful nuclear activities without reservation. Institutionally, its verification provisions are underspecified (both for nuclear-armed states and for non-nuclear-weapon states), no enforcement architecture is provided, and withdrawal rules may be too permissive and, in some scenarios, destabilizing. The article concludes with an agenda for treaty operation and reform to bridge the gap between normative movement and required legal and institutional functions.