Universalization refers to the ongoing campaign by states parties, civil society, and the International Campaign to Abolish Nuclear Weapons (ICAN) to grow the Treaty on the Prohibition of Nuclear Weapons (TPNW) from its current membership toward universal participation. The TPNW was adopted at the United Nations on 7 July 2017, opened for signature on 20 September 2017, and entered into force on 22 January 2021 after reaching 50 ratifications.
The treaty bans developing, testing, producing, acquiring, possessing, stockpiling, transferring, using, or threatening to use nuclear weapons, as well as assisting such activities. Universalization is explicitly built into the treaty's architecture: Article 12 obligates each state party to "encourage States not party to this Treaty to sign, ratify, accept, approve or accede to the Treaty, with the goal of universal adherence."
Practical universalization work includes:
- Diplomatic outreach by states parties such as Austria, Ireland, Mexico, New Zealand, and South Africa to non-signatories.
- Meetings of States Parties (MSP), the first of which was held in Vienna in June 2022 and the second in New York in November–December 2023, both of which adopted action plans containing universalization measures.
- Civil society advocacy, notably ICAN's parliamentary pledge campaign and city appeals encouraging municipal governments to call on their national capitals to join.
- Engagement with umbrella-state allies of nuclear-armed powers (e.g., NATO members, Japan, Australia, South Korea), several of which have attended MSPs as observers despite not joining.
The principal obstacles are the non-participation of all nine nuclear-armed states and the reliance of many U.S. allies on extended nuclear deterrence, which they argue is incompatible with TPNW obligations. Proponents counter that universalization is a long-term normative project, comparable to the trajectories of the Mine Ban Treaty (1997) and the Convention on Cluster Munitions (2008), where stigmatization preceded broader accession.
Example
At the Second Meeting of States Parties in New York in late 2023, Austria and Mexico led discussions on a universalization action plan, while Germany, Norway, and Australia attended as observers without joining the treaty.
Frequently asked questions
Membership grows over time; as of the Second Meeting of States Parties in 2023 there were roughly 70 states parties and around 90 signatories. Delegates should check the UN Office for Disarmament Affairs treaty database for the current count.
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