March 7, 2025
SGS researchers were active participants in the Third Meeting of States Parties (3MSP) of the United Nations Treaty on the Prohibition of Nuclear Weapons (TPNW) which took place from 3 to 7 March 2025 at United Nations Headquarters in New York. The treaty has 94 signatory states and 73 states parties. It entered into force in 2021.
Three researchers affiliated with SGS were at 3MSP as members of the Scientific Advisory Group of the TPNW. The Group is an official body established by TPNW states in 22023. It is the first international scientific body with the mission of advancing nuclear disarmament created by a United Nations treaty process. The three members of SGS appointed to the Scientific Advisory Group are SGS co-director Zia Mian, associate research scholar Sébastien Philippe, and visiting researcher Moritz Kütt. Zia Mian has served as elected co-chair of the Scientific Advisory Group since it was founded and will serve until the 2026 Review conference of the treaty. SGS provides organizational and administrative support for the Group. A dedicated scientific and technical advisory body for the TPNW was first proposed in an article published in 2019 by SGS researchers Tamara Patton, Sébastien Philippe, and Zia Mian.
At 3MSP, Zia Mian was an invited presenter in the plenary debate on the risks to humanity of a nuclear conflict and its devastating humanitarian consequences. The panel was chaired by Melissa Parke, the Executive Director of the International Campaign to Abolish Nuclear Weapons (ICAN), which received the 2017 Nobel Peace Prize for its work on the TPNW.
Mian later presented the work of the Scientific Advisory Group together with co-chair Patricia Lewis, formerly Research Director for International Security at Chatham House and Director of the United Nations Institute for Disarmament Research (UNIDIR). For 3MSP, the Scientific Advisory Group (SAG) prepared a Working Paper on the status and developments regarding nuclear weapons, nuclear weapon risks, the humanitarian consequences of nuclear weapons, nuclear disarmament and related issues. This working paper updates the SAG report to 2MSP in November-December 2023.
SGS also sponsored an expert panel side event at 3MSP on March 4, 2025. The panel included Zia Mian, Moritz Kütt, and SGS research collaborator Tamara Patton, Nick Ritchie of the University of York, and Patricia Lewis.
The event focused on the elimination of nuclear-weapon programs under Article 4 of the TPNW. Article 4 requires nuclear-armed states who join to verifiably eliminate their nuclear-weapon programs, including the elimination or irreversible conversion of all nuclear-weapons-related facilities. These states also must conclude safeguards agreements with the International Atomic Energy Agency. The panel presentations focused on how to define and characterize a nuclear weapon programme, verification, and irreversibility of elimination.
The panel aimed to support and inform ongoing discussions among states and the work of the Scientific Advisory Group related to Article 4 implementation. SGS has supported the TPNW process since before the treaty was agreed in 2017, including through an informal Ban Treaty Study Group of experts, officials and activists dedicated to the treaty.