--- title: "Treaty on the Prohibition of Nuclear Weapons (TPNW)" description: "The TPNW is the 2017 treaty that outright bans nuclear weapons, entering force in 2021. See how it differs from the NPT and why nuclear states reject it." url: "https://modeldiplomat.com/learn/glossary/treaty-on-prohibition-of-nuclear-weapons" --- [New](https://modeldiplomat.com/) # Model Diplomat Research Team · Last reviewed June 22, 2026 TL;DR - The TPNW is a 2017 multilateral treaty that comprehensively prohibits the development, possession, use, and threat of use of nuclear weapons. - Why have no nuclear-armed states joined the TPNW? - How does the TPNW differ from the NPT? - What is India's position on the TPNW? - When did the TPNW enter into force? [Civil Service & Diplomatic Exams](https://modeldiplomat.com/learn/civil-services/glossary)Updated June 22, 2026 The TPNW is a 2017 multilateral treaty that comprehensively prohibits the development, possession, use, and threat of use of nuclear weapons. Go beyond the definition ## Research Treaty on the Prohibition of Nuclear Weapons (TPNW) like a delegate Model Diplomat's AI drafts position papers, speeches, and country research with real sources — built for MUN and politics students. ## Timeline 1. 7 July 2017 The Treaty on the Prohibition of Nuclear Weapons (TPNW) was adopted by 122 states at the United Nations on , following a negotiating mandate established by U… 2. 23 December 2016 The Treaty on the Prohibition of Nuclear Weapons (TPNW) was adopted by 122 states at the United Nations on 7 July 2017, following a negotiating mandate estab… 3. 20 September 2017 The TPNW opened for signature on and entered into force on 22 January 2021, ninety days after Honduras deposited the fiftieth instrument of ratification as… 4. 22 January 2021 The TPNW opened for signature on 20 September 2017 and entered into force on , ninety days after Honduras deposited the fiftieth instrument of ratification a… ## Positions at a glance ### Supporters Controversy centers on the treaty's verification provisions, which critics characterize as weaker than the IAEA Additional Protocol that several nuclear-capable states have not universally adopted. The five permanent members of the UN Security Council issued a joint statement in 2018 reaffirming opposition, and a January 2022 P5 statement on preventing nuclear war pointedly avoided endorsing the TPNW. Supporters counter that the treaty's value is normative — stigmatizing nuclear weapons and shifting the legal and moral baseline much as the conventions banning chemical weapons, landmines, and cluster munitions did before universal adherence. The accession of states hosting allied nuclear weapons under NATO arrangements, and the participation of NATO members such as Germany and Norway as observers at the First Meeting of States Parties, signal contested terrain within the alliance. ### Opponents The TPNW is best understood in contrast to the Nuclear Non-Proliferation Treaty (NPT) of 1968, which it does not replace. The NPT is a grand bargain: non-nuclear states forgo weapons in exchange for access to peaceful nuclear energy and a commitment by the five recognized nuclear-weapon states to pursue disarmament under Article VI. The TPNW imposes a flat prohibition on all parties and contains no peaceful-use bargain because its members already eschew weapons. It also differs from the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which bans only testing and has not entered into force, and from regional nuclear-weapon-free zone treaties such as Tlatelolco and Pelindaba, which are geographically bounded. Critics within the NPT framework, including the United States, argue the TPNW risks undermining the NPT's consensus-based regime and the safeguards architecture of the International Atomic Energy Agency. ## Research it like a delegate Research on modeldiplomat.com ## Ask a follow-up about Treaty on the Prohibition of Nuclear Weapons (TPNW) Open a cited briefing in Model Diplomat search — timelines, positions, and sources you can use in committee or exam answers. [Start research on Treaty on the Prohibition of Nuclear Weapons (TPNW)](https://modeldiplomat.com/search?q=Explain%20Treaty%20on%20the%20Prohibition%20of%20Nuclear%20Weapons%20\(TPNW\)%20%E2%80%94%20key%20dates%2C%20actors%2C%20positions%2C%20and%20sources) Example In June 2022, Germany and Norway — both NATO members reliant on US nuclear deterrence — attended the TPNW's First Meeting of States Parties in Vienna as observers, signalling intra-alliance debate despite refusing to ratify. 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