Switzerland
In March 2024, Switzerland’s Federal Council decided that ‘Switzerland will not join the [Treaty on the Prohibition of Nuclear Weapons (TPNW)] for the time being’ based on factors including ‘recent security policy developments in Europe and globally’. It reached similar decisions in 2018 and 2019. The Council said that it was ‘convinced that joining the TPNW is not in Switzerland’s interests, given the current international context and the war in Europe, which have highlighted the renewed urgency of security considerations’.1
TPNW Status
| Key weapons of mass destruction treaties | ||
|---|---|---|
| NUCLEAR WEAPONS | ||
| Party to the TPNW | No | |
| Party to the NPT | Yes (Ratified 1977) | |
| Ratified the CTBT | Yes (Ratified 1999, Annex 2 state) | |
| Party to an NWFZ | No | |
| CSA with the IAEA | Yes (In force 1978) | |
| AP with the IAEA | Yes (In force 2005) | |
| BIOLOGICAL AND CHEMICAL WEAPONS | ||
| Party to the BWC | Yes (Ratified 1976) | |
| Party to the CWC | Yes (Ratified 1995) | |
| TPNW Art. 1(1) prohibitions: Compatibility in 2025 | ||
|---|---|---|
| (a) | Develop, produce, manufacture, acquire | Compatible |
| Possess or stockpile | Compatible | |
| Test | Compatible | |
| (b) | Transfer | Compatible |
| (c) | Receive transfer or control | Compatible |
| (d) | Use | Compatible |
| Threaten to use | Compatible | |
| (e) | Assist, encourage or induce | Compatible |
| (f) | Seek or receive assistance | Compatible |
| (g) | Allow stationing, installation, deployment | Compatible |
| TPNW voting and participation | |
|---|---|
| UNGA resolution on TPNW (latest vote) | Abstained (2025) |
| Participated in 3MSP (2025) | Yes (observer) |
| Participated in 2MSP (2023) | Yes (observer) |
| Participated in 1MSP (2022) | Yes (observer) |
| Average MSP delegation size (% women) | 2.67 (17%) |
| Adoption of TPNW (7 July 2017) | Voted yes |
| Participated in TPNW negotiations (2017) | Yes |
| Negotiation mandate (A/RES/71/258) | Abstained |
| Fissile material | |
|---|---|
| Nuclear facilities | Yes |
| Fissile material production | No |
| HEU stocks | Cleared |
| Plutonium stocks | Stored abroad |
| SQP with the IAEA | No |
Latest developments
In response to the Swiss Federal Council’s decision in 2024 not to join the Treaty on the Prohibition of Nuclear Weapons (TPNW) ‘for the time being’, several non-governmental organizations based in Switzerland, including the International Campaign to Abolish Nuclear Weapons (ICAN), launched a popular initiative aimed at securing Switzerland’s accession to the Treaty.2
In December 2025, more than 100,000 valid signatures were submitted to the relevant authorities in Switzerland, triggering a national political process asking Switzerland to sign and ratify the TPNW. If the government refuses to do so, the matter will be put to the Swiss people in a public referendum. ‘This achievement demonstrates what many in Switzerland and abroad already understand. Public support for the TPNW is broad, deeply rooted, and cuts across political lines,’ said ICAN in a statement.3
Switzerland attended the Third Meeting of States Parties (3MSP) to the TPNW in March 2025 as an observer. ‘This participation is motivated by the fact that we share the humanitarian and disarmament objectives of the Treaty and we deem it important to engage in a constructive dialogue with the Treaty and its stakeholders,’ it said, while noting its decision in 2024 ‘not to join the TPNW for the time being’. It expressed hope that the TPNW would contribute effectively to the implementation of Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).4
At the NPT Preparatory Committee meeting in April 2025, Switzerland said warned that the ‘nuclear arms control and disarmament architecture remains under constant stress’ and ‘we observe worrying signs of increasing reliance on nuclear weapons in military doctrines and national security strategies in all nuclear-weapon States and beyond’.5
In the First Committee of the UN General Assembly in October 2025, Switzerland said: ‘The rest of this decade could very well be decisive for nuclear disarmament and non-proliferation. In particular, we must prevent a slide back into a nuclear arms race that could spiral out of control.’6
Recommendations
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Switzerland should urgently adhere to the TPNW. Until it is in a position to do so, it should welcome the TPNW as a valuable component in the global disarmament and non-proliferation architecture, work with the Treaty's states parties on practical steps towards disarmament, and attend the meetings of states parties as an observer.