Dialogue to Strengthen the Outer Space Treaty and Deter the Placement of Nuclear Weapons in Outer Space

Geneva, Switzerland
May 26–27, 2026

Secure World Foundation (SWF), in partnership with the Council on Strategic Risks (CSR) and the Geneva Centre for Security Policy (GCSP), is pleased to co-organize the “Dialogue to Strengthen the Outer Space Treaty and Deter the Placement of Nuclear Weapons in Outer Space,” a two-day, not for attribution discussion aimed at reinforcing legally-binding restrictions against the deployment and use of nuclear weapons in outer space. 

Despite being in force for 59 years and having 118 state parties, the Outer Space Treaty (OST) faces growing strain amid an increase in reckless behavior by multiple nuclear-armed states. As commercial, governmental, and scientific reliance on space-based capabilities continues to expand, the ability to verify compliance with the OST has become more critical than ever. Failure to uphold the Treaty’s prohibition on nuclear weapons in space risks degrading the space environment as a vital domain for economic activity and global communications, and in the most severe scenarios, could contribute to nuclear escalation across domains.

The “Dialogue to Strengthen the Outer Space Treaty and Deter the Placement of Nuclear Weapons in Outer Space” seeks to raise global awareness of the urgent and unique risks posed by the deployment of nuclear weapons in space, while underscoring their illegality under the OST. 

SWF, CSR, and GSCP will bring together international experts to assess current OST verification capabilities and challenges, with the goal of strengthening implementation of Treaty obligations and identifying innovative pathways for international engagement to deter future violations By helping bridge technical, legal, and diplomatic communities, this dialogue aims to ensure that efforts to deter the placement of nuclear weapons in outer space are inclusive, credible, and consider both strategic stability and technical viability issues.

The initiative is supported by the Carnegie Corporation of New York and Longview Philanthropy through the Consortium to Reduce Nuclear Dangers.

Participation in this event is by invitation only; a report capturing the key discussion points will be released to the public after the event.

For more information, please contact SWF Chief Director, Space Security and Stability, Victoria Samson.