The Prevention of an Arms Race in Outer Space (PAROS) is a concept and a long-standing multilateral disarmament agenda item within the United Nations, aiming to safeguard outer space for peaceful purposes. It was first identified as a priority during the First Special Session of the United Nations General Assembly on Disarmament (SSOD-I, 1978). The core problem it addresses is the potential for a military competition in space, as the foundational 1967 Outer Space Treaty (OST) only prohibits the placement of nuclear weapons or other weapons of mass destruction in orbit, leaving a legal gap regarding conventional weapons.
PAROS functions primarily through the Conference on Disarmament (CD), where it is one of the seven standing items, and through annual UN General Assembly resolutions adopted since 1981. The mechanism involves two main approaches: the negotiation of a legally binding instrument, such as the proposed Draft Treaty on Prevention of the Placement of Weapons in Outer Space (PPWT) advocated by Russia and China, and the promotion of non-binding Transparency and Confidence-Building Measures (TCBMs).
The concept connects directly to the 1967 Outer Space Treaty and related initiatives like the European Union's Draft International Code of Conduct for Outer Space Activities. Recently, the PAROS process has seen significant activity, including a second Group of Governmental Experts (GGE) that operated in 2023–2024 and adopted a consensus report in August 2024. Furthermore, the General Assembly adopted decision 79/512 in December 2024, establishing a new Open-ended Working Group for the period 2025–2028, which replaced previous working groups. This recent shift emphasizes developing norms and principles of responsible behaviour in space, alongside the ongoing push for a comprehensive, legally binding treaty.