UN Charter Article 51

Article 51 is UN Charter provision preserving the inherent right of individual or collective self-defence against armed attack. Article 51 of the UN Charter, adopted in 1945, preserves the inherent right of individual or collective self-defence if an armed attack occurs against a UN member, until the Security Council acts. It is the Charter's only explicit exception to the requirement for Security Council authorisation before the use of force, and it has anchored major self-defence claims since 1945, including the US invocation for Afghanistan in 2001, France's after the 2015

Bataclan attacks, and the UK's for strikes against ISIS in Syria the same year. Whether the article covers attacks by non-state proxies attributed to a state remains contested in international law. The 2026 Iran war has produced more Article 51 invocations in a few months than most conflicts generate in years, each hinging on the same disputed question: how solid the evidence of an armed attack needs to be before the right to respond attaches. The 29 July Iraq strike, resting on intercepted rather than landed drones, pushes that threshold further than any of the earlier Gulf invocations.