Self-Defence

Abstract

Abstract A State may exercise its inherent right of individual self-defence against any activity, including an action from, to, or within space, that constitutes an armed attack, and its right of anticipatory self-defence against any activity that amounts to an imminent armed attack against it. Article 51 of the UN Charter recognizes the inherent right of individual or collective self-defence if an armed attack occurs against a UN member. The UN Charter and international law are explicitly made applicable to the exploration and use of outer space, including the Moon and other celestial bodies, by the Outer Space Treaty (OST). Article 51 also reflects customary international law. The exercise of the right of self-defence must also conform to the requirements of necessity and proportionality. An armed attack under this rule includes an imminent armed attack. Any exercise of self-defence remains subject to all the requirements set forth in Article 51 and remains subject to the primacy of any effective measures that may be imposed by the UN Security Council.