Interceptive Self-Defence - When the Trigger Has Been Pulled

Abstract: In a world labouring under the perceived threats of rogue states, international terrorism and weapons of mass destruction, opinions are frequently uttered about the expansion of the right to take military action in order eliminate these threats. The UN Charter prohibits the use of force by states with only two exceptions: authorization by the Security Council and self-defence. The great disagreement on the definition and delimitation of self-defence, codified in article 51 of the UN Charter has lead to widely differing views on the subject. On the one hand, there is the preventive self-defence doctrine as proposed by the United States of America, and on the other, a very literal approach that would require a state to remain a 'sitting duck', waiting for an attack to impact before attempting to respond. When faced with the massive destructive power of today's weapons, waiting is not an option. Article 51 gives a state a right to use force to respond against an aggressive state ''if an armed attack occurs''. Interceptive self-defence stands for the interception of an armed attack before it impacts. It is legal, according to Professor Yoram Dinstein, because it is a response to an armed attack that is in progress, i.e. when the trigger has been pulled. It stands to reason that an armed attack has begun at some point before it impacts. The real question is when has an armed attack begun? Dinstein's asserts that when a state has ''committed itself to an armed attack in an ostensibly irrevocable way'' the target state has the right to resort to forceful measures to defend itself. Examples of interceptive self-defence would be responding to a missile in flight or bombing a fleet en route towards it target. In theory, interceptive self-defence poses no objections but in practice, it seems there are some contradictions. An armed attack is clearly underway when a missile is in flight, but when a fleet is on the high seas, no matter its intentions, it would be to stretch the concept to claim that an armed attack had begun. Neither the aggressive state's intention, nor its preparatory steps taken, is decisive. If there is still time to settle the conflict peacefully, which is the purpose of the prohibition of force, an armed attack has not yet begun. State practice shines little light on the subject. In some cases it seems states are ready to accept self-defence if the armed attack is imminent, but so far no armed attack has been found to be imminent. The answer to when an armed attack has begun lies in the combination of treaty law and customary law. Article 51 requires an armed attack, and customary international law in the form of the Caroline case, which is still applicable, can be used to determine when it has begun, i.e. when it is ''overwhelming, leaving no choice of means, and no moment for deliberation''. When waiting for the aggressor's next step would mean accepting the blow, regardless of it being the sinking of a ship or a nuclear explosion, an armed attack has begun.