Self-Defence as a Justification for UAV Strikes Overseas: The Legality of the Use of Force in Response to Terrorist Threats

It is the long-held position of the United Kingdom that targeted killings are contrary to international law, a position consonant with the pronouncements of the United Nations Security Council. The Government should clarify whether it has departed from this view and, if so, its reasons for so doing; 2. There is a strong presumption in international law that a use of force is unlawful. It is for the State which claims a justification for its use of force (such as self-defence) to demonstrate that its action was a valid application of that justification. In so doing it must meet a high standard of proof; 3. International law permits action to be taken in self-defence against an armed attack which has occurred or which is imminent only, and not in relation to attacks that are merely threatened; 4. Whether non-state actors can launch armed attacks for the purposes of Article 51 of the UN Charter is highly disputed; 5. In order to qualify as an armed attack for the purpose of self-defence, an attack must have a transboundary quality. The attacker must strike at the State from outside. That a perpetrator is aligned with a terrorist organisation overseas will not, without more, result in a right to take action in self-defence against that organisation; 6. The position of the United Kingdom and of the Government on the status of the “unwilling or unable” doctrine requires clarification, as does the Government’s opinion on the doctrine’s applicability in Syria; 7. Nevertheless, it is unlikely that the “unwilling or unable” doctrine has crystallised as a rule of customary international law; 8. The United Kingdom must demonstrate that any action taken in pursuance of self-defence is both necessary and proportionate and, in particular, that no non-forcible alternative course of action exists in any given instance, and that the urgency of taking action in any instance prevents recourse to the Security Council.This report was commisioned by Joint Select Committee on Human Right