Targeted killing of suspected terrorists: Extra-judicial executions or legitimate means of defence?

Whether a state that has been subject to attacks by a transnational terrorist group may target active members of that group who are not in its jurisdiction has caused controversy. Some refer to targeted killings of suspected terrorists as extra-judicial executions; others claim they are legitimate acts of war. The author examines the legality of such killings under norms of international human rights law and international humanitarian law. Under the former system, such killings can only be lawful when carried out to prevent an imminent attack that cannot be stopped by other means. Under the latter system, such killings may be lawful if the suspected terrorists are to be regarded as combatants. He argues that while in international armed conflicts suspected terrorists are generally not combatants, in non-international armed conflicts they may well be combatants. In such conflicts norms of international humanitarian law cannot stand on their own; the applicable system must be a mixed model, which incorporates features of international human rights law. In the final section the author discusses the Israeli policy of targeted killings and the US attack on suspected members of al-Qaeda in Yemen, and applies the mixed model to these cases.