The American authorities dislike the word “assassination”, because it implies a flouting of international and humanitarian law. Indeed, some human-rights lawyers see the use of drones to kill people as almost always unlawful. Agnès Callamard, the UN’s special rapporteur on extrajudicial, summary or arbitrary executions, has argued that “outside the context of active hostilities, the use of drones for targeted killing is almost never likely to be legal….lethal force can only be used where strictly necessary to protect against an imminent threat.”