Targeted killing has become part of the conventional military and security strategy of a number of states in their operations against terrorist suspects, with Israel, the US and Russia among the most notable that have openly employed such tactics. Controversy has arisen regarding whether, as the perpetrator states have asserted, such killings should be considered as part of an ongoing ‘war’ against terrorist organizations, thus judged according to the law on the use of force (jus ad bellum) and the law of armed conflict (jus in bello or international humanitarian law (IHL), or whether the struggle against terrorist groups should be considered within a law enforcement framework, thus engaging international human rights law (IHRL). This chapter examines these issues.