Chapter 8 seeks to untangle various issues in addressing when and how a state might be able to resort to the use of force in self-defence against non-state actors. It firstly raises some important general considerations in relation to self-defence against non-state actors, before moving on to examine the situation of self-defence measures which target both the non-state actors and the host state, as was the case with the United States’s response to the terrorist attacks of 11 September 2001. A distinction needs to be made between self-defence taken against both the non-state actor perpetrators of the attack or those posing a threat and the state within which they are located, and those actions that are more limited in only specifically targeting the non-state actors. The chapter finally addresses the particular phenomenon of so-called targeted killing, which engages not only the jus ad bellum, but also the legal framework of international human rights law and, potentially, international humanitarian law.

Before developing the argument of the book, this chapter gives an overview of the contexts where combat drones have been deployed as a basis for the study. The description of the contexts in which drone operations have been conducted extraterritorially against non-state actors by the US, the UK, and France follow a chronological sequence, and draw some general common and diverging features of the different legal rationales crafted by these states.

The goal of detecting future events has several implications and two of them are explored in this chapter. First, the objective of detecting future events means that whoever poses a threat has to be targeted and if the threat is posed by a number of individuals that increases over time, enmity is extended to those individuals. This is true even if they act in the name of a terrorist group that did not exist when the conflict started. From a legal perspective, this practice is facilitated by the uncertainties related to the temporal delineation of conflicts. Second, the objective of addressing future threats entails to act against individuals who are not presently perpetrating hostile acts. This practice requires that the traditional interpretation of direct participation in hostilities be subjected to a temporal change. Instead of suspending the protection of civilians solely when ‒ and only for such time as ‒ they engage in acts that reach a certain threshold of harm, targeting enemies because of the threat they pose for the future means extending direct participation in hostilities not only to preparatory acts, but also to signs revealing membership to an enemy group. This shift is facilitated by the insufficiently defined notion of “continuous combat function.”

The chapter describes David Kretzmer as a role model for a world-renowned expert: the exceptional breadth of his expertise, the razor-sharpness of his inquiries, his ability to differentiate between law and politics in sensitive issues, his courage to deal critically with ‘the embarrassing’, his exemplary teaching, his impeccable intellectual integrity, his activism in protecting human rights and his modesty. The article briefly describes Kretzmer’s contributions on several issues: the legal status of the Israeli Arab-Palestinian citizens, the Israeli belligerent occupation and counter-terrorism measures like deportations, house demolitions and targeted killings, judicial activism and other trends (both transparent and hidden) in the Israeli case law, and racial incitement as a criminal offense. It exemplifies Kretzmer’s impact on the Israeli Supreme Court.