Preventive Killings: The Reconceptualization of the Use of Force in Individual and Unit “Self-Defense” Reactions

This chapter explores the reconceptualization of individual and unit preventive self-defense in combat operations. The chapter, divided into three sections, first explores how successive US administrations adopted a new concept of an imminent threat and thus significantly changed how lethal force was used in preventive self-defense reactions. The first section shows how the US embraced a redefinition of an imminent threat that abandoned one of its key traditional elements—that is, the immediacy of the threat. The second section examines how the US military used the new definition of an imminent threat to relax the rules on preventive “self-defense” in combat operations. By examining cases of the preventive use of force, the chapter explores in which situations US troops were allowed to use force preventively (e.g., when seeing an individual talking on a phone in the vicinity of US troops; when seeing an individual digging into the ground; when seeing an individual fleeing from the site of a military attack). This section shows how the new understanding of an imminent threat enabled US troops to rely on very broad threat categorizations that blurred the line between civilians and legitimate military targets. The third section provides insights into how the new conceptualization of individual or unit preventive self-defense created the circumstances for violations of key principles of international humanitarian law, that is, the principles of distinction, necessity, and proportionality.