The war against vague threats: The redefinitions of imminent threat and anticipatory use of force

This article explores how the United States (US) has redefined the concept of ‘imminent threat’ in order to relax the rules for anticipatory use of armed force against insurgents. The article focuses on how two new definitions of imminent threat have changed the conduct of specific combat activities, namely, drone strikes and ground combat operations. The central part of the article is divided into four sections. The first section examines the redefinition of imminent threat in the context of drone warfare, while the second section provides an analysis of the redefinition of imminent threat in ground combat operations. Both sections show how the new definitions of imminent threat abandoned two key elements of the classic definition, that is, the immediacy and certainty of the threat. The third and fourth sections of the article explore how the new definitions of imminent threat prevented the application of two key principles governing the use of armed force: the principles of necessity and proportionality. Both sections show how successive US administrations enabled the US military to conduct operations without observing these two key principles regulating the use of force.