The jus ad bellum/jus in bello distinction and the law of occupation

This is a preliminary inquiry into the application to occupation law of the distinction between jus in bello (or IHL) and jus ad bellum. Under current doctrine, the two are mutually exclusive: the former applies irrespective of the “nature or origin of the armed conflict or the causes espoused by the Parties.” I argue that occupation law, although generally considered part of IHL, is intrinsically less susceptible to a strict application of the distinction. Exploring its pedigree, meaning, and rationale, the paper notes the distinction's scant, soft Conventional expression and brief history, but also its fundamental character and the broad scope attributed to it under contemporary IHL. Although the distinction sometimes fulfill important humanitarian functions in occupied territories, occupation law—in regulating governance of territory—differs from ordinary IHL norms; this and other differences render the strict application of the distinction to occupation law, whose key norms often depend on jus ad bellum references to the “nature, origin and causes” of armed conflict, impossible. The last part of the Paper calls for a more nuanced approach to the application of the distinction to occupation law and identifies some of its contours. Such an approach can enhance the efficacy of occupation law and facilitate fulfillment of the two different functions of occupation law: protection of individuals and the maintenance of international peace and security. The Paper concludes with preliminary observations on the roles and powers, under both jus ad bellum and jus in bello, of the Security Council with regard to occupied territories.