Are our red lines just marvelous fiction? Determining limits to outsourcing during armed conflicts (Frauke Renz)

International humanitarian law (IHL) prohibits the outsourcing of only a few functions to private contractors, such as the administration of prisoner of war camps. For other roles, no explicit prohibitions exist. This becomes especially relevant when assessing new trends in warfare such as the operation of armed drones and the programming of increasingly autonomous weapon systems. Yet, this article argues that there are limits based on the fundamental principles of IHL. Contracting states cannot uphold the principle of distinction in good faith while relying on private contractors to directly participate in hostilities on a regular basis. This holds true even if the contractors are considered civilians based on contractual agreement. To uphold the principle of distinction, states should not outsource the widespread and regular direct participation in hostilities, especially if the acts are carried out in proximity to the battlefield.