When May UN Peacekeepers Use Lethal Force to Protect Civilians? Reconciling Threats to Civilians, Imminence, and the Right to Life

Abstract While the use of force in UN peacekeeping was traditionally limited to self-defence, the UN Security Council now regularly deploys peacekeeping missions with robust mandates to protect civilians and encourages their proactive implementation, including by using force. For many years, the Security Council authorised the use of ‘all necessary means’ to protect civilians from ‘imminent threats’ of physical violence, but its recent mandates have often dropped references to ‘imminence’. The UN has also interpreted such mandates as broader authorisation for peacekeepers to use force in response to temporally ill-defined threats to civilians. This turn to robust civilian protection is often celebrated, yet the legal parameters of using force continue to evolve below the radar and are rarely scrutinised, with scholarly writing focused on peacekeeper self-defence, rules of engagement and UN policy to justify proactive mandate implementation. Drawing on an analysis of the relationship between peacekeeping mandates and international law in light of the shift from defensive to proactive peacekeeping, this article argues that the legality of using force for civilian protection purposes must be reconciled not only with Security Council resolutions and their language on imminence, but also with human rights law (HRL), which imposes strict temporal conditions for lawful deprivations of the right to life outside the conduct of hostilities. Using examples of how the UN’s current practice of using force to protect civilians in hostile environments may contravene international norms, this article attempts to reconcile proactive civilian-oriented peacekeeping with the concept of imminence as understood in HRL.