Learning to Fight Together: UN Peacekeeping Coalitions and Civilian Protection

Since the end of the Cold War, the United Nations has increasingly used peacekeeping operations (PKOs) to manage crises between and within states. The mandates of contemporary PKOs are demanding, calling on peacekeeping personnel to separate belligerent parties, enforce ceasefire agreements, and protect the physical security of civilians. The pursuit of these distinct objectives presents a unique challenge for the UN because it relies on member states to volunteer personnel for these missions. Therefore, the achievement of mandated goals depends on the ability of diverse national contingents to overcome coordination problems and function as a cohesive force. Integrating research of PKOs and international military coalitions, we argue that as national contingents share operational experience within a UN mission, they develop common institutional practices, and become more effective at protecting the civilian population. Using monthly data on UN PKOs from 1990 to 2019, we find that increasing operational experience within a peacekeeping coalition reduces civilian fatalities significantly.