Under Chapter VII of the United Nations Charter, the UN Security Council may authorize the deployment of armed forces for peacekeeping or peace-enforcement purposes. Depending on the situation, the Council may request that member states provide their own troops under UN operational control or it may enlist regional organizations and coalitions of willing countries to perform these tasks. Peacekeeping troops are members of their respective armed forces and are not an independent “UN army.” A 2008 capstone doctrine, which is not an official document, attempts to codify the principles of UN peacekeeping, which include consent, impartiality and the minimum use of force.

Proponents argue that if the conditions for peace are present, the deployment of a lightly armed UN force can help wind down conflict and protect civilians from the ravages of war until the underlying causes of the conflict have been addressed. Peacekeepers, who are often referred to as Blue Berets or Blue Helmets (because of their light blue headgear), can help in a variety of ways, including by helping to separate former combatants, providing confidence-building measures, monitoring power-sharing arrangements and electoral assistance, and assisting with economic and social development.

Despite the many challenges of preventing and responding to violent conflicts, peacekeeping has had some success. It is one of the few global institutions capable of deploying on short notice to help prevent the outbreak of large-scale violence or to wind down an ongoing conflict. It is also a cost-effective tool, at one-eighth the expense of traditional U.S. military engagement, without the presence of U.S. troops on the ground.