ABSTRACT
The UN Security Council has never possessed a monopoly on either the authorization or conduct of peace operations. But it has become the predominant source of authority for legitimizing such operations, and the UN's "blue helmets" have conducted more than any other entity—seventy-one missions as of May 2017. This chapter provides an historical overview and analysis of the development of peace operations as well as three key contemporary debates concerning the relationship between the UN and regional arrangements; participation in peace operations and who provides UN peacekeepers; and the use of military force. The world organization made major strides in terms of professionalizing its operations. "Professionalization" refers to the development of a cadre of competent bureaucrats, relevant doctrine, guidelines and procedures for peacekeeping, and the capacity to engage in systematic reflection on the UN's failures and successes. A more proactive approach to the use of force raises the risk of higher casualties among UN peacekeepers.
