Never before has it been so important for policymakers to balance regional and global forms of peacekeeping. Although the United Nations Security Council retains primary responsibility for maintaining international peace and security and is the single largest source of peacekeepers, some regional organizations, particularly in Africa and Europe, are playing increasingly important roles. This article analyzes the relationship between UN peace operations and those conducted by regional organizations. After summarizing recent trends in regional-global collaboration it analyzes the opportunities and risks of increasing the regionalization of peace operations. Current policy challenges are daunting, not least because better-resourced missions alone will not bring peace to contemporary warzones. Rather, policymakers should clarify the nature and limits of UN peace operations; ensure partnerships between the UN and regional organizations can deliver effective peace operations in the field; and embed peace operations within a viable conflict resolution strategy to end the war or crisis in question.