Delegating Responsibility explores the politics of migration in the European Union and explains how the EU responded to the 2015–17 refugee crisis. Based on 86 interviews and fieldwork in Greece and Italy, Nicholas R. Micinski proposes a new theory of international cooperation on international migration. States approach migration policies in many ways—such as coordination, collaboration, subcontracting, and unilateralism—but which policy they choose is based on capacity and on credible partners on the ground. Micinski traces the fifty-year evolution of EU migration management, like border security and asylum policies, and shows how EU officials used “crises” as political leverage to further Europeanize migration governance. In two in-depth case studies, he explains how Italy and Greece responded to the most recent refugee crisis. He concludes with a discussion of policy recommendations regarding contemporary as well as long-term aspirations for migration management in the EU.