ABSTRACT With the mushrooming of overlapping regionalism in Africa, there has also evolved a dense web of relationships between Africa and the European Union (EU) on matters of interregional security relations. In this context, the EU increasingly favours regional groups such as the G5 Sahel instead of its established partnerships with regional economic communities or the African Union. To account for these rather puzzling preferences, this study argues that the EU’s emphasis on the security-development-migration nexus overrides rational forum shopping logic, leading to cooperation with the G5 Sahel in response to the crisis in that region rather than with traditional partners embedded in the African Peace and Security Architecture. Drawing on a wide range of data including interviews, this study considers the dynamics of interregional forum shopping and the security-development-migration nexus. It thus relates these to current trends in the Africa–EU partnership on peace and security, considering both sides of the relationship.