The conclusion attempts to draw together the diverse strands in the book and to highlight common themes across the three areas covered in the chapters: East Asia, Latin America, and Europe. The leading theme of the book has to do with the place of power in regional integration: power within regions, power between regional and external actors, and traditional interstate relations that impinge on relations within and between regions. Specifically, we take up the role of hegemonic external actors such as the US and China, the role of core states within regions (Germany, China, Japan, Brazil), and the role of noncore states including small and middle powers. Drawing on work in the “new regionalism” literature as well as Katzenstein’s pioneering work on the American imperium, the chapters elaborate on these power-related themes. Interstate rivalries persist even if within an environment of complex interdependence and regional rivalries.