This concluding chapter summarizes the findings of this book and revisits the six hypotheses introduced in Chapter 1, in the light of the empirical investigation. It then turns to a discussion of open questions and future research agendas. Finally, it summarizes the main practical conclusion of this book. To achieve international cooperation, neither grand visions of political leaders nor technocratic fine-tuning of the machinery of international institutions are enough. Substantial improvements in international cooperation are difficult, because they need to go hand in hand with institutional and structural changes at the domestic level. The good news is that this book hopefully helped to demystify the origins of international conflicts. Conflicts are neither the result of an anarchic international system nor the ‘natural’ consequence of conflicting national egoisms, but can be traced to concrete deficits of the domestic models of capitalism. These capitalist models are dynamic and internally contested, which gives hope for the possibility of international cooperation.