The strategic logic of European integration

Why have the states of Western Europe integrated their economies since World War II? I argue that integration is best understood as a consequence of the particular international distribution of power that existed after 1945. Specifically, the West European states integrated their economies because they were minor power members of a "sponsored coalition" led by the United States and threatened by a potential hegemon, namely the Soviet Union.; Despite being confronted by a common threat, minor powers in situations like these are unlikely to integrate in the military realm. This is because their sponsor, otherwise known as an offshore balancer, will have powerful incentives to step in and defend them from the potential hegemon and from one another.; Over the longer term, however, the minor powers understand that they cannot count on the offshore balancer's support and that they must provide for their own security. Given that economic might is the basis of a state's future military power, this requires them to integrate their economies. The logic is straightforward. By agreeing to merge their assets and control them jointly, the minor powers can form a powerful economic bloc capable of balancing against the potential hegemon while simultaneously perpetuating the rather even distribution of power that currently exists among them. Consequently, they need not fear domination at the hands of the potential hegemon or one another over the long haul.; This argument is part of a general theory about how groups of states organize themselves when confronting a potential hegemon. My basic claim is that it is a threatened coalition's architecture that determines the kind of military-economic arrangements that its members adopt, and only the minor power members of sponsored coalitions will integrate economically.; I test my theory using case studies of the creation of the European Coal and Steel Community and European Economic Community, and the failure of various military integration initiatives in the 1950s. I then determine how well my theory travels to other regions and time periods by briefly considering three more cases: Europe before World War I, East Asia since 1945, and North America after 1789.