This dissertation theoretically examines the variance of cooperation mechanisms in the decision-making process of the EU. I introduce a costs framework of typological conditions of interdependency – the balance between costs of preserving sovereignty rights and enhancing the decisiveness of the regional group – in order to examine the incentives of the member states of the EU to choose different strategic mechanisms with a view to maximize the utility from their interdependence. I develop deductive models that account for four strategies of cooperation (bargaining, coalition formation, regulatory management and judicial conflict-resolution) and derive analytical implications about their differential effect on the coordination of national policies at the regional level. My findings specify which strategy is likely to be used by the European states for the resolution of problems of distribution, redistribution, regulation and enforcement, and why the direction of policy coordination derived from the strategic behavior will be either centralized or decentralized.