This article explores possible theories of international economic policy coordination, and then proceeds to test these theories through a qualitative analysis of four EU member states – Germany, France, Belgium, and the Netherlands – and their preferences and experiences during the financial market crisis period of Fall/Winter 2008–2009. Both institutional and basic realist theories for coordination preferences are evaluated for explanatory power against the case of the 2008 financial crisis and are found lacking. Instead, this analysis finds that a comparative foreign policy theory of political constraints – institutional design, political polarization, and leader time horizons – emerges as the best fit for explaining the divergence in foreign policies among these EU member states.