Over the past two decades, monetary crises have played a key role in spurring increased monetary cooperation. From one, materialist, vantage, such crises appear as exogenous shocks, which matter primarily as they alter the material incentives to cooperation. However, such frameworks obscure the importance of debates over the meaning of crises, monetary understandings, and state interests themselves. I therefore offer a constructivist theory of crises, and trace the post-1980s evolution from New Classical interpretations of crises, which stressed domestic policy errors and obscured interests in cooperation, to subsequent New Keynesian interpretations, which have stressed market instabilities and legitimated greater cooperation.