This paper examines the European Monetary Union (EMU) and the euro crisis through the lens of a robust political economy. Based on the history of monetary unions, monetary union is unlikely to survive without a fiscal union or strong constitutional constraints. The EMU has neither, and its institutional structure makes it unsustainable. Since the euro was (and is) fundamentally a political – rather than economic – project, we argue that policymakers will not allow the EMU to fail. Rather, continued movement towards greater EU-level fiscal, and ultimately a fiscal union, are likely.