The debt crisis in several member states of the euro area has raised doubts on the viability of European Economic and Monetary Union (EMU) and the future of the euro. While the launch of the euro in 1999 stirred a lot of interest in regional monetary integration and even monetary unification in various parts of the world, including East Asia, the current crisis has had the opposite effect, even raising expectations of a breakup of the euro area. Indeed, the crisis has highlighted the problems and tensions that will inevitably arise within a monetary union when imbalances build up and become unsustainable. This note discusses the causes of the current European crisis and the challenges that EMU countries face in solving it. Based on this analysis, it derives five lessons for regional financial and monetary cooperation and integration in East Asia.