THE euro-area debt crisis exposed a critical need for stronger European financial safety nets and institutions. In March 2010, Thomas Mayer and Daniel Gros, two German economists, made a strong case for the creation of a European Monetary Fund (EMF). In the end, European leaders agreed on a European Financial Stability Facility (EFSF) in May 2010. This was later transformed into the European Stability Mechanism (ESM), which today works alongside the IMF in Europe’s financial-assistance programmes. The creation of the ESM was a major step in the process of integrating and completing the euro area. It offered a powerful mechanism to backstop sovereign debt markets and deal with sudden stops in capital flows at a time of acute crisis. But over the years, as the more fundamental flaws in the architecture of European Monetary Union (EMU) have come to light, this approach has proved its limits. The ESM now needs to evolve.