To the utopians of capitalism, the Irish experience should be a reminder that the biggest booms can produce the biggest busts, and that debt and ruin always shadow prosperity and growth. To the utopians of secularism, the Irish experience should be a reminder that the waning of a powerful religious tradition can breed decadence as well as liberation. But it’s the utopians of European integration who should learn the hardest lessons from the Irish story. The continent-wide ripples from Ireland’s banking crisis have vindicated the Euroskeptics who argued that the E.U. was expanded too hastily, and that a single currency couldn’t accommodate such a wide diversity of nations.