The walls are going up all over Europe; we shall not see them lowered in our lifetime. The dream of “ever-closer union,” and the eventual merging of nations into a United States of Europe, is over. From the white cliffs of Dover in the west, where David Cameron refused to follow Brussels’s orders to grant welfare payments to working migrants, to the east, where Hungary’s border with Romania is marked with razor wire; from Athens in the Mediterranean south, where a populist government mocks Germany, the architect of the union’s fiscal policy, to Stockholm in the Baltic north, where the government has closed its borders to immigrants: The European Union has not only stalled on the road to union—it is coming apart.