Catalonia's independence referendum set in motion a chain of events whose consequences will be felt across Spain for years. A few weeks after the vote, which took place Oct. 1, Madrid reacted to Catalonia's subsequent declaration of independence by dissolving the Catalan government, taking direct control of its institutions and calling an early regional election for Dec. 21. But Catalan society is so divided, and the political and emotional distance between Catalan nationalists and Spanish unionists so big, that the vote alone will not end the region's problems. The gulf that separates nationalists from unionists raises questions about Spain's future. The country that managed to build a democracy after the end of a dictatorship in the late 1970s now seems disoriented as it endures its biggest crisis in four decades....