The European Union has no border patrol. It’s one of the many ways in which the bloc lacks power, with its member countries jealously guarding their sovereign prerogative to enact their own laws about defense, police and coast guard. This vacuum of authority, and the failure of EU policy-makers to anticipate how events in faraway Libya or Syria might trigger the flood of refugees now swamping Europe, are some of the reasons the group of 28 European nations originally founded as a common market has failed to deal more firmly and effectively with what has mushroomed into a major humanitarian...