For a Dutchman driving his caravan to the Costa del Sol, the only thing to remind him that he had crossed borders used to be the successive text messages welcoming him to Belgium, France and Spain. That was before this summer's migrant crisis-and last weekend's terrorist attacks in Paris. Now the liberty to roam the 26 countries in the border-free Schengen zone, which Jean-Claude Juncker, the president of the European Commission, calls a "unique symbol of European integration", is under greater threat than at any point since its inception.
展开▼
