The EU is an institution praised for uniting Europe by pulling its people together. There is a lot of talk currently going on regarding the independentist movement in Catalonia. Ironically those two phenomenons are causally linked together. Fernando Betancor, an American economist living in Madrid puts it better than me:
The current crisis afflicting Spain and its wealthiest region, Catalonia, is indicative of both of Europe’s initial success and ultimate failure. The EU – and NATO – were successful in creating a large, borderless, free market and a security zone that seemed to make another European war inconceivable. That reduced the advantage of belonging to a large state, one with a large internal market and a sufficiently large military to ensure domestic security. Inside the European Union, a nation like Luxembourg could compete on equal terms with Germany in the common market of 500m and had no more to worry about invasion than France or Italy. With a population 13 times as large as Luxembourg and an economy four times greater than the diminutive Grand Duchy, the Catalans felt that they could make a going concern of their country.