There have never not been riots in Greece and France, ( I suffered my worst physical injuries ever at the hands of Greek riot police in 1986 protesting the US using Europe as the platform for bombing Libya). It was popular protest in Europe that freed many states from their Soviet domination in the years directly following that. Protest is alive and well in Europe despite the increasingly draconian laws being enacted to limit it. Europe has had to deal with taking former Soviet Block nations that were hallmarked by backward, stagnated economies and setting them on a road to economic parity within the Eurozone. A mammoth undertaking I'm sure you would agree. Given the diversity of nation, culture and language that this has taken place peaceably and with really incredible speed is a testament of the determination of all Europeans to work together. Personally I hope the political evolution of Europe continues on the same track to the point that nations are really the equivalent of your states. A single but highly diverse superstate. As for divisions in class, race etc.... I think that Europe does have many issues but as I hinted progress has been rapid and peaceable, the one exception being the Balkan War. Europe has porous borders with Africa and Asia and has large immigrant populations that are very well intigrated and have made themselves at home here. And within Europe itself there have been large migrations too. New member states find their people moving to the likes of the UK, and peripheral states find their populations migrating to take up the slack left by the first migration. Europe is very secular. In any major city you find large communities from many countries. And if anything I would say there is less disparity and far less endemic racism in Europe than there is in the US. Though we still see politicians using race as a political rallying call for a certain type of voter they are a tiny minority.