But until the last 18 months or so, the level of political correctness on this issue has been so stifling that few politicians or journalists dared to speak openly about a subject that generates immense popular fear.
Americans have not faced the same inhibitions, and there is now a burgeoning and markedly alarmist literature on the Islamic threat to Europe.
Governments need to clamp down on extremists and jihadists in ways that do not risk further alienating minority communities; their aim must be to integrate moderate Muslims better while avoiding a right-wing populist backlash.
Unfortunately, anyone looking for more specific prescriptions from America—where, after all, assimilation has a long history—will find more sound and fury than useful insights.
