It has now devolved into a vicious circle with mutually reinforcing dogmas of Jihad/Crusade. The undertones were obvious in the Brexit episode; French large cities are just as much tinderboxes as any US metro area; Belgium has laws barring discrimination based on race/origins/... in housing and employment, but has made it near impossible to make an individual complaint stick and any cases that explode into the spotlight get buried with a slap on the wrist; etc, etc, ...