According to the back story, these Muslim “refugees,” many of whom were from Africa, demanded free food in a restaurant. When they were told “no,” they started to riot and loot.
National borders and immigration restrictions exists for the same reasons that prisons and mental institutions exist: because certain people are not capable, either by natural defect or intentional choice (the latter moreso than the former), of living peaceably in society.
Taking a man out of the Muslim third world and dropping him into Europe does not make him a “European” any more than it makes a mouse that occupies a stable into a horse. As the saying goes, “you can take the rat out of the hood, but you can’t take the hood out of the rat.”
In this case, you can take the Muslim out of the Muslim world, but you can’t take the Muslim world out of the Muslim.