From Scandinavia to Italy, European societies are, to a greater or lesser degree, struggling with the integration of their Muslim populations. The terrorist attack on the offices of the satirical magazine Charlie Hebdo by assailants claiming to be avenging the Prophet Muhammad has raised questions once again about whether France, the European country with the largest Muslim minority, has a particular problem.

While it isn’t possible to draw a line of causation between the actions of three gunmen and a society’s failures over...