An interesting article I read by a gentleman apparently of Arab descent (but translated from the French!) seems to claim that France is her own worst enemy in terms of why such attacks as happened most recently in Nice, several months prior in Paris, and then the Charlie Hebedo horror etc. continue to happen above all in France, not Germany, England, Sweden, Denmark, Holland or other countries with significant Muslim immigrant populations.
France makes an almost manichean distinction between Church and State, more than any other nation, this then polarizing those non-indigenous ethnic groups within the country who feel disenfranchised by the the Catholic state and overarchingly Christian-French culture, even if only nominal.
Furthermore, unlike say, Germany or the Scandinavian countries, France had large non-white colonies for centuries, was therefore used to incorporationg, though not necessarily INTEGRATING, these diverse French-speaking non-Christians into their midst.
Now, it seems, it's payback time and France is feeling the full brunt of her traditional "openness":-)
Makes sense to a degree, wouldn't you say?