A society that was not foolish to the point of suicidal insanity would have prevented this problem years ago. A 180 degree conversion of mind, heart and soul is the only thing that can respond to this adequately. I expect nothing but the same useless ritual, moral grandstanding and fraudulent hand-wringing that Charlie Hebdo produced.
A healthy society would respond to this set of jihad attacks with riots and the burning down of mosques and Muslim neighborhoods and calls for their expulsion. Not, as in the US after 9/11, with a self-hobbled war, massive lies about the nature of the enemy and an increase in Islamic immigration.
Only a bloodbath can save Europe, and the Europeans lack the guts for it.