The problem now appears to be how people react, in France and elsewhere. France has around 6 million muslims, the highest of any Western European nation, and feelings have been running high for some time.
People will see that the gunmen escaped to the Banlieue, the suburbs around Paris, which are effectively a police no go area. Political tension is palpable and more than a thousand cars are torched every year.
With Marine Le Pen riding high in the polls it will be Hollande's unhappy job to calm the feelings of non-muslims. There is a clear threat of backlash.
Elsewhere, there have been anti-muslim riots in Germany, and nationalist parties are on the rise in several European countries.
These are going to be difficult times.