Isn't it obvious??
Frances support of Israel.
Her participation in the illegal Iraq invasion.
The economic and racist oppression of her minority population.
It's all there.
For recruitement. The more they are able to create a situation in a country where both non-Muslims come to distrust the Muslim population, and where Muslims start to feel prejudiced against, there will be fertile ground for groups like Daech.
It's a viscious cycle and one that they understand well; we do to but we still want to see visible action each time there is an attack.
France is the perfect country for it, due to the existing frictions (partly due to the National Front's rise on the back of blaming immigration for the country's economic problems) and large Muslim population, complete with many dissaffected youths, etc.
For example, since the state of emergency was called following the Bataclan attack, 3000 raids were carried out, the majority on Muslim individuals and families, resulting in only 6 cases that required further investigation.
You can see how this would both create distrust and a feeling of not belonging on the part of Muslims, and allow the idea to grow in the rest of the population that it's okay to profile and single out a whole group of people, and specifically this one.
This is generally recognized to be the current situation and is the one argued by most security and intelligence experts.
Most of the call for a war on the religion or describing it as a clash of religions or civilizations are politicians who have the most to gain from it, namely the far right ones who have made immigration their whole platform or put it at the at the center of it.
Daech is being run by very sophisticated people with much experience in international politics; the original fanatically religious elements have been deposed or killed and it is now a recruiting and propaganda machine who is actually having trouble recruiting people to join by traveling to their territories to train or fight, so are focusing all their efforts on recruiting local people to act alone and claim allegiance when the commit terror acts.