Oh BS !
They will not look into who and how because the collective socialist delusion that islam is peaceful will be shattered when they find out the truth.
France is a powerful country, and the French are highly capable. All they need is a green light to eliminate the problem and it shall be done vigorously.
The french will put up with this cr@p for only so long. Once they decide to take action, the French can and will be quite barbarous and they won't care what the rest of the world thinks.