I actually think the best way to beat them is just using their own beliefs against them. When you capture one, force feed the pork, impale them and then bury them inside the carcass of a pig. 
They'll quickly realize that you're not someone to fuck with.
This is more correct than you may realize. The "modern" Islamist has a 10th century mentality. Respond with overwhelming, disproportionate force and they will go back to being quiet and good. Our problem is that we wish to respond to every problem with compassion, and that makes them hate us more.
Send food to starving Muslims and they will hate you forever for their own weakness.
Nuke a Muslim city and kill half a million of the faithful and they will respect you for 3 generations.
We just need to get our heads out of our asses.