this map of ISIS (in gray) on the wiki site to see specifics.
From all of this has emerged a conversation about why some people turn to radicalism and others don't. The New York Times ran a video about three friends, two who are working normal jobs and the third who left to join ISIS. It doesn't really offer any specific reasons why the third friend left home. The video just chronicles someone whose personal beliefs were no longer in sync with his friends'.
I don't think this line of inquiry - trying to understand the why of radicalism - will be a particularly fruitful path. So what if you discover the ins and outs of one particular person's reasons for joining ISIS? A thousand people might have a thousand reasons for doing the same thing.
In the short term, better to focus on a strategy to curtail enrollment. For that, look no further than our country's own relationship with home-grown terror: the Ku Klux Klan. They too enjoyed high enrollment for a while. But what happened?
As the story goes, one man infiltrated their organization, learned all of their secret code words, handshakes, whatever, and aired them over the radio on children's programming. That was it. Over time, with children repeating all of their mumbo jumbo, the mystique of the Klan was broken. It became a bad joke to join the KKK. For more of that story, read here.
My idea is to do the same with ISIS. Make a video of some clowns talking about clown jihad. Have a kid saying that challah is great. Make some Weird Al remake of some of their youtube releases. Above all, make the entire thing ridiculous.
You get the world laughing at these clowns, and their numbers will tank.