I listened to an informed view on the Spectator podcast this week venturing that radical groups such as ISIS only push people over the edge. How they get close to that edge is the more interesting story.
Back when we lived on the Isle of Dogs in London I used to have to run the gauntlet of walking home along the river path where young males of Bangladeshi origin, usually aged between 8 and 15 frequently shouted abuse at me and on one occasion threw an empty bottle at me. A beer bottle.
At that stage in their development you'd hardly have imagined that they were going to turn into model Muslims, but oddly enough, I think there's a fair chance that some of them are right now getting close to the fanatical edge.