I'm trying to empathise with them... I get why people become radicals of other kinds... but saying no music, no sex, live by the book, behead those who disagree... what part of that makes people think "I want to get into this, this sounds fun"?
The Arab world has valid grievances, which motivated 9-11 for example, but there's more to it than that.
You know how western teenagers have obscure esoteric fascist ideologies that was invented by some guy in the 1950s or a blogger in 2008? Islamic terrorism is basically that put into practice. Some of the sects deviate so far that they become “enlightened” and think everyone must die for a better world. Pol Pot but in a desert