Salafi-Jihadism "The History of an Idea" by Shiraz Maher
Shiraz Maher
I almost picked this up yesterday, but was waiting to get a chance to read a review of it. I'll have to go grab it.
Ranger Games:
If you want something that similarly tackles pyschology and awful decisions, check out Blackhearts by Jim Frederick. It details awful leadership and environment that helped create a situation where five soldiers gang-raped and killed an Iraqi girl, and murdered three members of her family. It's a heavy read, but important for learning how to possibly prevent such things from occurring again. Mahmudiyah rape and killings - Wikipedia