I found this article useful in developing my understanding of the situation. It's by Nafeez Ahmed and it's called "No Piers Morgan. This is how to destroy the Islamic State"
http://goo.gl/q9s3eG
I'll also include one of the quotes I liked:
"So thin is IS’ veneer of religious motivation that French journalist Didier François, who was held hostage by IS for 10 months before his eventual release, revealed that his captors were so uninterested in religion they didn’t even have copies of the Qur’an, and never engaged in religious discussions."
Caption this Meme
