Hassan Hassan writes: Abu al-Mutasim, 18, from a Syrian border town in the province of Deir Ezzor, joined the rebellion against the regime of President Bashar al-Assad in early 2012. He left his family home in Bahrain, where his parents worked, and fought for the Free Syrian Army for a few months before joining the hardline group Ahrar al-Sham. Around the end of the year, disillusioned, he went to visit his family. His parents banned him from travelling back to Syria. But last summer he returned to join the Islamic State in Iraq and Syria (Isis), now renamed the Islamic State.

I asked him what he would do if his father were a member of Jabhat al-Nusra, al-Qaida’s official franchise in Syria, and the two met in a battle. “I would kill him,” he replied firmly. “Abu Ubaida [a prophet’s companion] killed his father in battle.” What drives people such as al-Mutasim? I faced this question directly recently, as I saw Deir Ezzor, the province where I too come from, overrun by Isis, and as the group carried out some of the Syrian conflict’s grisliest atrocities. [Continue reading…]