The most extreme faction in Syria didn't just spring up naturally—it was purposely built through a series of daring Iraqi prison breaks, the New York Times reports. With demand for fighters high, and the US recently departed, the group now known as the Islamic State of Iraq and Syria filled its ranks with a series of prison breaks, beginning in July 2012 and culminating in a massive raid on Abu Ghraib a year later. They called the strategy "Operation Breaking the Walls." One inmate freed in the Abu Ghraib raid explained that like many he'd been radicalized in prison, and was freed by a corrupt guard.
Once freed, ISIS gave him a choice: Stay and fight in Iraq, or go to Syria. Many leaders chose the latter. "They felt they would be freer" there, he says. The prison break story has fueled the rebel conspiracy theory that ISIS is a pawn of Bashar al-Assad's regime, and that Iraq's Assad-friendly government helped free its fighters. There's no evidence supporting this, and many freed ISIS fighters are fighting Iraq's government, too. But McClatchy has an in-depth piece on moderate rebels' animosity toward ISIS that notes some circumstantial evidence: Assad's forces have largely left ISIS alone, it notes, and ISIS has mostly abducted and tortured Assad opponents. "It was like Syrian intelligence," says one rebel chief who fell into the group's hands.