Many mujahideen — and especially those who joined ISIS — proved not to be so brave after all, Syrians say. Instead of fighting the regime, they helped the group prey on other rebel groups, snatching territory already won by the opposition to carve out ISIS’ so-called caliphate.

They made little effort to understand the culture, often appearing lost in Syria. And most locals recoiled at their simplistic and extreme interpretation of Islam.

The foreign fighters in ISIS eventually became symbols of its worst abuses — the kidnapping, torturing, and killing of Syrians; a blind and dangerous brand of jihad. They fought other rebels to create their own vision of a religious state in Syria, accusing their less extreme rivals of not being true believers.

“They kill people under the name of Islam, but Islam’s not like that,” said Barakat, who knew many of the mujahideen in Syria. “And they don’t really fight the regime. Most of their battles were with other rebels. So they are killing Muslims — and their main victims are rebel fighters or innocent people.”