BEIRUT, Lebanon — Fighters from the fastest-growing al-Qaida franchise in Syria have repeatedly clashed with other rebel brigades, seizing towns, replacing crosses on churches with black flags and holding classes to teach Syrian children to battle "infidels," meaning anyone who is not a Sunni Muslim.
Since the Islamic State in Iraq and Syria, or ISIS, announced its presence in Syria this year, it has emerged as the leading force for the foreign fighters streaming into the country, exploiting the chaos of the civil war as it tries to lay the groundwork for an Islamic state.
"They want to carve out a jihadi state or a jihadi territory and obviously anything above that is gravy, like overthrowing the Assad regime," said Bruce Hoffman, director of the Center for Security Studies at Georgetown University. "I don't think they have ambitions of taking over the entire country, although they'd be happy to."
While the Syrian rebels initially welcomed the group as a powerful ally in the civil war against President Bashar Assad, many now resent it for putting its international jihadist agenda ahead of toppling the government. Antigovernment activists say they detest the group's brutality and imposition of strict social codes, and even other Islamist rebels say the struggle's focus should be on leadership change.
The tensions have set off frequent fighting between rebel groups that has undermined the effort to combat the government and could complicate efforts to dispose of Syria's chemical weapons. An advance team from the Organization for the Prohibition of Chemical Weapons arrived in Damascus on Tuesday to discuss with Syrian officials the logistics of destroying the country's chemical arsenal. Officials from the group said keeping its personnel safe during a raging civil war would be extremely difficult.
An American official told the New York Times that ISIS was smaller than the first al-Qaida group to emerge in Syria, the Nusra Front, and a "tiny" part of the armed opposition, but that the group appears to be growing by attracting extreme foreign fighters.