The dust-up had the effect of both embarrassing Idriss, who spent much of the week denying that he had fled the country, and confirming the most important new fact on the ground: The strongest player in the opposition now is the Islamic Front, a loose alliance of seven factions that wants Syrians to live under Sunni Muslim law.

“They’re Salafists but not extremists,” explains Andrew J. Tabler, a Syria expert at the Washington Institute for Near East Policy. What that means is that although members of the front want a government dominated by devout Sunnis, and they probably aren’t reliable pluralist democrats, they’re at least not Al Qaeda-style terrorists.

That’s why U.S. diplomats have been trying to persuade the Islamic Front to join — or at least endorse — the peace conference that’s scheduled to begin in the Swiss city of Montreux next month.

The top U.S. negotiator on Syria, Ambassador Robert Ford, met in Turkey recently with representatives of the most important faction in the Islamic Front, sources told me. But the outcome of the talks isn’t clear, and in previous statements, the Islamic Front’s leaders have said they will not participate in any talks that include the Assad regime.