Such travails could boost the new chief’s credibility with the fighters.

Abu Moawiya, a former builder who is now a local battalion commander near Maaret Misreen, said he’s ready to work with anyone who is based in Syria.

As does Bitar, Abu Moawiya spends much of his time with his men, including on dangerous jobs, such as making homemade bombs by stuffing explosives into metal pipes.

Abu Moawiya insisted that he be identified only by his nom de guerre rather than his full name, fearing retribution against his family by the Assad regime.

Trying to widen support, the new military command will have to finesse its position regarding one of the most effective fighting groups, the al-Qaida-inspired Jabhat al-Nusra, branded a terrorist organization last week by the Obama administration.

The group appears to be popular among rebels, and for fighters like Abu Moawiya, a former al-Nusra member, sidelining it is treason. He said he quit al-Nusra in the summer because it didn’t want to accept his friends, but that ‘‘our hand is in their hand as we liberate Syria from Bashar.’’

Idris was trying to walk a middle line, neither embracing nor rejecting al-Nusra. He said the group chose not to be part of the unified rebel command, but that ‘‘they are not terrorists.’’

He estimated that about one-fifth of al-Nusra’s fighters are foreigners, but said he believes they will leave Syria once the regime has been toppled. The Syrians in the group, which is believed to number several hundred fighters, could be lured back to mainstream Islam after the war, he said.

The presence of Islamic extremists among the rebels is one of the reasons the West won’t equip the Syrian opposition with sophisticated weapons, such as anti-aircraft missiles.

Idris said with such weapons in hand, his fighters could bring down the regime within a month. Without foreign military help, he estimated it could take up to three months. Idris claimed that more than 120,000 armed men are fighting Assad’s military, a figure difficult to confirm independently in the chaos of the civil war.

Assad’s troops are stretched thin after a 21-month-old conflict. They've also lost ground, particularly in northwestern Syria, but have kept rebels pinned down with air bombardments.

Recent U.S. intelligence reports indicated the regime may be readying chemical weapons and could be desperate enough to use them. Syria is said to have one of the world’s largest chemical arsenals, but the regime insists it won’t use them.

Idris said Assad ‘‘can and will’’ use chemical weapons unless the international community forces him to leave.