In Cairo, representatives of the Syrian National Council, an opposition group, welcomed the proposal, but said there would be no negotiations until Mr. Assad stepped down.

With little immediate chance of success, the proposal reflected divisions within the Arab League over how to confront the Syrian crisis, as well as the league’s mounting sense of helplessness as the death toll mounts. Hundreds of people have been killed by security forces since the league sent observers to the country in early December, and armed opponents of the government have demonstrated growing power in recent weeks.

Twenty miles from Damascus, former soldiers and armed residents have wrested control of the city of Zabadani from the army, though few people in the town think the government intends to keep its troops away for long. Activists in the town of Douma, about 10 miles from Damascus, said Sunday that after a day of heavy clashes there, defecting soldiers controlled three neighborhoods, though the security forces were still present.

Ahmed, an antigovernment activist who spoke on condition that his last name be withheld, said that hundreds of soldiers in the area had defected in recent weeks. “If Douma is liberated, that means that the next attack will be in the heart of Damascus,” he said. “The Assad army becomes weaker and weaker, while the armed resistance and the Free Syrian Army becomes stronger,” he added, referring to a militia made up of defectors.

Feelings were just as strong at the country’s largest military hospital, in Damascus, where doctors and administrators said about 25 wounded soldiers were now arriving each week, and roughly the same number of corpses. Two soldiers from the same company nursed wounds at the hospital that they said they received in separate ambushes near the Lebanese border. They said their well-armed opponents were part of an “outside conspiracy.” “It will end soon,” said one.