Forces loyal to President Bashar Assad have taken five rebel-held towns south of Damascus in the past 10 days and have also put the rebels on the defensive north of the capital.
Slaman Shaikh, director of the Brookings Doha Center, told The Washington Post it appeared Assad's military was intent on solidifying control of Damascus and the center of Syria. "They will be more willing to fight it out," he predicted.
A possible outcome could be the rebels boycotting the peace talks in Geneva due to their strategic disadvantage. "It will complicate efforts by international players to engage with some of these groups and persuade them not to veto Geneva," Shaikh said.
Rebel groups indeed sounded less inclined to sit down with government representatives. "Whenever there is any international diplomatic effort, the regime tries to make more military advances," said Musab Abu Qatada, spokesman for the rebel military council in Damascus.
The rebels have expressed dismay that the international effort to curb Assad's chemical warfare capabilities had distracted the world's attention from the continuing conventional-warfare carnage Assad has inflicted on the civilian population.