He had spent the day with the leaders of Syria’s myriad armed factions, trying to persuade them to disband. Over seven weeks after the fall of Damascus, the fate of these groups is still uncertain.

The rebel chief who led the overthrow of the longtime dictator Bashar al-Assad has been declared the head of government for a transitional period.

The new leadership of the country said the rebel coalition leader, Ahmed al-Shara, would serve as president during a ...