A dilemma for the West: no obvious successor to Assad

The political opposition, largely operating from exile with little credibility on the ground, has been hobbled by infighting. Inside Syria, rebels are also divided. Fighters linked to the al Qaeda terror network have become increasingly dominant, even as the US and its allies try to strengthen rebels seen as moderates with better training and military equipment.
Rebels and Islamic radicals fighting alongside them have already come to blows in some cases, and their divisions could turn into outright battles without the common enemy of Assad.