This is the real goal of US policy in Syria: get rid of Bashshar but keep the regime

"Looking ahead, the United States and its allies need to encourage more stable transitions of power — where possible, maintaining national institutions, such as state services and the army, but transferring control of them to a new, more democratic leadership. That’s what happened in the mostly bloodless revolutions of Egypt and Yemen, where the United States pushed the army generals to abandon the dictators." (thanks Electronic Ali)