U.S. officials said they have long been planning for "the day after Assad" - such as training Jordanian troops to provide security. But for now, they just hope Syria will keep its chemical weapons under wraps.

In the end, Assad is still seen as having the vast support of his Alawite sect, that of the Iranian government, and with it, a ruthless ability to stay and fight to the end. Whether his inner core of support will ultimately see that as the best option, remains to be seen.

"The question is will his sect decide that President Assad has to leave as part of any transition in the country," Tabler said. "I think there is a real chance he will huddle along with his sect. The question is whether his sect will want to huddle with him or not."