Hard to see how this one plays out. I think the Hezbollah-card is eroding the more Arab blood Assad sheds. Would he try to provoke an Israeli response to save his neck. An IRBM strike or Golan land grab to rally the flag.
What to do if we want to get rid of the Assad regime, but not want it to be replaced by a Saudi proxy based on wahhabism?
It is too late for a Bashar-Lite regime in Syria.