Bashar Al-Assad: Either Help the Sunnis Win in Syria, Or Risk a Global Sunni-Shiite Battle

 'It is apparent that Hezbollah’s presence and zeal for supporting Assad has been contingent on the fact that President Obama has been repeatedly sending the signal that he was not willing to back up America’s red lines and was not committed to do what was necessary to produce victory for the opposition and save Syrian lives.'

Generally even more true of Russia, they are happy to be there while they get paid for their arms and lose zero troops, but they are never going to risk WW3 over somewhere not even in their near abroad.