Don't you think it's a bit simpler to conclude that in this civil war, as with the Iraqi one, Western powers are fairly marginal.
Syria is kinda resolving into a proxy war between Iranian/Shi'a groups, including fundamentalists and terrorists, and Saudi/Sunni groups, including fundamentalists and terrorists.
It seems the Russians are giving some support to one side. And the West is giving some support to the other.
But the West is unlikely to get liberalism in Syria even if its side wins. The choice seems to be between dictatorship and Islamic traditionalism in various guises.
I wish that it were otherwise. But as yet, liberal democratic values don't seem to command a majority in the Islamic crescent.