This is a religious civil war.
Who’s side are we on?
Are we going to fight for Sunni Islam or Shia Islam to take the upper hand in a particular geographic reason?
Why? They will still be fighting each other as they have been for 1400 years and the religious war will flare up again either in Syria or somewhere else.
I fail to see why we need to support one faction of Islam or another faction of Islam.
I don't think you are the only one does.
The war in Syria does have elements of the Shia-Sunni struggle present, but the real war is Islam against everyone else on Earth.
From the JQ Adams quote above
and he (Mad Mo) declared undistinguishing and exterminating war, as a part of his religion, against all the rest of mankind.