Syria's Assad has used the presence of jihadis in the rebellion against him to solidify support on his side. Assad or the jihadis is the choice Assad has given his people. Enough have chosen Assad to allow him to keep fighting despite the casualties.
Assad has also tried to put this choice to the West. Who is worse, he can ask? Me or ISIL?
This has allowed Assad to leverage our campaign against ISIL as more reason for his supporters to just hang on despite the costs so far. Assad can argue that he is our partner against jihadis--with our air strikes on ISIL as evidence.
Why don't we turn this argument to our advantage?
Can't we argue that we still want Assad to go, and that our air strikes on ISIL--rather than being a sign we side with Assad--is a sign that we won't let the jihadis replace Assad?
Wouldn't that assurance to Syrians tired of fighting with their backs to the wall that their decision to turn against Assad isn't a decision to let the jihadis win bolster our long-term goal of having a Syria free of jihadis and Assad?