Syria has me stumped. You've got the Assad supported by Russia and Iran (I believe mostly through working through Hezbollah) on the one side, the moderate Syrian rebels on the other side supported by the United States and Saudi Arabia and Jordan, ISIS on the other other side not really supported by anyone, and the Kurds on the other other other side also supported by the United States.
We want to defeat ISIS, but we don't want to get ground troops involved because that has clusterfuck written all over it in 128pt Helvetica. However the moderate Syrian rebels don't seem interested in fighting ISIS, they want to fight Assad. Assad doesn't seem interested either, he wants to fight the moderate Syrian rebels. Russia doesn't seem interested either, they want to support Assad. Same seems to be true with Iran. The Iraq army outnumbers ISIS massively, but they don't seem especially interested in fighting ISIS either. Meanwhile the Kurds have been fighting ISIS, but our ally, Turkey, wants to fight the Kurds and the Kurds aren't large enough to really deal with ISIS by themselves anyhow. Meanwhile we're bombing ISIS, but that isn't going to be very effective unless we decide to tolerate massive civilian causalities which would probably create a lot more anti-crusader resentment in the region, leading to more terrorism.
Of course that may be the easy part because stability needs to be achieved and the U.S. goal is to establish a pro-western secular democracy by supporting the moderate Syrian rebels who are not cohesive enough to be called something other than the moderate Syrian rebels.
What the hell do you do with that?
I'm starting to think the best answer is to just tell Russia, hey, you want to own this shitshow, you go ahead and own it. We'll just put a fraction of the money we'd spend on military action for humanitarian aid and resettlement of refugees and you guys can be left holding the bag of regrettable middle-east policy.