Well, Obama could not very well set up a no fly zone before the Russians swooped in to help Assad because Obama worked for years (remember Hillary Clinton’s Benghazi arms-to-ISIS treason?) to get rid of Assad by funding ISIS AND the rebels.
It’s all about allowing or preventing a Qatar-to-Europe gas pipeline through Jordan, Syria, and Turkey. That would compete against Russian gas, and cause a price collapse. Russia won’t allow it because US economic sanctions (including lowering of oil prices) to punish Russia for taking the Crimean peninsua have hurt Russia.
Naturally, the US wants to help Qatar (where the US maintains a critically important air base for flying drones to Yemen, Iran, etc), so together the US and the Arabs have funded the so-called rebels (who did a poor job against Assad) and then funded ISIS (who did a pretty good job and sold $800 billion in oil to Turkey).
That put the US into direct opposition against Russian interests, so naturally Russia stepped in and creamed the oil truck fleet, destroyed as many rebel groups as they could, and took out some ISIS bad guys in the process. That’s what the US could have done, had it allied with Assad. But of course, that would have alienated Qatar, and bye-bye air base in Qatar as a result.
Maybe the Joint Chiefs have hunkered down with our supreme commander to plan sending in F35 Lightning II’s and F15 Strike Eagles and F/A18 Super Hornets and F22 Raptors to obliterate that Russian S-400 radar and missile system and the aircraft defending it.
And maybe the USA will back off the way it should have long ago. At least our supreme commander can tell Qatar “Hey, if you want to go in and take out that missile system, have at it. Let us know when you’ve eliminated it and we can pick up where we left off. Otherwise, I’ve got to make Tee time.”