It is far more likely that Russia breaks its alliance with Assad than the US chooses to walk away from Turkey.
When Russia wanted the US out of Syria, they gave Turkey a deal on S400 air defenses. Russia can’t offer enough to make Turkey willingly accept another million refugees. So, Putin’s best move on Thursday would be to offer Turkey control over all of Syria, except for the Russian naval and air bases, in exchange for leaving NATO and becoming best friends. Even if Erdogan is an SOB, that would not be good for the USA.
What?
You think Turkey will walk away from $3.5 billion worth of contracts with US military manufacturers? Not likely.