No way American air is going to strike Turkish troops, as part of a deliberate operation. Any American aid would have to be covert/through third parties.
I never inferred US air strike.
There are other weapons that are levelers for their air force.
I assure you the battle over Efrin is not finished. There are still a lot of ISIS that need killing in Efrin. Same with Nusra. It is running 10-15 per week now.
Turkey? Short of Erdo going away, or a financial collapse? I guess we are stuck with playing that they are not what they are.