Losing Turkey pretty much ended any hope Obama and his handlers may have had of bringing down Assad.
Erdogan pretty much agreed that Assad stays. Give it a year, you will see them shaking hands.
But really upset Erdogan can become much bigger nuisance than he is now. Closing US bases, leaving NATO, flooding EU with more rapeugees -- these are obvious threats.
One less obvious: Turkey re-oriented fully to the East has no reasons to pay back $400 billions they owe now.