What does the United States owe to the Kurds and what do the Kurds owe to the U.S.? Only that which can stand on its own.
No simple reciprocity or look the other way favors. No strings attached.
It is difficult to think of a worse case of reciprocity than the Soviet Union and Nazi Germany.
As to anyone invoking quid pro quo, I suggest the Jan. 11, 2017, issue of Politico. Making up dirt versus looking for that which exists.