Everything I've said here reflects long-standing U.S. policy under multiple administrations and in multiple foreign policy situations -- dating all the way back to World War II. And it's based on all the objective reasons why that policy is in place.
In fact, the legal and diplomatic situation with Jerusalem is very similar to what the U.S. faced with the partition of Berlin before the reunification of East and West Germany.
Thus answering your own question vis a vis "the left's narrative."