In 1980 the Israeli Knesset passed a Law designating Jerusalem as the captital of Israel. The UN Security Council passed a resolution 14-0-1 declaring the move null & void. (the US abstained)
It’s been a political football ever since. Even Republican administrations squirm when the subject comes up.
That makes it the capitol then. Why is it an argument?
(Assuming, of course, that "Knesset" has the requisite authority.)
Screw the UN, they don't run anything but their mouths.
Why do we care anyway? Is mail not getting delivered correctly or something?