If anyone thinks that the US will ever pull out of the UN or stop funding it, they are very naive. The Democrats, Republicans, academic and economic elite in this country is firmly internationalist. Don't even waste your time fantasizing about the US leaving. It's just a matter of which faction is in charge.
I think that there should be an effort to reform the UN. Currently, the UN is an association of Executive Branches. It should be modified to add a legislative branch, with the representatives being selected by vote, There should be some statement of limited powers, and a statement of passive rights (you have the right to free speech, but not to own a radio station....)
If that was done, and done well, there would be some improvement. If not done, then The US should develop a competitor, with members limited to states with limited powers and individual rights. Members states could have their territorial integrity guaranteed by the members, in return for their contribution.
Then the UN could wither away or reform. Their choice.
One can have free international trade WITHOUT beikng a socialist globalist POS...
...I support international trade, but I don't think the UN has anything to do with it...