If the United Nations gets it's way later this year, won't that set Bible prophecy back to square one ?

The "time of the Gentiles" in that context actually refers to the 70th week of Daniel when Israel has again been exiled and has taken refuge somewhere in the desert of Jordan. During that time the antichrist will have taken over Jerusalem and established it as a trade center. It'll become sort of a New Babylon. It will remain in Gentile hands until the last bowl judgment. Then God will begin the 75-day process of restoring the country of Israel--along with all of Jerusalem--to the people of Israel.