The answer KT to your New Jerusalem being Washington Dc.
On that day his feet will stand on the Mount of Olives, east of Jerusalem, and the Mount of Olives will be split in two from east to west, forming a great valley, with half of the mountain moving north and ohalf moving south . Zechariah 14:4


On that day life-giving waters will flow out from Jerusalem, half toward the Dead Sea and half toward the Mediterranean, flowing continuously in both summer and winter. Zechariah 14:8 Not in Washington but where the dead sea and mediterranean are.
The LORD will be king over the whole earth. On that day there will be one LORD, and his name the only name. Zechariah 14:9
Then the survivors from all the nations that have attacked Jerusalem will go up year after year to worship the King, the LORD Almighty, and to celebrate the Feast of Tabernacles Zechariah 14:16

God is coming to establish his kingdom not in Washington but exactly where it says in Zechariah 14:18

Revelations 21.1 describes a new heaven and a new earth because the old one had been done away with and remade over. God will rule just like he said in Zechariah 14:4 on his holy mountain Zion, Not Washington, the vatican, eu or any other place.