banestrider
Chieftain
I think an interesting option of the UN would be the ability to re-spawn dead civs through a resolution. e.g. Korea was wiped out by the Mongols, when the UN is built there is an option that can grant the cities there interdependence and Korea re-spawns. This could also be a way to dissolve big empires peacefully. e.g. England controls South Africa then the UN leader, if he/she is not the leader of England then there could be an option to grant the cities in South Africa there independence. Then South Africa becomes independent cities. However, this might make the UN overpowered if the player controls the UN which is normally the case.