The way I see it, looking at it from Nebuchadnezzar's dream statue perspective, Babylon, Medo/Persia, Greece and then the legs of Iron, Rome which ends up with feet of iron mixed with clay. Roman rule was not replaced but became a democracy bit by bit, The Nameless War by Archibald Ramsay gives the details. A pdf file of the book can be downloaded here: https://archive.org/download/maule-arch ... 201952.pdf
The four beasts of Dan 7 start with Medo/Persia (cf. Dan 7:17), so the 4th beast is the nascent democratic beast that started to come into its own at the time of the French revolution. At the tail end of this democratic beast's rule, described in Rev 13:1,2, it becomes multipolar, with each of the ten horns having an equal say (Rev 17:12,13). So why does it say at Rev 17:10 he must remain a little while
We are told that these beasts are the mountains where the woman sits
, and that the woman is a great city having a kingdom over the kings of the earth
, (Rev 17:9,18). My guess is that the U.N. made up of the ten horns which destroy the harlot, (Rev 17:15,16,17), and therefore are doing God's work, will be the ones that will remain for a little while. It will be the interim government before the son of man and his holy ones take over, (Dan 7:11, 12,13, 14, 26, 27).
It says: But as for the rest of the beasts,
[those not part of the little horn], their rulership is taken away and there is a lengthening of life given to them for a time and a season
. The stone strikes the feet and toes of Nebuchadnezzar's dream statue and the entire statue is pulverized. Without some form of government, those who survive the great tribulation would descend into chaos. So the ones who had done God's will and destroyed the harlot, (Rev 17:16,17) will make up the interim government that will remain for a little while
That's my two cents worth but we'll have to wait and see how things unfold.