This is not the White Throne Judgment. The White Throne Judgment takes place at the end of the millennial reign of Jesus Christ in Rev 20. At the White Throne Judgment, individuals, not nations, are judged. They are judged not only according to their works but also according to whether their names are written in the book of life. Here there is no book of life.
Neither is this judgment the Judgment Seat of Christ. The Judgment Seat of Christ takes place in heaven during the tribulation that is going on in the earth. Christians, not nations, are judged at the Judgment Seat if Christ. Here there are no Christians.
This judgment is the Judgment of the Nations that takes place right after the Second Coming of Jesus. It is a judgment to sort out the nations that will populate the earth during the millennial reign of Jesus. You see, there was an inheritance promised to certain nations from the foundation of the world (Matt 25:34). Now they will find out which nations get what.
The objective of this judgment is to determine the twelve nations that will inherit a kingdom in the millennium. According to Deut 32:7-9, God divided to the nations their inheritance according to the number of the children of Israel. That would be twelve. The kings of these nations will go into New Jerusalem in Rev 21:24-26 through the twelve gates which are there (Rev 21:12, 21). When they eat from the tree of life, they will eat from twelve manner of fruit (evidently, each nation will have its own fruit from which to partake) [Rev 22:2, 12]. And this fruit will produce each month (there are only twelve months).
The basis for this judgment will be what each nation did with the believing Jews, apparently, during the tribulation. Jesus said, “Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me,” (Matt 25:40). His brethren can be located in Matt 12:46-49.
The reason treatment of the Jews is the basis for this judgment can be found in God’s promise to Abraham in Gen 12:3, “I will bless them that bless thee, and curse him that curseth thee.” The sheep nations who are on the right hand of the Lord are the ones who will have blessed the Jews by feeding them, taking them in, clothing them and visiting them (verses 35-36). The goat nations on the left hand of the Lord are the ones who will have neglected to do these things (verses 42-43).
Sheep and goats are good analogies for these nations because of references like Jn 10:1-9, 27-29 for sheep, and references like Dan 8:5, 8, 21 and Zech 10:3 for goats. In history, examples of nations who have blessed the Jews are Persia under Cyrus in 2 Chr 36:22-23 and Ahasuerus in the Book of Esther. Examples of nations who have cursed the Jews are Egypt under Pharaoh in the Book of Exodus and Babylon under Nebuchadnezzar in 2 Ki 24-25.
The sheep nations get to inherit a kingdom forever (verse 46). However, they will be subject to the Jews in this inheritance and that’s another reason why they are numbered after their tribes (Is 60:10-12; 49:22-23). The goat nations get everlasting punishment in everlasting fire (verses 46 and 41) as in Is 14:9-12.