There are no nations being judged at the Great White Throne. So that is incorrect. Only individuals who have been brought out of Hades for their final judgment.
The KJV uses the word "nations", but perhaps I took for granted that we all knew this is not a reference to the various nationalities and countries. Nations is actually the Greek word ethnos and it's a reference to race/ethnicity; it's referring to non-Jewish people, but Matthew 25:31-46 is not a standalone passage sufficient to define who a true Jew is; the goats are unbelievers (spiritually non-Jewish people) who have rejected Christ, the world Savior. As we all know, a true Jew is one who has a circumcised heart and spirit per Romans 2:29.
Here's your actual Biblical definition of what the "nations" are:
G1484 - ethnos - a race (as of the same habit), that is, a tribe; specifically a foreign (non-Jewish) one (usually by implication pagan): - Gentile, heathen, nation, people.
Tell me, who do you think these people are in Revelation 20?
Rev. 20:11-12
11And I saw a great white throne, and him that sat on it, from whose face the earth and the heaven fled away; and there was found no place for them.
12And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is
the book of life: and the dead were judged out of those things which were written in the books, according to their works.
If you guessed they are unbelievers with hearts and spirits that are not circumcised (spiritually non-Jewish) then you guessed correctly. They are the "nations."