Listen to Papa Ioseb

A nation is a historically constituted, stable community of people, formed on the basis of a common language, territory, economic life, and psychological make-up manifested in a common culture.

It goes without saying that a nation, like every historical phenomenon, is subject to the law of change, has its history, its beginning and end.

https://www.marxists.org/reference/archive/stalin/works/1913/03a.htm