Uh, because they are all within one nation. They identify as Ukrainians.
You could transmute your statement to any other nation and it would be the same. Why do the people in Archangelsk fight for Moscow? Why do the people in Wichita fight for Washington?
Tribalism is an innate feature of the human experience.
Despite Taiwan’s charter stating very clearly that they are the rightful government of China, the people there identify as Taiwanese.
Oh, oops, I don’t think I’m supposed to find contradictions.
Wow, you’re right! You have found the one chink in my armor that completely tears down my statement!
The Romanovs must all be British now.
The Dalai Lama must be American.
Lana Peters is Russian. So are all Ukrainians and Tatars that were forced to migrate.
Pack it up folks, by the decree of Nekandro, you can never be part of multiple tribes or switch ever!