150 years doesn’t change the moral validity of the claims. When America evacuates Texas and California we can discuss Russia leaving Donetsk. For that matter they have historical claims on the Ukraine as a whole. The Kyiv Rus founded Russia in Kiev - now Ukraine. Maybe Ukraine owns Russia. Maybe the other way around. We can argue in circles but Donetsk isn’t going back to Kyiv, ever.
The bottom line is it doesn’t involve America or the West. Stay out of it and face down China before the tranny American military is sent to the bottom of the South China Sea.
150 years does change the situation. What was done in the 1800s is no longer statecraft in the modern world.
The Kyiv Rus didn’t “found russia”.
Kievan rus was a group of city states that were ruled by the rurikid family.
By your logic all of Russia and Ukraine should belong to Mongolia