This is literally how countries are formed. Ukraine is made up of lands that never belonged to Ukrainians.
Discussion
I dont know the history of this part well enough to comment which land belongs to whom ..but my point was :
**never assume how a leader of a poerful people may react .. their compulsions (good or bad) are hard to predict for "normal" people ! .. Thus risk is super high **
countries are formed from the lands of neighboring states, and Ukraine is no exception. Literally half of the countries in Europe have illegally annexed something from each other.