So how do we define the geopolitically stable boundary between his world and our world and keep the peace between us? I am guessing keeping what is ours and coveting and horning in on what is his is not going to continue to be the winning strategy here.
What we know for certain is that Ukraine has been the stomping ground of conquering armies for 3000 years or longer. For the last 1000 years it has been taken over by Poles, Turks, Russians etc., most recently Russians.
Ukraine is considered neither European nor Asian. It's always been stuck in the middle belonging to no one. Other slavic countries were always considered separate, but definitely under the influence of Russia.