The land doesn't belong to Russia. The Russian descendants there came from Russia in the last couple of centuries, they can't now kick out what's left of the natives and claim the land as Russian.Perhaps the Eastern Ukrainians and the people of Crimea don't want to be part of the original coup in Kiev ? They didn't have much say in the matter did they . Perhaps they asked for help from Moscow just like Kiev did with the EU and the US .
The Irish may not agree with you.One of the advantages we have of being an Island, is our historical borders do not change.