This is traditional behaviour for Moscow. They were doing it long before Bolshevism, and will continue to do it forever.
Prison in the Gulags is actually considered leniency. Usually they just throw political opponents out of tenth-story windows. Or Novichok them if they're in foreign countries.
Yes, even during the time of the Czars, they were trying to expand. The way I heard it, was that they knew their borders could not be defended well, so they just expanded them. I don’t agree with that thinking, but that was their idea.
You’ve hit on the key point here. We’re dealing with a diseased culture and society that has no interest in reform. Tsarism, Communism, Putinism. Russian chauvinism in its various historical flavors always makes Russians serfs and slaves to their Kremlin. It’s their fate, sadly.