No different that us breaking off a chunk of Serbia and creating Kosovo, or breaking off a chunk of Syria and giving it to the Kurds.
We do the exact same thing, and then act shocked when others do the same.
What the US and Nato have done is radically different. We haven't claimed territory for ourselves, nor have we transplanted Americans en masse into territory we covet. Moscow does both. Has done for the last 500 years or so.