Joseph, if the United States had annexed Kosovo, your comparison would be valid. It’s one thing to support a breakaway or a coup, it’s another to annex the territory of a sovereign nation. It’s reminiscent of Sudetenland.
It’s obvious that Russian nationalists, including Putin, are trying to undo the breakup of the USSR. I don’t think they’ll be happy until the western former Soviet republics fall under their hegemony (I suspect they’re happy to get rid of the various Stans, since they’re predominantly Muslim).