The US set the precedent of changing borders with Kosovo. Russia just used skmething from their playbook. Russian government even said of US recognition of Kosovo that they are opening pandora's box.
The US set the precedent of changing borders with Kosovo.
The US did not attempt to annex Kosovo and admit it as a 51st state. I'm also not aware of any pronouncements from an American presidents in regard to "the historical unity of American and Kosovan peoples".