Primarily the Russian government's fault, but of course NATO is partly at fault. Belonging to NATO isn't a human right, and the expansion of NATO further east than Germany shouldn't have taken place. If European countries wanted a military alliance, they should have made their own. I don't believe I need to preface every comment saying "I wholeheartedly condemn the actions of the fascist Russian government in Ukraine", which I do, as much as I don't preface my comment saying "I wholeheartedly condemn the actions of NATO in Iraq", which I also do.