Which one? Russian or American?
blame? Putin can only be grateful to the Ukraine right nationalists (supported by West) who assaulted the foundational freedom of the Russian ethnic minority - the language - the very first thing after they took power in Euromaidan. While not having any real practical meaning, this assault was extremely symbolic and immediately provided popular support that Putin may have been lacking before. Crimea was basically handed over to Putin on the golden plate. It was so great for Putin that i sometimes wonder whether these right nationalists were paid Putin's agents :)