Moscow murdered millions of Ukrainians in 1933 and before that when Troskys Red Army ravaged the country after the Communists murdered the Czar and took over Russia.
https://www.youtube.com/watch?v=PsM3YoPiloE
Yeah back in the USSR they did.
But the modern borders of Ukraine the US defends are the Ukrainian borders as defined by the murderous USSR (Soviet Union).
Russia isn’t the Communist Soviet Union.