No he wasn’t and keep in mind he warned FDR about Stalinist Russia. In fact Churchill was known to abandon some freedom fighters that he deemed too Marxist. He was well aware that Russia was simply a convenient ally at the time, but was never comfortable with the West’s relationship with them.
Do you realize that Churchill was a guy who offered Stalin Eastern Europe and half of Germany in Tehran? Otherwise there was idea that he is not going to chase the Germans back to Berlin.
Also Churchill was strictly against the formation of Israel, believing that it is a communist plot.
And that is just a couple of his antics.