Yup. And vice versa. Churchill, for example, simply despised Stalin and the Communists...until he had the Nazis to deal with. Then he dreamed of the day when Russia and the British Commonwealth would join hands in common cause, and on June 22nd, 1941 he got his wish. That was the day Hitler made the giant mistake of attacking Russia.

Churchill went right back to hating the Russians the moment Germany was out of the way. ;-) That's how it works in power politics.