I guess there was a stain of McCarthyism in Britain as well, but never the witch hunt that occured in post war USA. Some of the beliefs of people trying to improve the lot of the working poor were not so loathsome at all. Yes , the actions of both Hitler and Stalin were dispicable but wasn't Stalin on our side in the war?
Neither Britain or the USA really feared the violent invasion of their country from Russia. What they feared most was that the wealthy and powerful may have share with the less fortunate, through democratic implimtation of socialism. Of course this threat was from within, so many governments spied on their own citizens, especially those who had any kind of following. (musical or other)