There was every possibility that Britain may have joined an anti-communist block as shown by the support given to Hitler by the many in the British establishment, based on a large part because of his anti-communist credentials.

The support for Hitler hung in the balance, in Britain, right upto 1940. If Hitler's intentions could have been shown to have been anti-communist rather than territorial (leaving aside ant-semitism because it was as rife in the upper classes in Britain), he may have had greater support. Even Churchill perceived Stalin to be a greater threat than Hitler until his wilderness years. He about-face on this issue, as far as I am concerned, was always more cynically political than conviction. His anti-Nazism didn't really start until post-Munich.

However, this is more debateable as regards France, where the communists had a greater power base in the French working classes, and the governments of the 1930s were to unstable to risk such a move.