The spread of communism didnt start until 1949 and didnt come into play in Vietnam until 1950. The french started taking over Vietnam in 1945. So no the French were not there to stave the march of communism. They were there to rule over the vietnamese people.

I have no faith in human perfectability. I think that human exertion will have no appreciable effect upon humanity. Man is now only more active - not more happy - nor more wise, than he was 6000 years ago. Edgar Allan Poe