I couldn't think of any other subreddit to post this in. I'm reading Howard Zinn's A People's History of The United States and just came across this:
"A documentary film on the arms race made in Canada was forbidden to enter the country by the Reagan administration, but a federal court ordered it admitted."
He doesn't mention the title, and after several google searches,I can't find anything on it.
You might be thinking of If You Love This Planet - a 1982 film by the National Film Board of Canada and Dr. Helen Caldicott. The film was categorized as political propaganda, due to its unequivocal criticisms of nuclear policy and the proliferation of nuclear weapons.