Special Bulletin is a 1983 made-for-tv mockumentary film about nuclear terrorism. I think of it as a science fiction film, but that's arguable. I remember this from when it first aired, and I was not nearly as impressed with it as I was Threads, though it was better received by others.
Googlevideo has it online:
DVDTalk calls it "One of the best and most unique television dramas of the 1980s". AMC and MSN have overviews.