Some of the footage of HUAC hearings includes a witness smoking, as, inevitably, is in the footage that appears of him.
Frightening & Intense Scenes
Unrated
Footage of nuclear explosions and of the malnourished Soviet sub crews 'quarantined' in 1962, and briefly-shown stills of Julius and Ethel Rosenberg in open caskets after their executions, are the most potentially distressing images.