Science fiction movies in the 1950s often masked real fears and anxieties of the Cold War era. One of the common themes was a fear that technology would lead to the destruction of the planet.
The 1951 film The Day The Earth Stood Still is an example.
In the film, a spaceship lands in Washington, DC and the alien aboard has a dire message for mankind.
Earth's citizens learn that an interplanetary police force of invincible robots has been created. The robots have absolute power over everyone in matters of aggression. War is not allowed.
The final message of the film is that the choice for Earth is simple. Join the interplanetary community and live in peace or pursue humanity’s present course and face ruin.
The filmmakers made the film as believable as possible to drive home the core message against armed conflict in the real world.
UW’s American Heritage Center has the papers of the film's producer Julius Blaustein and other filmmakers in the science fiction genre.