So Robert Wise's 1951 The Day the Earth Stood Still is one of my favorite movies, and I think it's a good example of how sensational, popular American films during the cold war, even a lot of major studio 50s sci fi, sometimes amounted to more than shallow vehicles for popular paranoia regarding external aggression, outsiders in our midst, commie infiltration, etc. Plain examples of the latter include two from 1956 -- Earth vs. The Flying Saucers and Invasion of the Body Snatchers -- and two from 1953 -- Invaders from Mars and George Pal's masterpiece War of the Worlds -- all technically and visually outstanding but ideologically transparent for the most part.
Alongside The Day the Earth Stood Still, which was widely regarded as subversive and even unpatriotic at the time (to the extent that the U.S. military refused to loan the film crew equipment and vehicles for the Ft. Meyer deployments), I'd include It Came from Outer Space (1953), featuring some of Ray Harryhausen's immortal visual effects work and a role-reversing story where the alien visitors are ultimately revealed to be benign, even supremely indifferent to humanity, and the hysterical Earthmen are shown to be dangerous and zombie-like in their xenophobia and reactionary violence. In that way, the movie anticipates a lot of the later attempts to turn the creature canon on its head (E.T., Close Encounters of the Third Kind, Starman, etc.), predating them by about 30 years.
Here's the trailer for It Came...
Notice that the trailer misleadingly suggests that the film is going to be just another by-the-numbers 'sinister alien threat' story. Probably a good index of how unusual it was for films like this not to play into that sort of narrative.
The whole thing used to be up on youtube to be seen for free by all (in standard format or 3-D!) but some lousy bastard removed it for copyright violation. Hair-splitting pricks!
In conclusion, I encourage you to secure a copy by any means necessary. It's not like it's rare. For upon the commencement of the theremin's stately tones -- with that space-age lifting of the theater curtain -- all my cares fall away and I'm born again in childlike wonder! Don't you want
to feel gratified for once in your miserable life? Aren't you worth that much, at least?