For a truly insightful look at America's pervasive "Red Scare" culture of the 1950s, one need look no further than Don Siegel's (original) 1956 "Invasion of the Body Snatchers", wherein the pod people are metaphors for the near universal fear of a "Godless, soulless" Communist takeover coming from within via sleeper agents born, raised, and trained to seamlessly blend in with American society (they look, talk, and seem just like us, but are alien and out to destroy us). Everything one needs to know about America's fear of Communism in the 1950s is contained in this film. This is Scifi at its very best, as social commentary as well as a potent art form and a valuable historical source.