There are, of course, chapters in history books dedicated to the subject, yet few films. Simple reasoning shows the problem inherent in placing social commentary within films during this time period. Anyone speaking critically of the scare tactics used by Joseph McCarthy was likely to be next in his sights. In fact, the writer of Invasion of the Body Snatchers, Daniel Mainwaring, was on the infamous Hollywood blacklist prior to writing the screenplay for Invasion. While McCarthyism was effectively over by 1954, two years before the date of Invasion of the Body Snatchers, directed by Don Siegle, the Red Scare that McCarthy originally exploited was still lingering in people's minds.
This leaves the movie makers with few tools with which to express themselves, though many writers found ways. Playwright Author Miller used metaphor when writing The Crucible before he was targeted by McCarthy, yet the most popular of the literary styles used seems to be satire.
The satire found within the Invasion of the Body Snatchers is evident only after the first third of the movie, once the main character, Dr. Bennell (Kevin McCarthy) becomes paranoid that the people around him are some of "them." His paranoia escalates to the point where, in the original script, he is left screaming in the middle of a freeway (the psychiatric ward scenes were added later when the studio wanted a happier ending). The paranoia shown on screen can also be said to show McCarthy's personal and public unraveling after the Army-McCarthy hearings and Edward R. Murrow's See It Now documentary aired on television in 1954.
Satire has long been used to show people their own follies, and in this case it is no different. After the red scare in the mid 1900's, there was no real record or public memory of what the fear does to society. With the readiness of media concerning McCarthyism available to everyone in the form of movies, such as Invasion of the Body Snatchers, it is unlikely that people will forget what has happened in the past for very long.