Another unsung layer to this movie is just how well it ties into key influences on Heinlein prior to his writing the novel. The novel itself is heavily influen

Another unsung layer to this movie is just how well it ties into key influences on Heinlein prior to his writing the novel. The novel itself is heavily influenced by WWII wartime military and popular culture, and roots its social thought experiments in that context. The movie turns this into visual leverage, weaving together elements from WWII era propaganda films and Hollywood's subsequent decades of iconography of that era.