I remember reading the Heinlein and thinking how much he was influenced by ancient Greek civilization but the genius of the movie is how easy it is to twist all that high flown nonsense into this cartoon fascist fap fantasy.
No one was really being serious in this movie (although rumor has it that Denise Richards didn't really "get it" and was upset that people thought she was such a stupid character) and I never understood why it was so hard for people to grasp it. It's not some grand masterpiece, but Verhoeven and crew pretty much trolled Hollywood pretty good with this one.
Everyone should watch this movie with the Verhoeven/Neumeyer commentary track which is pretty entertaining. (not sure how common it is now, but it was featured on the 2-disc edition of the DVD that came out in the early 2000s)