Also read the book and then read any of Heinleins other books, the dude was a competent author and just kinda liked playing around with weird ideas like psychic sex cults and obviously fascistic protagonists.
It boggles my mind that people can treat Starship Troopers as proof of Heinlein sincerely promoting fascism when Stranger in a Strange Land was published immediately afterwards. Dude liked playing with ideas, it's not that complicated.