Starship Troopers novel would seem not to be a parody. Until, of course, you're old enough to recognize real irony and not Verhoeven's kindergarten monkey shit throwing.

Even Nazis and other fascists today are more often than not grotesque deliberately, using that as a protest or as some postmodernist distortion of symbolic language.

Heinlein there is not being grotesque, he describes an ideology and society built from all the right things, somehow devolved into military rule despite military people not being allowed to vote and take state posts until retired (meaning survival till retirement during perpetual galactic war), despite that society being libertarian and libertine and democratic and cosmopolitic to the extremes and despite the system having been instituted first and foremost to avoid war and fascism and civil violence. He literally shows fascism built on common anti-fascist tropes. Some usually directed at future (say, fear of another world war thrashing most of our world), but in his book already in the past.

While reading it you don't even understand that it was effectually fascism, that seems too simple and also the very thing it's not supposed to be. Militarism, society built on duty and all that - yes, fascism - not.

It's a very good book, more similar to Vacuum Flowers than it seems.