Heinlein's philosophy on responsibility, liberty, force, government, etc. is probably no better written than it is in Starship Troopers.
Remember the scene in the movie where one of the characters asked Sgt. Zim why we didn't just nuke the enemy from orbit?
Ace Levy: Sir, I don't understand. Who needs a knife in a nuke fight anyway? All you gotta do is push a button, sir.
Sgt Zim: Cease fire. Put your hand on that wall trooper. PUT YOUR HAND ON THAT WALL!
[Zim throws a knife and hits Ace's hand pinning it to the wall]
Sgt Zim: The enemy can not push a button... if you disable his hand. Medic!
That was pure bullsh*t and in no way reflects the real philosophy from the book. Here's the book version:
If we can use an H-bomb--and as you said it's no checker game; it's real, it's war and nobody is fooling around--isn't it sort of ridiculous to go crawling around in the weeds, throwing knives and maybe getting yourself killed . . . and even losing the war . . . when you've got a real weapon you can use to win? What's the point in a whole lot of men risking their lives with obsolete weapons when one professor type can do so much more just by pushing a button?
Zim didn't answer at once, which wasn't like him at all. Then he said softly, 'Are you happy in the Infantry, Hendrick? You can resign, you know.'
Hendrick muttered something; Zim said, 'Speak up!'
I'm not itching to resign, sir. I'm going to sweat out my term.
I see. Well, the question you asked is one that a sergeant isn't really qualified to answer . . . and one that you shouldn't ask me. You're supposed to know the answer before you join up. Or you should. Did your school have a course in History and Moral Philosophy?
What? Sure--yes, sir.
Then you've heard the answer. But I'll give you my own--unofficial--views on it. If you wanted to teach a baby a lesson, would you cuts its head off?
Why . . . no, sir!
Of course not. You'd paddle it. There can be circumstances when it's just as foolish to hit an enemy with an H-Bomb as it would be to spank a baby with an ax. War is not violence and killing, pure and simple; war is controlled violence, for a purpose. The purpose of war is to support your government's decisions by force. The purpose is never to kill the enemy just to be killing him . . . but to make him do what you want him to do. Not killing . . . but controlled and purposeful violence. But it's not your business or mine to decide the purpose of the control. It's never a soldier's business to decide when or where or how--or why--he fights; that belongs to the statesmen and the generals. The statesmen decide why and how much; the generals take it from there and tell us where and when and how. We supply the violence; other people--"older and wiser heads," as they say--supply the control. Which is as it should be. That's the best answer I can give you. If it doesn't satisfy you, I'll get you a chit to go talk to the regimental commander. If he can't convince you--then go home and be a civilian! Because in that case you will certainly never make a soldier.
OBVIOUSLY it's difficult to translate a book into a movie...but recent years have proven this not to be impossible. What Hollywood wanted to do was translate this particular memorable scene in the book (to anybody who has actually read Starship Troopers) into a catchy action scene in the movie. What they did NOT want to do was translate the real meaning behind the use of force, of any kind, as legitimate beyond the scope of the movie's theme of man-against-alien-monsters for survival.
The movie is all about man-against-alien-monsters. The book, however, is about the long term survival of man-against-man with the stark realities of human behavior plainly stated...set against the background of man-against-alien-monsters.