Why did they kill *SPOILER*

In the beginning of the movie, Rasczak is teaching Rico that a citizen accepts personal responsibility to protect the body of politic, aka the system of government, aka Sky Marshal Dienes.

We later see Sky Marshal Dienes on that Arachnid outpost, hidden in the closet, as all the marines died protecting "the body politic". That is, everybody on that outpost died protecting that dude, who is only concerned with his own survival, at the expense of everybody else.

Then, at Dizzy's funeral, Rico states: I now understand what is the difference between a civilian and a citizen. A citizen has the courage to make the safety of the human race their personal responsibility

The idea is that Rico replaces "body politic" with "human race":
Sky Marshal Dienes is the "body politic"
Dizzy, Carmen, Rico's parents, the marines, the fleet, are the "human race". I'll get back to this at the end.


The satire in Starship Troopers is complex, but an easily observable idea is, that the "body politic", aka the Sky Marshals, the Establishment, the ruling class, the power that be, the government, sacrifices you, me, Rico, Dizzy, Carmen, Zander, Rasczak, Kitten Smith, everybody else, the entire human race, only to perpetuate themselves, the Establishment.

A deeper idea of the satire is, that the Establishment deceives you with the following ideology:
1. a Civilian has to serve in the army, to become a Citizen.
2. a Citizen has power.
3. but you can soon see that the army is always at war, and
4. you either die, or get maimed physically and emotionally, in war.

We never see the promise fulfilled. No character on screen, other than the upper echelons - who never go in combat, completes the process of going from Civilian to Citizen, and exercising political power.

The same happens in our contemporary western society. We are being deceived with propaganda, about how we as citizens have the political power and stuff. In reality, we don't have power, because power is taken, not given, as Rasczak explains in the very beginning of this movie.


Back to how the movie is designed, consider this:
Starship Troopers is a satire against the western, American establishment.
Starship Troopers is produced in America, subject to American censorship.

So, the movie has to be subversive, because the MPAA censors any movie that goes against the American Establishment. Every movie is watched by an MPAA censorship commission, prior to release in theaters. You'd get horrible ratings, most theaters would not play your movie, the studio would get raided by IRS and all sorts of inspections, all that is needed to intimidate you into censoring yourself.

So, Starship Troopers, is the result of the writer and director's ambition of telling the audiences the truth about our western system of oppression, and the need to go beneath the radar of the censorship.
Make the movie appear as pro-Establishment, while camouflaging a deeper message, that the mofos in the censorship commission would miss, as they're not 100% dedicated to their task.

So, Rico saying "a citizens makes the protection of the human race his responsibility", is most likely a negotiation by the writer and director, with the censorship commission. It sounds neutral and generic, although it marks a refusal of the mantra "a citizen makes the protection of the body politic his responsibility"
The entire movie is the result of this negotiation. It is meandering, confused, ambiguous, most people think of it as a mindless pro-government pro-war movie. That's because you can't get a pass with an anti-Establishment movie, in America.
Director Verhoeven soon found himself isolated in the industry, despite his movies making profit.


Through Rico, you are supposed to realize that the Establishment is destroying you, for their own benefit. You will lose your loved ones, you will lose parts of your body, and you will lose your own life, to perpetuate the system put in place by a bunch of psychos who are enjoying life in their luxurious villas, in idyllic country scenery, while we are crammed together in polluted cities, slaving our lives away, for them, in perpetual fear of the Arachnids, Terrorists, Muslims, Illegal Aliens, Commies, etc.