In Starship Troopers, the motive of the humans to attack the Klendathu planet is that the "bugs" inhabitants of that planet allegedly launched a meteorite at Earth that destroyed Buenos Aires. The only evidence given is that the meteorites apparently originated in the Klendathu region of space.
But this seems a bit implausible, the bugs are never shown to do it or even to have the capability of doing it, the rocks are travelling very slowly and would surely take thousands of years to reach Earth (as well as needing amazingly good aim), and in one scene the possibility the bugs would prefer a "live-and-let-live" policy is suggested. In fact, aside from a news report and some of the characters making the claim, there is no evidence offered that it was an attack on Earth by the bugs.
Furthermore, the society is portrayed or satirised as a sort neo-fascist one, and one might not put it past the government to lie about it.
So are we, the viewers, supposed to doubt that it was a deliberate attack by the bugs or are we supposed to take that report at face value?