The movie takes place in the Starcraft universe.The Bugs are obviously the Zerg. They found Earth, attacked it with an astroid, and caused humanity to go to war. The Brain bug could be a mobile version of a Cerebrate. When they capture the Brain bug, human psychics discover the concept of an Overmind, causing them to form the United Earth Directorate and track it down, which brings them to the part of space that Starcraft's main plot happens. The Protoss are not in the movies because they have Zerg to fight that are much closer to their own homeworlds.
The movie is Bug propaganda.It's too Anvilicious not to be.
The Bugs were genetically engineered by the military.At least in the movie & the various TV series, their physiology is too specialized & deliberate to have evolved naturally. It is also too similar to Earth insects to be alien. The Military created the creatures through bioengineering to create an eternal enemy for Earth to justify their continued stranglehold on the government.
The Bugs were genetically engineered by a corporation that does genetic engineering.Places like Monsanto have the exact right mix of long-term planning, ability to keep secrets, and absence of enlightened self-interest needed to pull off this sort of project. The end result of this project is a society in which almost no one is a citizen with voting rights — only people who have served, past tense, have the vote, and there are very few of those. The corporations in this society can steer the few people who are in charge to guide anyone who isn't in the military to outright hedonism, which is good for business and which is possible if the leadership is sufficiently far from Heinlein standards. Note that those seen outside the military are living in luxury if they have not been directly affected by a Bug attack.
Starship Troopers takes place in the Warhammer 40,000 universe
The asteroid destroying Buenos Aires was dropped by the military.Here is what happened: when the spaceship got hit by the asteroid, they wondered if the message they sent made it to earth in time to warn them. It DID make it to earth, but it should've taken years for the asteroid to make it there, since they were in deep space and nowhere near earth when they sent the message. So another section of the military sent out a ship, picked an asteroid, carried it past the defense forces, and dropped it on Buenos Aires. The destruction of a whole city and the death of thousands (that few?) is enough propaganda fuel to start a full scale war; and if anyone else picked up the message of the approaching asteroid, they'd have a justification. In fact, this can make EVERY asteroid attack pure propaganda fuel. There is no reasonable way to catapult them all the way across the galaxy to a specific planet because it would take millions of years. Asteroids should not go FTL.
The asteroid was a random act of nature.Earth just seized the opportunity to blame it on the Bugs.
The M.I.s suck because their doctrine was deliberately designed to make them suckThe entire war was a gigantic Wag The Dog gambit by the fascist government to rally the populace to them by giving them an enemy to be afraid of and hate, so they'd look to the fascist government for safety. The Arachnids were perfect for this purpose because they were technologically primitive and incapable of being any actual threat (the "Bug Meteoroids" were being secretly thrown at Earth by the fascist government - see previous WMG). However, the fascist government wanted to make them look like an actual threat to the populace, and this involved deliberately designing the weapons, tactics, doctrine, and training of the MI so they'd just barely be able to defeat the Arachnids, instead of utterly crushing them in a month like they would if they were actually fighting to win. Hence why the MI don't just kill the screaming hordes of Arachnids with machine guns and tanks and avoid all those unnecessary casualties.
The humans are controlled by another intelligent race - hyper-intelligent cowsWhen the in-movie news is talking about the bugs, they show a cow being eaten by a bug. However, the violence is censored. Immediately afterward, they follow it up with uncensored video of humans ripped limb from limb. The hyper-intelligent cows don't see too much of a problem with letting their non-intelligent kin get killed, but they'd rather not see it as it hits a bit too close to home. Combining this with some above theories, it becomes obvious that the hyper-intelligent cows genetically engineered the bugs, perhaps because their human servitors had reached the limit of their evolution and the hyper-intelligent cows wanted new minions, especially ones which are psychically pliable (did I mention that the hyper-intelligent cows are also psychics?).
The Movie was in-universe propogandaThat's why it's so over the top, why the good guys are seemingly in no pain at the end despite their injuries and walk away smiling and cheerful despite the massive death surrounding them. There are no "psychics", that's just to make humans seem like we have a cool advantage over the Bugs' Hive Mind. The classified details have been replaced with war-film cliches, and they used Hollywood Tactics exclusively because depictions of real-world military tactics are classified or even illegal in that totalitarian society in order to prevent potential rebels from learning to fight.
There are no Bugs.The asteroid was a natural event that the government needed to blame on someone (since they should have detected the rock and deflected it long before it hit). The events of the film are pure fiction, there was no military action taken at all— records were altered to make some of the people whose bodies were lost in the strike into "war heroes" who "joined up" after the "attack".
The Xenomorphs are the descendants of the Bugs.After losing their first war with Humans, they adapted. They got rid of the Brain Bug (which was clearly an idiot anyway). They developed a more streamlined shape somewhat similar to their foes (jaws, hands, bipedalism), acid blood for close defence, and a method of reproduction that involved using their enemies to their own advantage. Meanwhile, humanity spread further out into space until they had to use coldsleep chambers on long-range starships. Earth's world government dissolved into national governments; the resulting wars caused their military forces to re-acquire tactical skills.
Neither the Bugs or the Federation sent the asteroidThe plasma bursts that blast the rocks out of Klendathu's orbit are natural phernomina like volcanos. So basicley the Federation wen't to war for nothing!
The film was made as a straight action filmStarship Troopers was actually meant to be a straight, campy action flick; it was only re-labelled as a parody when people pointed out that the film was an awful action film.
Birth control has been perfected for teens and STDs have been wiped out. People can choose to become reproductively viable when they feel they are ready.They certainly don't seem to mind teens sleeping around.
The Skinnies were manipulating both sides of the Bug War.The Skinnies, in an undoubtedly complex plan, got the 2 largest galactic empires (and thus, the 2 greatest threats against any plan concerning the galaxy) to go at each other. Once the Men and the Bugs destroy each other, the Skinnies will swoop in and "pick up the pieces". It doesn't matter who wins, the Skinnies will be the final winner.
Humanity is doomed.The clearest evidence of this is that, while the Federation is clearly a militaristic society, the government has imposed population controls by requiring people to get licenses in order to have children. It's easier to get one if you're a citizen, meaning that they attract people who want to have lots of children into a career where they're likely to get killed or maimed before they can. They treat their soldiers like expendable resources, and their training and tactics are virtually worthless. A combination of constant war dead without replacements being born means that humanity will wear itself out in a few decades.
Secretly, women are assigned according to their stature and toughness.The pretty, waifish girls get assigned to fleet (Carmen, and that blonde with her friends). Tough girls get put in Mobile Infantry (Dizz, etc). This is so the real beauties don't get killed in Mobile Infantry and are thus more likely to pass on their genes. Of course fleet's dangerous, too - but not as much front-line danger.
Katrina gets turned into the Hive Queen of the Brain Bugs.Katrina is the cute, redheaded, opera-singing trooper who admits, during the shower scene, that she only joined the Mobile Infantry because she wants to have children. In the Klendathu battle sequence, she's also the only soldier who we see giving into terror and running away; however, the ground opens up under her, and the last we see of her is when bugs are dragging her, screaming, into a tunnel. The bugs knew that she had maternal instincts and they accordingly subjected her to a supremely horrible Fate Worse than Death which transformed into a hybrid bug-human Hive Queen that gives birth to the Brain Bugs. How we do know? The Brain Bug that they capture is the only bug that shows fear, just as Katrina is the only trooper who displays real fear; and since it gives up its secrets to Carl, it can also be said to be the only bug that sings, just as Katrina sings opera when Rico is on the phone to Carmen.
There are far more Terrans than there are BugsAs seen in the films, the humans are prone to taking huge numbers of casualties in any fight (heck, in every film, it's rare for more than a handful of named characters to still be standing when the credits roll, nevermind the unnamed guys). While the humans do inflict significant casualties on the Bugs in return, the fact that they are able to carry on a years-long protracted war of attrition with them implies that the humans have a vast population base to dig into for "fresh meat for the grinder". Either the Bugs commit a relatively small portion of their numbers as Warriors (the rest being various worker types or whatever), or the humans significantly outnumber the Bugs.
The humans want the planets and are killing the bugs so there is no opposition for a takeover.Why else would the bug infested planets just conveniently have an atmosphere they can breathe on?
The humans have not fought a conventional war in generations.The reason the humans get slaughtered by the bugs is because their military is designed from the ground up to function as a civil police unit, not an interplanetary invasion force. Their lack of any armoured vehicles is because they were phased out decades or even centuries ago as being ineffecient for putting down rebellions or uprisings due to the military having complete air superiority in such scenarios anyway. The tactical doctrines that MI employs place emphasis on overwhelming lightly entrenched enemy positions with large numbers of highly mobile yet individually expendable troops, only deploying heavier weapons when absolutely necessary. These tactics and the technology that supports them have become so engrained in the military psyche after generations of success that their first encounters with the bugs ended in utter disaster. It is only after the initial horrific losses on Klendathu that the human military begin to research alternate tactics and appoint more free-thinking commanders capable of improvising on the scene instead of following established doctrine to the letter.
The entire wars real aim is to reduce population pressure on Earth.If you look at size of scale of the cities of earth, B. Aries, pop. some 20 million+, which probably rather typical and a lot of Earths cities are likely even larger and more densely populated. The size of the B.Aries buildings, the mega-scale ring surrounding the moon, and lastly the fact that births are licensed clearly indicate that the Federation has a problem. Even with population controls, white elephant mega-structures(aka job creation) and a relentless focus on hyper-militarism and competition,Earths leaders have been informed by their own experts unless something is done to relieve the population pressures and soon-Earth could well see wide-spread upheaval, regardless of how totalitarian the Federation is. When the Federation discovers the arachnids, a race of intelligent, but non-technological beings, the opportunity was too good to pass up. The Federation now has an 'out'. A way to wage war against an enemy that has no ability to threaten Earth or its colonies in any way, but are perfect fodder for fighting mass, WWI style campaigns on distant worlds using tactics and weapons that designed to lead to bloody tactical defeats and stalemates. For example, the 'Mobile Infantry' is a curiously I-Mobile infantry. Federation troops are so heavily conditioned it does not even occur for any to ask why they go everywhere on foot. Logistics issues aside, providing no transport or armored vehicles insures human troops are often ambushed with no vehicle protection or mobility of any kind. This again, helps maximize battlefield deaths. The war is intended to drag on for years, and inflict maximum casualties on the ground forces involved. This also helps with the population problem. Since women are totally integrated into all combat units, females killed in combat dont live to reproduce. The 'bug' war is very effective way to kill off breeding pairs in a way that is acceptable to the population at large. The average citizen thinks the war is being fought to 'win', when in fact, its real goals are to mobilize the population, avert a collapse on Earth, provide an outlet for repressed hyper-aggressiveness, and most importantly, to kill as many breeding age men and woman on the battlefield as is possible. As fast the Federation 'liberates' the barren, useless worlds they fight on, the Fed is transporting arachnids(via starships of course) to 'new' worlds to fight over. This helps explain why the Initial Invasion of Klendathu was such a failure-it was meant to be. The more casualties and losses-the better. The worst outcome@ 'Big K' would have been if the MI was actually able to win with low losses. Thankfully, the combination of the MI's inept tactics, poor gear, deliberate intelligence failures and bugs understandable effectiveness at defending their own homes provided the humiliating defeat the Federation needed, and indeed planned for. The 'defeat' at big K had no effect on Earth besides the loss of some mass-produced, low-quality gear and surplus males and females. Battlefield losses are of no consequence and easily replaced.