Consider the following:
- Major premise: All weapons are made to be used.
- Minor premise: All humans are prone to using weapons.
- Conclusion: All weapons will be used.
- Consequent: I'd better do it first.
A subtrope of I Did What I Had to Do, this is a stock explanation for those operating on the extremely cynical end of the Sliding Scale of Idealism vs. Cynicism. When such characters have to employ a morally dubious weapon but still care about justifying it, this will almost always be the go-to rationalization. The argument goes that once a weapon has been invented it will inevitably proliferate and be used, and therefore the only sane response is to use it as early and often as possible. Expect to hear it as a paper-thin excuse from General Ripper, the Well-Intentioned Extremist, or The Social Darwinist as they sprint gleefully towards the Moral Event Horizon with the rest of the world in tow. If your heroes are using this justification, you probably live in a Crapsack World, a world of Black and Gray Morality at the least or Protagonist-Centered Morality at the worst.
The title is, of course, a common subversion of The Golden Rule.
- Kanako from Star Driver uses this as her justification for working with Crux and fighting Takuto.
- The warring sides of Mobile Suit Gundam SEED use this trope as justification for their deeds; both are led by extremists who aim for nothing less than the complete annihilation of the other side down to the last man, woman and child. Therefore, backing down and depending on Mutually Assured Destruction is equivalent to surrender. Things escalate when both sides acquire N-Jammer Canceller technology and a battle ensues where the Federation launches dozens of nukes at ZAFT's civilian population while ZAFT have a nuclear-powered Wave Motion Gun pointed at Earth; had The Three Ships Alliance failed to destroy these WMDs, the result would've been a Mutual Kill. Fortunately, the extremists are killed during the battle, after which both sides have a Heel Realization and finally begin negotiations.
- One has to consider the additional fact that both the Federation and ZAFT were being manipulated by Rau Le Creuset who believed the war can only be stopped for good by having the two mutually annihilate each other, thus rendering humanity extinct and unable to war among themselves just for the sake of being different from each other. In other words, the spoiler character was invoking this trope.
- In the X-Men comics, one of Magneto's main rationales in his war on humanity is an assumption that humans will inevitably enslave/exterminate/oppress mutants unless mutants do the same to them first (or at least separate themselves from humans). It's one of the main sticking points in his philosophical differences with the more idealistic Professor Xavier.
- Hellblazer: When John Constantine was hired by a corrupt adviser to the Royal Family to discreetly resolve some demon business, his anarchist friend tried to warn him that they'll betray him as soon as his work is done. John is not unaware of the possibility, and reassures his friend that he will follow his usual strategy: "Screw them before they screw me."
- Played for Laughs in a Baby Blues strip, wherein Wanda catches Zoe putting salt in Hammie's milk. Zoe defends her actions saying that she is following the Golden Rule: "Do unto brothers before they do unto you." Wanda suggests they read the real Golden Rule again.
- Quoted almost verbatim by Leaf in Pokémon: Clefairy Tales one time she commanded her Rattata to use Quick Attack.
Leaf: Do unto the other guy before he does unto you!
- The infamous General Ripper from Dr. Strangelove gives this excuse, claiming he's giving the US "the best kind of head start."
- The explanation for the construction and deployment of DESTINI in The Core: "Someone was going to build it, so we built it first."
- Said word for word in Van Helsing, with Dracula starting and Igor finishing the quote. However, they were talking about generally being horrible to people rather than a particular plan or pre-emptive strike.
- According to The Men Who Stare at Goats, both sides of the Cold War ended up doing psychic research because, even though not many people on either side actually believed there was anything in it, they couldn't let the other side lead the field just in case it turned out to be real.
- In the Bad Future the protagonist of Paycheck is trying to prevent, a machine capable of seeing into the future predicts a nuclear war. So the US decides to strike first, starting said war.
- In The Dark Knight, the Joker attempts to set up this kind of scenario with two barges, one filled with ordinary civilians and the other with criminals. They are each given a detonator and the same instructions: Blow up the other boat before they blow up you, and if neither boat blows up within a certain time limit, then he'll blow them both up himself. Neither group plays along with the Joker's game.
- Magneto's motive in some X-Men movies. In X2: X-Men United and X-Men: First Class it's quite clearly "do unto them what they just tried to do to us, so they don't get another shot at it". In X2 this involves a weaponized version of Cerebro; in First Class it involves a ton of missiles fired by US and Soviet fleets.
- In the 1950s St. Trinian's movies, the school song contains the lines:
Let our motto be broadcast, "Get your blow in first"
She who draws her sword last always comes off worst!
- The Pluckans trancklucate their unnamed sister planet in Kin-Dza-Dza! "so that they don't do that to us". Wef and Bi, who are from that exact planet, seem to be fine with that, because their people did plan to do the same for the sole reason of "because fuck you", and they are being good sports to the winners:
Gedevan: Why did they do it?
Wef: So that we don't do it to them first.
Gedevan: And why would you do that?
Wef: So that they don't hang over our heads.
- Starship Troopers: Both sides see the other as a hideous horde of insane vermin, who hate everything their very genes stand for (humans represent arrogance and infighting, bugs represent obedience and gluttony) and will do anything they can to wipe the other side out. Fancy that.
- In Dragon Bones, Ward comforts himself with this after killing a mere boy, telling himself that the boy was a bandit who would have killed him without a second thought if he had had the chance.
- This trope is the very basis of Ender's Game by Orson Scott Card. Instead of preparing for another alien invasion, mankind chooses to attack first this time.
- This is explored in Ender's Shadow, where Bean figures this out by attempting to postulate how Earth might prepare for the Third Invasion. Through a series of logical steps, he realizes that there is no way to adequately protect a planet in three-dimensional space, since all the Formics would have to do was get a single ship past the human blockade to lay waste to Earth. Therefore, an all-out attack is the only logical option.
- Subverted in the H.I.V.E. Series. The big Council 'O Evil's policy is "Do unto others." Yeah, that's the entire motto.
- In Larry Niven's Known Space stories, the ARM ("Amalgamated Regional Militia," the police force of the United Nations) exists primarily to stop this sort of thing from happening.
- Occurs in the Robert A. Heinlein short story "Solution Unsatisfactory". One of the U.S. characters considers having everyone who knows about the secret of the radioactive dust shot, but decides that the enemies of the U.S. would eventually discover it and use it against the U.S. anyway. The U.S. goes ahead with creating and using the dust itself.
- In Alexander Zorich's Tomorrow War, this trope is a bitter discovery for heroes. They believed they were defending Earth against an unprovoked Concordian invasion, but it turns out the Earth prepared invasion as well, and Concordians only managed to fire first, 'cause they were better prepared.
- In the novel The Killing Star by Charles Pellegrino and George Zebrowski, the aliens use this as a motive to wipe out humanity.
- The third, unnamed Entian power in Stanisław Lem's Observation On The Spot was attacked by both Lusanians and Kurdlandians for the fear of them getting hit by the Depopulation Bomb they've got rumors of (or were developing themselves, it's somewhat unclear). Poor southerners never stood a chance, though the reader is left with the impression that they indeed planned to do the same to their northern counterparts. Interestingly, even the fact that the third power existed is suppressed in both countries.
- This is the tenor of "Dark Forest theory" in The Three-Body Problem: with a finite amount of universe and little chance to develop trust, any species is a threat, and that means any species exposing its existence is a target.
- In The Lost Fleet, this is pretty much the Bear-Cows' philosophy. While looking like cute teddy bears with some bovine features, they also prove that herbivore does not mean harmless. Their "herd first" mentality is taken to the extreme. They have exterminated every predator and potential rival species from their home planet and are determined to do the same in space. Even if someone is not a predator (whom they attack on sight), they are still a potential rival for resources, who may one day attack. Therefore, the Bear-Cows will wipe them out first.
- Dollhouse: Used when Rossum's founder makes a last ditch effort to convince his "family" that he needs to mind control the world. Adelle DeWitt, not above morally dubious actions herself, calls him "spectacularly insane".
- In Firefly, one of Jayne's lines includes the phrase "I'll kill a man in a fair fight...or if I think he's going to start a fair fight," though he then goes on to list a few other possible reasons.
- Max on Living Single.
"It's not revenge; it's prevenge. Getting to them before they get to you."
- This was Season 3 of Star Trek: Enterprise in a nutshell, until the humans found out both sides were being played by the Sphere-Builders.
- An episode of Bonanza had a family of squatters led by a matriarch who claimed no one would give them a fair deal, saying there were two laws, one to protect everyone else and their law which was essentially "An Eye For An Eye." Their conflict with the Cartwrights starts when one of the boys kills one of her sons in self defense after he tried to shoot him in the back, twice, when the Cartwright tried to stop him from setting a clearing fire that would have burned an entire populated valley. Despite their stance of avenging slights the family acts in a way that actually causes confrontations, like squatting on other's land and breaking out rifles every time they meet someone. The matriarch's attitude has caused her sons to act violently when opposed and made it a Self-Fulfilling Prophecy, though most of her children don't agree with her position. In the end, her surviving children refuse to go to war with the Cartwrights and she decides to make peace with the family, ending the feud on a positive note as she accepts Ben's offer to help her family settle in a new home.
- In episode 7 of Survivor: Blood vs. Water, Tina reveals to Monica that Kat wants Monica to be voted out, which would clearly break the Galang women's alliance. Monica has a grim realization:
Monica: I teach my kids "do unto others as you would want them to do unto you"... but you know what? In Survivor, I figured it out: it's "do unto others before they do unto you".
- In Hill Street Blues, Sgt. Yablonsky would dismiss the police day watch with the above phrase almost exactly. "Let's do it to them before they do it to us." If it wasn't for Captain Furillo riding herd on Lt. Hunter and keeping his "destroy the village to save the village" tendencies in check, the entire police force would have become what Joyce Davenport sardonically referred to the police as: a Nazi occupation force.
- Played for Laughs on The Red Green Show in which Mike Hamar (a career criminal) tries to pass this off as a biblical quote, told to him by his (one of his) father(s).
Red: I don't remember that in the King James version. Maybe the Jesse James version.
Mike: Well, all I know is that my father was a clergyman, because he was a drummer in a Judas Priest tribute band.
- In an episode of 7Days, a rogue admiral wanted to start a war with China before "the red dragon awakens" and was willing to get himself and the crew of an American destroyer killed to do that. Fortunately, Parker manages to get the President on the line, who countermands the Admiral's orders.
- An episode of NCIS has a crazed engineer convince a submarine crewman that the US needs to start a preemptive war with Russia before the latter becomes too dangerous. They fake attack orders for the submarine captain and make sure the orders couldn't be countermanded. Fortunately, NCIS agents manage to stop them before they launch torpedoes at Russian warships. Then again, Pentagon was about to sink the sub, just in case. Even then, the arrested crewmember keeps screaming that if "we don't attack, we'll all die".
- In The Elder Scrolls III: Morrowind, the Thieves' Guild in general and especially Master Thief Gentleman Jim Stacey are normally violence averse. Despite their best efforts to bribe and/or blackmail their rivals in the Camonna Tong, they are forced to kill members of other factions that are planning to kill Stacey or other members of the Guild.
- The Zero Escape series revolves around several Deadly Games. Naturally, even heroic participants are worried by the fact that their 'opponents' could easily betray them if left alive. Given that several murderers are also participating, there are actually times when killing someone is the right and sensible decision. Not shooting Eric in Zero Time Dilemma, for example, will lead to a bad ending where he fatally shoots the protagonist.
- Rick and Morty: in "A Rickle In Time", Rick and his grand-kids are split into two timelines. He attempts to fix the issue by merging their timelines back together, but runs into a snag, and immediately assumes that this means the other Rick gave up on merging and has moved on to try and kill the other, motivating both Ricks to actively try and kill the other before they themselves are killed.
- This line of thinking underpinned much of the nuclear proliferation in the Cold War. While nuclear weapons (utilising nuclear fission) were still weak, to the point that it would take half a dozen of the USA's stock of just 500 to completely destroy cities such as Shanghai or Warsaw outright (though the firestorms generated would have been largely sufficient even in the event of a single strike), certain US generals such as MacArthur talked openly about nuking the Commies into submission. Of course, the Soviet Union's invention and mass-production of the thousand-fold more powerful nuclear fusion ('hydrogen') devices and ICBMs in the early 1960s changed all that.
- First two and only uses of Nuclear Bombs in warfare were deployed because of this trope. The United States knew that Japan would fight to the last man, woman, and child to defend the home islands and did not like the prospect of invasion that would have to be done to win the war. Casualties were expected to be some of the costliest in American History. (Fun Fact: About Half a million Purple Hearts, an award given to US military personnel for injuries sustained from enemy combat, were ordered in anticipation. As one historian put it, they were the best war surplus. The United States would not need to place another order for the decoration until 2000! Even then, the original WWII era medals are still given out... the country is just getting close to running out of them half a century later.). Needless to say, Truman recognized that there would be a lot of American troops killing Japanese civilians and vice versa and he had an advantage that could kill more of them before they killed his own.
- The entire reason the Soviet Union even sought a Nuclear Bomb was because the only people who had one at that time were people who were aggressively opposed to their political style. It didn't help that America had used Nukes in the past, and did threaten a first strike whereas the Soviet Union maintained Second-Strike Only policies (and meant them, not that the Americans knew that at the time).
- A serious debate in the Soviet 1970s was whether or not it was best to nuke the PRC's atomic and rocket research facilities, since many argued that an escalation of the Sino-Soviet border skirmishes into a Total War was basically inevitable: the Chinese were crazy, they said (with some justification, as the Cultural Revolution was ongoing), and would never again accept 'peaceful co-existence' because it constituted acceptance of the heretical doctrine of 'Soviet Revisionism' (i.e. administration of the country by bureaucrats and not 'the people' themselves) and thus an end to Mao's much-vaunted 'Perpetual Revolution'. Therefore, the Chinese had to be nuked and they had to be nuked now before they got their hands on nukes capable of reaching the European republics of the USSR. Initially, cooler heads prevailed as it was hard to counter the incredibly obvious point that the quickest way to start a Total War with China was by nuking them. But as the Cultural Revolution, the Chinese nuclear program, and the border skirmishes all escalated the Soviets eventually agreed that they really were on a course to Total War and something had to be done. Accordingly, they merely threatened to nuke the PRC's research facilities if they refused to negotiate an end to the border skirmishes (while accepting the Chinese development of nuclear weapons in principle). Which they did, ushering in Sino-Soviet Détente.
- It was Hitler's favourite excuse for invading countries. Soviet Union also loved using this excuse. Some Wehrmacht fanboys and German nationalists still, to this day, follow the official line of Nazi Germany: that the Jewish puppetmasters controlling the Soviet Union were going to make it invade Germany and then exterminate all European people (because the superior intellect and morality inherent to European races made them the only ones capable of resisting Jewish manipulation). Do Unto Others Before They Do Unto Us was invoked to morally justify the war.
- "Anyone who has ever looked into the face of a Red commissar knows what the Bolsheviks are. There is no need here for theoretical reflections. It would be an insult to animals if one were to call the features of these, largely Jewish, tormentors of people beasts. They are the embodiment of the infernal, of the personified insane hatred of everything that is noble in humanity. In the shape of these commissars we witness the revolt of the subhuman against noble blood. The masses whom they are driving to their deaths with every means of icy terror and lunatic incitement would have brought about an end of all meaningful life, had the incursion not been prevented at the last moment" - German Army Information Pamphlet
- "The battle against these subhumans, who've been whipped into a frenzy by the Jews, was not only necessary but came in the nick of time. Our Führer has saved Europe from certain chaos." - German Army gunner Karl Fuchs, letter written 4th August 1941 (translated by Horst Fuchs Richardson)
- "What the Asiatic hordes would not have wrecked, would have been annihilated by Jewish hatred and revenge." - German Army Captain E.P., letter written 15th February 1943 (translated by Stephen G. Fritz)
- Interestingly, although German propaganda was fairly clear on the point that Judeo-Bolshevik overlordship would be replaced by German rule, no mention was made of the German authorities' genocidal plans for the region's non-Jewish population. note This allowed German military personnel to feel not just that they were waging a defensive war of liberation, but that they were fighting to stop genocide:
- "Now I know first hand what war really means. I also know however that we are forced into this struggle against the Soviet Union. For God have mercy on us, for if we had waited, or if these beasts had come to us. For them the most gruesome death is too beautiful. I am fortunate, therefore, that I should be here to put a stop to the handiwork of this genocidal system [völkervernichtenden]" — German Army private Frederich Fallnbigl, letter written July 1941 note
- Another interesting point relating to the Conspiracy Theory that papa Stalin was about to invade Germany: when The Holocaust became popular knowledge in the 1960s some of those groups switched to a "Stalin-Bolshevik" model. The last popular scholar to advance the view that the Soviet Union was about to attack Germany was the Soviet defector Victor Suvorov, who in the 1970s used circumstantial evidence hinting at Soviet plans to counter-attack the Germans on the borders of the Soviet Union and drive them back into Germany when the war began as 'proof' that the Soviet Union was going to declare war on Germany. Direct examination of the actual plans in the 1990s revealed the true nature of the planned operation, a defensive counter-offensive. note
- Seeing that papa Stalin did break the alliance he had with the Reich at the first opportunity it became profitable...
- This is a popular theory for why people allowed the commons in medieval England to be overgrazed. "If I cut back and give the fields time to recover then someone else will just come along and overgraze the field anyways. They'll have better fed cattle and I'll be cut off from a free resource." And that was a real tragedy.
- Second and Third Punic Wars were largely the result of both Carthaginians and Romans fearing a future invasion from one another. The second one was started when it became clear to Carthage that Romans weren't going to tolerate their territorial expansions in Iberia for any longer. The third one on the other hand started when what little remained of Carthage after the devastation of the second war was getting back on its legs. Romans started to fear that they might become a threat once again and decided to annihilate the entire Carthaginian population.
- This is the sort of reasoning that Thomas Hobbes feared would dominate people's actions in the absence of an all-powerful ruler whom none could overpower (making it downright suicidal to shoot first, last, or ever). He thought that even genuinely good-natured people would be motivated by worries that their neighbors might not be equally peaceable, leading them to kill lest they be killed (though it should be noted that Hobbes believed most humans didn't need this excuse).