->''"We have to face the facts, the technology exists. It can't be uninvented. Once it gets out there, it will be abused. None of us can prevent that from happening. But we can choose, where we want to be and on what side when the end finally does arrive. Do you want to be the destroyed? Or the destroyers?"''
-->-- '''[[spoiler:Boyd Langton]]''', ''{{Dollhouse}}''

Consider the following:

* Major premise: [[WhenAllYouHaveIsAHammer All weapons are made to be used.]]
* Minor premise: [[HumansAreBastards All humans are bastards.]]
* Conclusion: [[InYourNatureToDestroyYourselves All weapons will be used]].
* Consequent: [[MightMakesRight I'd better]] [[SelfFulfillingProphecy do it first]].

A subtrope of IDidWhatIHadToDo, this is a stock explanation for those operating on the extremely cynical end of the SlidingScaleOfIdealismVersusCynicism. When such characters have to employ a morally dubious weapon but [[PretextForWar 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 GeneralRipper, the WellIntentionedExtremist, or the SocialDarwinist as they sprint gleefully towards the MoralEventHorizon with the rest of the world in tow. If your ''protagonists'' are using this justification, you probably live in a CrapsackWorld, a world of BlackAndGrayMorality at the least or ProtagonistCenteredMorality at the worst.

The title is, of course, a common subversion of TheGoldenRule.
* Kanako from StarDriver uses this as her justification for working with Crux and fighting Takuto.
* The warring sides of ''{{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 MutuallyAssuredDestruction is equivalent to surrender. Things escalate when both sides aquire 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 WaveMotionGun pointed at Earth; had the protagonists failed to destroy these [=WMDs=], the result would've been a MutualKill. Fortunately, the extremists are killed during the battle, after which both sides have a HeelRealization and ''[[WarIsHell finally]]'' begin negotiations.
** One has to consider however the fact that both the Federation and ZAFT were being manipulated by [[spoiler:Rau Le Creuset]] who believed the war can only be stopped for good by [[OmnicidalManiac 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 the ''ComicBook/XMen'' comics, this is one of ComicBook/{{Magneto}}'s main rationales in his war on humanity, and one of the main sticking points in his philosophical differences with the more idealistic Professor Xavier.
* When [[Comicbook/{{Hellblazer}} 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 [[YouHaveOutlivedYourUsefulness as soon as his work is done.]] John is [[GenreSavvy not unaware]] of the possibility, and reassures his friend that he will follow his usual strategy: "Screw them before they screw me."

* The infamous GeneralRipper from ''DrStrangelove'' 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 ''Film/TheCore'': "''Someone'' was going to build it, so we built it first."
* Said word for word in ''Film/VanHelsing'', 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 TheMenWhoStareAtGoats, (which claims that this entry should be under the RealLife section,) both sides of the Cold War ended up doing psychic research mainly because of this trope. 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. Explained by [[HeyItsThatGuy Colonel]] [[Film/{{Avatar}} Quaritch]] at about 0:41 in [[http://www.youtube.com/watch?v=Xvx4tQXpLaA&feature=related this video]]
* In the BadFuture the protagonist of ''{{Paycheck}}'' is trying to prevent, a machine capable of seeing into the future predicts a nuclear war. [[SelfFulfillingProphecy So the US decides to strike first,]] [[GenreBlind starting said war]].
* In ''Film/TheDarkKnight'', the Joker attempts to set up this kind of scenario with two barges, one filled with ordinary civilians and the other with criminals, with the same premise: give them a choice to blow up the other group before they blow up yours. [[RousseauWasRight Neither group plays along with the Joker's game]].
* Magneto's motive in some ''Film/XMen'' movies. In ''X2'' and ''Film/XMenFirstClass'' 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 an US and Soviet fleet.

* ''Series/{{Dollhouse}}'' - Used when Rossum's founder makes a last ditch effort to convince his [[strike:pawns]] ''family'' that he needs to [[MassHypnosis mind control the world]].
* In ''Series/{{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 ''LivingSingle''.
--> "It's not revenge; it's prevenge. Getting to them before they get to you."
* This was Season 3 of ''Series/StarTrekEnterprise'' in a nutshell, until the humans found out both sides were being played by the [[LetsYouAndHimFight Sphere-Builders.]]
* An episode of ''{{Series/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 SelfFulfillingProphecy, though most of her children don't agree with her position. In the end, [[spoiler: 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 ''{{Series/Survivor}}'': Blood vs. Water, [[spoiler: 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:]]
--> [[spoiler: '''Monica''': I teach my kids "[[TheGoldenRule do unto others as you would want them to do unto you]]"... but you know what? In ''{{Series/Survivor}}'', I figured it out: it's "do unto others ''before'' they do unto you".]]
* In Series/HillStreetBlues, 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 him from starting World War III at every chance, the entire police force would have become what Joyce Davenport sardonically referred to the police as: a Nazi occupation force.

* In ''Literature/DragonBones'', 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 ''Literature/EndersGame'' by OrsonScottCard. Instead of preparing to another "bugs'" invasion, mankind chooses to attack first this time.
* Subverted in the ''Literature/HIVESeries''. The big Council 'O Evil's policy is "Do unto others." Yeah, that's the entire motto.
* In Creator/LarryNiven's ''Literature/KnownSpace'' 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 Creator/RobertAHeinlein 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 [[spoiler:the Earth prepared invasion as well, and Concordians only ''managed to'' fire first, 'cause they were better prepared]].

[[AC:{{Real Life}}]]
* This line of thinking underpinned much of the nuclear proliferation in the Cold War, and certain generals like [=MacArthur=] talked publicly about preemptive nuclear strikes against the Communists. Thankfully, cooler heads prevailed on that one.
** In fact, that nuclear weapons have only been used ''once'' (or technically ''twice'' on both Nagasaki and Hiroshima) in warfare is a fairly solid refutation of the logic behind this trope (as described at the top of the page). Nuclear weapons were invented, proliferated amongst major world powers, but have never been used against an enemy since that first time demonstrated just how powerful they were.
* It was [[UsefulNotes/AdolfHitler Hitler's]] favourite excuse for invading countries, Russia in particular. There's even a ConspiracyTheory that Stalin wouldn't have tolerated the Nazis in his backyard for too long and was ready to strike them first. Very unlikely, though, given how unprepared Red Army actually was at the early stages of war.
** Its not just a conspiracy theory, as reputable academics have given that serious thought. The Soviet Union's industrial capacity was at least half again as much as that of Germany and her allies combined; Germany attacked because Hitler thought it was then-or-never. The typical conclusion is that no, Stalin wasn't planning to invade in 1941-2, but Stalin would almost certainly have done it when he felt the Red Army was ready. Which it certainly wasn't, in 1941.
*** Hitler 'thought' it was then-or-never. When given accurate reports of the Soviet Union's industrial capacity[[note]] They produced at least twice as much ''everything'' as Germany did at every stage of the war, with the exception of trucks and aircraft; the USSR 'only' produced 15% more aircraft of all types than Germany did[[/note]], he flat-out refused to believe them. German defeat was always inevitable because of the Soviets' ability to mobilise their people and produce war materiel; the Red Army's abysmal performance in the summer of '41[[note]] Largely the result of Stalin's failure to plan for such an invasion, and his insistence on keeping the Red Army camped 'right across' the border from Germany (like a total strategy-noob)[[/note]] only made the war 'look' like a close-run thing. In reality, capturing Moscow 'and' Leningrad 'and' Stalingrad[[note]] A total impossibility, but bear with us[[/note]] before October of '41, it still wouldn't have been enough to win. Taking territory is very different from holding onto it, and Soviet industrial capacity would still have remained largely undiminished. The only question on the Eastern Front was how long it would take, and how many people would die, before Germany fell. The answers would appear to be 'four years' and '28 million', respectively.
* 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 [[http://en.wikipedia.org/wiki/Tragedy_of_the_commons tragedy]].
* This is the sort of reasoning that [[HobbesWasRight 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 [[HumansAreBastards didn't need this excuse]]).
* This rationale was used to defend the Iraq War after it was found there were no nuclear weapons- the Iraqis would've eventually developed them anyway so a preemptive strike was necessary. [[FlameBait And nothing more needs to be said]]