Do Unto Others Before They Do Unto Us

""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?""

-, Dollhouse


 * Major premise: All weapons are made to be used.
 * Minor premise: All humans are bastards.
 * 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 Versus 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 protagonists are using this justification, you probably live in a Crapsack World, or at least a world of Black and Gray Morality.

The title is, of course, a common subversion of The Golden Rule.

Anime

 * Kanako from Star Driver 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 Complete Monster 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 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 Wave Motion Gun pointed at Earth; had the protagonists 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 however the fact that both the Federation and ZAFT were being manipulated by 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.

Comic Books

 * In the X-Men comics, this is one of 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.

Film

 * 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, (which claims that this entry should be under the Real Life 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 Colonel Quaritch at about 0:41 in this video
 * 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.

Television
""It's not revenge; it's prevenge. Getting to them before they get to you.""
 * Dollhouse - Used when Rossum's founder makes a last ditch effort to convince his pawns family that he needs to mind control the world.
 * 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.


 * 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.

Literature

 * 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.
 * Hilariously subverted in the HIVE Series. The big Council 'O Evil's policy is "Do unto others." Yeah, that's the entire motto.
 * Occurs in the Robert 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.

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.
 * 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.