A few days ago, Kim Jong-un addressed North Korea on his state-sponsored TV station with a new boast: The country had finished amassing its nuclear arsenal, and he even has a shiny new “nuclear button” on his desk, ready to go.

This provoked an entirely predictable response from Tweet-button-happy US president Donald Trump: “I too have a Nuclear Button, but it is a much bigger & more powerful one than his!”

The big red button as a symbol of willy-nilly destruction—and the irresistible yet irrational allure we feel to push the damn thing—is not new. In fact, the trope predates the nuclear era entirely.

But does the absurd imagery and puerile one-upmanship make the situation any less dangerous? This foreign policy crisis is being shaped by the particular psychology of the digital age: We are all button-pushing addicts now.

The psychology of a button

“We willingly push any and every button because we hope that it provides a squirt of dopamine for pleasure,” psychologist and California State University professor Larry Rosen tells Gizmodo in a definitive dive into the big red button. “Or at least, [it] reduces the cortisol that is making us anxious—until we see what pressing it means.”

You’ve probably read something about the reasons social media, video games, and even email are so addictive: we’re conditioned to seek rewards. Getting one activates pathways in our brain that make us crave another, and another. Our phones and computers are full of buttons. They are the mechanism by which we receive our little rewards.

A nuclear button, even a proverbial one, is different, obviously. But as pop culture tropes can tell you, that doesn’t mean we don’t feel compelled to push them. “In psychology, this can be explained by reactance theory, which says that if our freedom of choice is threatened, we feel compelled to protect that freedom, making us want the taboo thing even more,” Gizmodo’s Bryan Lufkin writes.

Fortunately, a big red button that can launch a nuclear attack has never actually existed; it’s a metaphor for how (relatively) easy it could be, and how removed the act could feel from its consequences.

In the 1960s, Harvard Law School professor Roger Fisher proposed an idea to friends in the Pentagon, which he later wrote about in a fascinating piece published in Bulletin of the Atomic Sciences. Instead of keeping nuclear codes in a suitcase, you’d implant them in the heart of a volunteer, who’d carry with him a “big, heavy butcher knife,” Fisher wrote.

“If ever the President wanted to fire nuclear weapons, the only way he could do so would be for him first, with his own hands, to kill one human being. The President says, “‘George, I’m sorry but tens of millions must die.’ He has to look at someone and realize what death is—what an innocent death is. Blood on the White House carpet. It’s reality brought home.”

The Pentagon thought this was a terrible idea: “Having to kill someone would distort the President’s judgment,” Fisher’s contacts replied. “He might never push the button.”

Where did the big red button come from?

Where big red buttons do exist—and for good reason—is on technologies that might need to be shut down to avert a disaster (not create one): nuclear reactors have them; so to, for that matter, do treadmills.

Nuclear reactors have a failsafe red button known as a “SCRAM” switch, which inserts control rods into the core to halt a runaway nuclear reaction. The acronym stands for “safety control rod axe man,” which was supposedly coined by Enrico Fermi when the world’s first nuclear reactor was built at the University of Chicago’s Stagg Field. We wrote about that in a Quartz Obsession. (Yes, there was literally a guy with an axe standing by.)

Alphabet’s DeepMind unit, which has developed AIs capable of learning on their own and beating humans at board games, is also nervous about creating adverse consequences. In a recent research paper, it warned that “reinforcement learning agents interacting with a complex environment like the real world are unlikely to behave optimally all the time,” and said it “may be necessary for a human operator to press the big red button to prevent the agent from continuing a harmful sequence of actions.”

Culturally, the idea of the irresistible, apocalyptic button has been around even longer. In 1896, a Parisian newspaper published a satirical account of Thomas Edison destroying London by pressing “button No. 4.” By the 1910s, big dystopian buttons had begun to appear in the work of sci fi authors like H.G. Wells, and in 1932 the Weekly Irish Times writes that atomic energy will lead to “a time when, by the pressing of a button or turning of a switch, it will be possible for somebody to explode the whole world like a penny balloon.”

US president Lyndon Johnson evoked the image in 1964, saying that a leader must “do anything that is honorable to avoid pulling that trigger, mashing that button that will blow up the world.” Just four years later, US president Richard Nixon claimed he wanted North Vietnam to believe that he “has his hand on the nuclear button.”

The truth about that big red button

We can be reasonably confident that whatever nuclear capacities North Korea has, they aren’t accessible by a single button, however big or red it might be. Experts say that North Korea’s long-range liquid powered missiles—the ones that could potentially reach the United States—cannot be fired at a moment’s notice. Previous tests have required several hours to fuel up the ICBMs, though short-range missiles using solid fuel could be prepared more quickly.

The process in the US is a bit more complicated, too. As far as the president’s role is concerned, launching an attack requires the “nuclear football,” a 45-pound briefcase carried by a military aide which accompanies the president wherever he goes. Inside is “a list of attack target countries and target types the President can carry out, all listed out on a menu that looks a lot like a cartoon.”

To authorize a strike, the president has to provide a code that he carries with him on a laminated card nicknamed “the biscuit.” He does not need approval from anyone else. The war room would then encodes a war plan with the codes needed to unlock the missiles into a message about the length of a tweet, that’s broadcast to launch crews. After the order is received, it would take about five minutes to launch land missiles and 15 to launch missiles from a submarine.

This post was adapted from a Quartz Obsession email. Sign up here.