If not for Soviet military officer Stanislav Petrov, the world as we know it could have ended on Sept. 26, 1983. That day, sitting in a bunker south of Moscow, the 44-year-old Petrov received an alert that five U.S. nuclear missiles were in the air headed toward Russia. Petrov correctly assumed it was a false alarm and decided not to report it to his superiors, thus preventing a counterattack and nuclear Armageddon.

Reports surfaced this week that Petrov died earlier this year, offering an auspicious reminder that mankind is still just one blunder away from wiping itself off the face of the planet with nuclear weapons. After Donald Trump’s speech Tuesday at the U.N., in which he threatened to “totally destroy North Korea,” that message bears repeating once again.

From his promise to respond to missile launches with “fire and fury,” to his blustery tweets about being “locked and loaded,” Trump’s rhetoric on North Korea has been consistently dangerous, but his menacing address to the world’s leaders on Tuesday was Trump at his most reckless.

“Rocket Man is on a suicide mission for himself and for his regime,” Trump said in his first speech to the U.N. General Assembly, apparently using the Elton John song title in reference to Kim Jong Un. “The United States is ready, willing, and able, but hopefully this will not be necessary.”

“Rocket Man is on a suicide mission for himself and for his regime”

Most experts agree that the message — which combined an insult with a threat of total annihilation — will only provoke North Korea to launch more missiles. Trump “handed the Kim regime the soundbite of the century,” Marcus Noland, a researcher at Peterson Institute for International Economics, wrote. And as North Korea pushes the narrative that it needs nukes to deter a U.S. attack, Trump did his part to confirm that belief on a global stage.

Trump has often said that he wants China to exert more pressure on North Korea, but the Chinese were not pleased with his speech either. The People’s Daily newspaper ran an op-ed Wednesday that called his remarks “unhelpful,” and said his rhetoric will only push North Korea “to pursue even riskier policies, because the survival of the regime is at stake.”

Perhaps most troubling was Trump’s comment that Kim is “on a suicide mission.” The drums have been steadily beating within the Trump administration for a “preventative war” with North Korea, and if Trump truly believes that Kim doesn’t care about self-preservation and would strike first in a nuclear war, it’s not a stretch to think he could be persuaded to support a preemptive attack against Pyongyang.

Of course, there is no such thing as a “preventive war” with North Korea. That term, coined by Trump’s National Security Adviser H.R. McMaster, is a fallacy. In addition to nuclear and chemical weapons, North Korea has the world’s fourth-largest standing army and a huge arsenal of heavy artillery that would be used to lay waste to South Korea in retaliation for any military attack. Trump’s ex-adviser Steve Bannon acknowledged as much shortly before his departure from the White House.

“There’s no military solution [to North Korea’s nuclear threats]. Forget it,” Bannon said at the time. “Until somebody solves the part of the equation that shows me that 10 million people in Seoul don’t die in the first 30 minutes from conventional weapons, I don’t know what you’re talking about. There’s no military solution here; they got us.”

Kim Jong Un isn’t crazy. He wants to remain alive and stay in power. North Korea’s constant missile launches may seem unhinged, but the endgame is to convince the U.S. that any attack on the regime would be swiftly met with nuclear retribution. The big risk now is that Trump gets fed up with the antics or feels emasculated, prompting some sort of rash response that spirals into all-out war.

As president, Trump has the sole, unchecked authority to launch America’s nuclear weapons, though legislators are hoping to change that. Democratic Sen. Ed Markey of Massachusetts has already introduced legislation that would explicitly ban the first use of nuclear weapons without a declaration of war from Congress, and after Trump’s U.N. speech, Republican Sen. Bob Corker of Tennessee suggested that perhaps it’s time to revisit whether the president should be able to unilaterally start a nuclear conflict.

Nuclear weapons experts were equally alarmed by Trump’s comments. One of the more poignant responses came from Melissa Hanham, a researcher at the Middlebury Institute of International Studies at Monterey. In a series of tweets, Hanham warned that the world is nearly two generations removed from World War II — meaning most people today are only vaguely familiar with the horror that was inflicted on Nagasaki and Hiroshima.

“These weapons can kill more people in a few seconds than any other weapon we have conceived of”

“These weapons can kill more people in a few seconds than any other weapon we have conceived of,” Hanham said, adding that nukes “poison land, air, and water” and could easily “end the human species.”

Last year, Trump said he would be “the last person to press that button” and launch a nuke, but he’s also repeatedly expressed a willingness to do so if he feels it’s necessary. In this context, recent reports that Trump is considering the deployment of so-called “mini-nukes” to the Korean Peninsula are troubling, since he could feel emboldened to order a launch on the belief that the fallout would be less devastating than a huge H-bomb.