This Trump speech sent a dangerous message to Iran—and the rest of the world.

Sometimes I wonder whether President Trump simply doesn’t think before he speaks or whether he has a weird compulsion to blow up the world.

It happened again Wednesday during his harangue at the Republican Midterm Convention, which was really a fancy name for a Trump campaign rally. Amid the usual rants of self-puffery and other fictions, he said this:

If [Iran] had a nuclear weapon, I’d be calling the Supreme Leader and I’d be saying, ‘Mr. Supreme Leader, how are you, sir? Is there anything we can do for you?’—as opposed to bombing the crap out of him.

Many in the audience laughed and applauded, when they should have gasped or moaned. Trump added, “We cannot let them have a nuclear weapon, it’s very simple”—as if that were the lesson of his little tale.

But the lesson that any world leader—friend, foe, or in between—would draw from this speech is simpler still: I need to get some nuclear weapons as quickly as possible.

Trump is telling the world’s leaders that he might bomb the crap out of them at any moment, or treat them like crap as a whim—but he would kiss the hems of their garments, bestow them with whatever favors they request, if they got themselves some nukes.

Maybe this is why he treats Russia’s Vladimir Putin, China’s Xi Jinping, and North Korea’s Kim Jong-un with such respect. Maybe it’s not just that he envies their absolute power on the home front or their unabashedly lavish palaces. Maybe it’s also because, like him, they have enough nuclear bombs to destroy much of life on earth—and he fears they might do so unless he showers them with praise and honor.

If this is part of his reasoning, he’s making two mistakes. First, he assumes that they’re as gullible as he is—that, since he believes the compliments they shovel his way, they’ll believe his shovelings too. This almost certainly is not the case; they are much more hardheaded and cynical in their views of the world and their interests.

Second, he apparently doesn’t consider what anyone outside the realm of his political base might think. He probably would treat Iran’s leaders differently—certainly he wouldn’t bombard their country with no good reason—if they had a pocketful of nukes to fire back at him. That’s what “nuclear deterrence” is all about; the possession of nuclear weapons deters others from behaving aggressively.

But a leader—especially the president of the United States—should know better than to say such things out loud. Doing so flashes a message in bright neon: You want to block me from bombing your country? You want me to be nice? Then go get yourself some nuclear weapons.

To the extent Iran still has the technology and the chops to build some A-bombs, you can bet that its scientists are revving up the centrifuges to further enrich their remaining stocks of uranium—while they still can.

Kim Jong-un long ago passed this hurdle—which, many have already concluded, is why Iran gets bombed while North Korea’s far more monstrous regime is tolerated, even spoken of respectfully. But to the extent Kim responds to other leaders’ signals, Trump’s comment may move him to accelerate the expansion of Pyongyang’s arsenal.

Meanwhile, many of our allies—notably South Korea, Japan, and a few countries in Europe—will no doubt absorb the same message. They have already been thinking about abandoning their restraint when it comes to going nuclear. They have the technical capacity to make the leap, they live in an increasingly dangerous world, they no longer trust the United States to come to their aid in a crisis. And now Trump is loudly confirming the correlation they’ve considered but would rather not think too hard about, until now—that a nuclear arsenal can win them safety and honor from even the most disreputable foes.

And when one country goes nuclear, the dominoes start to fall. If Iran builds nukes, Saudi Arabia would certainly follow suit. The royal family has said as much. If South Korea or Japan develops their own deterrent, China will accelerate their own deployments in order to overwhelm their deterrent. Regional arms races worldwide will ensue.

There is a school of thought—an extreme branch of “International Realism”—that views nuclear proliferation as a peace-building process: the more nations that have nuclear bombs, the less likely their adversaries will start war. Maybe. But maybe not, even stipulating their premise that all leaders (including savage and adventurous ones) act rationally. New and overly eager nuclear powers might not take the time and care to erect the guardrails that the larger powers gradually installed over the decades—the spy satellites that gauge the size of an opponent’s arsenal, the early-warning sensors that detect an incoming attack, the command-control machinery that ensures only those authorized to push the button have the ability to do so.

Even the superpowers’ guardrails—built and maintained at great expense during the Cold War—have failed at times, the radar mistaking flocks of geese for an ICBM attack or a computer mistaking a prerehearsed simulation for the real thing. At least the U.S. and Russia, oceans apart from each other, had half an hour to sort out the confusion before the missiles would land if they had been real. Countries much closer to each other might not have the time. In the real world, as opposed to in academic theory, a world bubbling over with nuclear weapons from many stovetops is more dangerous—not less.

Meanwhile, almost every time Trump talks, he sets off another problem, at times to the point of lighting a book of matches or pouring gasoline on a looming fire, often without seeing what he’s doing, without considering that words have consequences. We are learning, more and more, that this is what happens when someone of Trump’s character becomes president.