The war in Iran—so recently “ended” to the back-slapping acclaim of the administration that started it—is definitely back on. Iran attacked an air base in Jordan and other sites over the weekend, killing a total of three American soldiers (another service member was missing as of Sunday). The United States retaliated; Iran retaliated back. The New York Times described the countries as having “edged closer to a wider war.”

Donald Trump actually makes a fair point when he reminds people that Vietnam lasted a decade and cost 58,000 American lives (and two million Vietnamese ones, which he doesn’t mention as often). Iran isn’t close to being a “quagmire” just yet—not even a Dubya-style one. People can get a little overwrought when discussing these things.

Having said that, though, the future looks pretty grim. I mean, we’ve got Trump doing the one thing he said he’d never do: running a war. Knowing what we know about his attention span, his decision-making process, his willed ignorance of history, his refusal to read briefing papers, and his habit of responding to the last thing he saw on Fox News or Newsmax, we have plenty of reason to be worried here—and by “we,” I don’t mean liberals or Democrats or even Americans. I mean the world.

Let’s sort through the possible scenarios. Granted, they are extremely unlikely to involve 58,000 American deaths. But Vietnam was probably the largest military tragedy in the history of this country. There are other, less costly ways to lose a war. The United States lost around 4,400 service members in Iraq. That’s minuscule compared to Vietnam, but it’s still a war we largely lost (the military objective of toppling Saddam Hussein was achieved, but at a huge and off-the-books financial cost, and Iraq today is at best a kinda-sorta democracy).

So, some possible scenarios, from least bad to worst:

  • Trump bombs some civilian installations like power stations, commits a few war crimes but nothing that deeply shocks and appalls world opinion (bombing Pickaxe Mountain, for example); Iran finds a way to exert fuller control over the Strait of Hormuz; gas prices go up again, and Wall Street gets jittery; and Trump finds an exit ramp. In other words, we just rerun the conflict we’ve already watched transpire.
  • Or, Trump may decide to do a massive bombing raid on Kharg Island, the distribution point for 90 percent of Iran’s oil and natural gas. He bombed Kharg back in March, but that raid deliberately did not involve attacks on the island’s oil and gas infrastructure. Would Trump simply repeat that—an attack that had little discernible impact on events—or would he raise the stakes and hit the oil and gas installations this time? There has also been talk of a full-scale invasion of the island by U.S. troops. Doctor Testosterone over at the Pentagon probably can’t wait. Trump is surely holding off on both of these options because he knows full well that either would likely send gas prices soaring to the heavens and have other negative effects on the global economy. But Iran could do something that makes Trump change his mind, makes him feel he needs to do something dramatic, give Fox and Newsmax some A1 footage of things going boom.
  • An even worse scenario would see both sides escalating until some utterly predictable “unpredictable” thing happens. A U.S. bomb hits another school, or a town square, and a few hundred civilians die. Iran kills some critical mass of American soldiers—a couple hundred, say. Slowly, or maybe not so slowly, this becomes a real shooting war, the kind of conflict that leads the news every night and has no plausible end in sight.
  • Finally, there is the possibility that Trump gets impatient over a war he thought he was going to win in two weeks, and he takes drastic action that truly does shock world opinion. The wholesale bombing of civilian infrastructure. Bombing of civilian targets resulting in heavy casualties. The metaphorical “nuclear option” in this scenario would be quite literally nuclear. When people think of nuclear war, they think of the planet being blown to smithereens. But in fact, the United States has many small, tactical, variable-yield nuclear weapons in its arsenal, much smaller than the bomb dropped on Hiroshima (15 kilotons). I know—no one thinks this will happen, no one takes it remotely seriously. And they’re probably right. I’m just saying—with Donald Trump (and Pete Hegseth), never say never. I’m sure if you’d told the experts two years ago that the United States of America would start downing small watercraft in the Caribbean without apparent justification, going so far in at least one case as to strike a vessel a second time to kill the survivors, you’d have been greeted with condescending laughter.

I don’t think conscience would constrain Trump from dropping a message-sending little nuke on Qom. I mean, come on. I do however think there is one force that would constrain him: the stock market. That’s what he cares about at the end of the day. He has to know, all his ridiculous and offensive bluster aside, that he really screwed the pooch here. His war didn’t end in two weeks. Incredible as it must have seemed to him, the Iranian people did not rise up as one in gratitude to Trump and overthrow the mullahs. (Those who thought that was a possibility seemed to have missed the part where the ruling regime brutally put down—that is to say, slaughtered—the protest movement that for a time gained worldwide attention.) Now he has to find a way out of this without causing a global depression.

So that’s probably what he’ll do. Trump Always Chickens Out. He has more important things on his mind, at least more important to him: money to steal, lucre to rake in while still in office, a ballroom to build, a Reflecting Pool to fix (after re-ruining it), an election to rig, tens of thousands of brown people to harass and detain and, when deemed necessary, kill.

But as this war restarts, we would do well to remember two things. First, war is always unpredictable; things happen that the experts said would never happen, and before you know it, the casualties are mounting, and the warmakers are screaming about patriotism. Second, Trump is Trump—a vain man-child who rarely thinks more than an hour or so ahead. At any given moment, he’ll do what he thinks he needs to do to get out of whatever immediate jam he’s put himself in. That’s why we’re in this war in the first place. And that’s why Donald Trump running a real-live war is the world’s worst nightmare.