President Donald Trump’s now-notorious Tuesday tweet about his “Nuclear Button” - the capital letters are his - has prompted, as one might expect, a lot of tortured analysis, frenzied speculation and existential despair:

“North Korean Leader Kim Jong Un just stated that the “Nuclear Button is on his desk at all times.” Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!”

Just to avoid any misunderstandings up front: Yes, it was stupid. Yes, we shouldn’t talk about nukes this way. And yes, the size of the button doesn’t matter.

Yet for all its frantic cogitation on the matter, the American media still seems to be leaving out one gigantic facet of the story: What about the South Koreans?

At the risk of offending some of my friends in Korea, theirs is a country that we Americans tend to forget too often. Few of us seem to grasp that South Korea is a thriving democracy and an industrial powerhouse of 50 million people that has been one of our closest allies for the past seven decades. Thirty-six thousand U.S. troops died helping the United Nations defend the South from northern aggression in 1950-1953. None of which, of course, prevents us from indulging in our habitual obliviousness toward yet another faraway country.

Still, Trump’s casual blustering with nukes stands out even by our dismal geographical standards. His tweet - which of course dramatically simplifies the actual command procedure required to launch nukes anywhere in the world - also blithely bumbles over the political or strategic realities of the Korean Peninsula, factors a competent leader would probably want to consider before unleashing a devastating war in Northeast Asia.

The simple fact of the matter - and it can’t be repeated enough - is that North Korea is still a long way from being able to wage war against the continental United States. If war begins, it’s not heartland Americans who will pay the price. It’s South Koreans.

Unless you’ve been to the military line of demarcation that divides North and South Korea - and which Trump managed to miss on his recent trip to the peninsula - you might find it hard to imagine how entangled the two countries’ fates remain today. Greater Seoul, a megalopolis of 25 million people, is just 35 minutes away from the border with the North - one reason that a Pentagon war game reportedly determined that the onset of war would kill 20,000 people in the South each day it continued.

North Korea has an estimated 11,000 artillery tubes and rocket launchers set up in subterranean sites just north of the border, and all Kim Jong Un would have to do to inflict horrific damage is lob the maximum number of munitions over that line into the densely inhabited South. If he wanted to run up the death toll, of course, he would merely have to resort to his large stores of chemical and biological weapons - not to mention his nukes, which would be far easier to deploy against the South than anyone else.

As the veteran Korea correspondent Barbara Demick notes:

“The oft-cited statistics about North Korea’s military are formidable: 1.2 million soldiers in the fourth-largest ground army in the world, among them more than 100,000 special forces trained to infiltrate South Korea. Although its military hardware dates back to the Soviet era, North Korea has more tanks than the United States (3,500 compared with 2,381) and more artillery pieces than China. Its nuclear fissile material is enough for least 12 nuclear weapons, possibly as many as 60, depending on their size. (According to the Arms Control Assn., the U.S. has 1,411 strategic nuclear warheads.)”

Even if the North significantly ups its game technologically, all this still means that the Korean Peninsula will remain the main battleground in any war. And while it’s true that our current security arrangements with the government in Seoul dictate that the United States assume operational command over all forces in the theater, that shouldn’t give us an unlimited right to ignore the South’s wishes about how such a conflict should proceed. It’s the South, after all, that would bear the brunt of any war. Trump’s blustering unilateralism ignores this.

Small wonder, given Trump’s outbursts, that many South Koreans already see him as a bigger threat than Kim Jong Un. Perhaps these fears are exaggerated. But guess what. Scaring the hell out of your most important ally is a really bad way to prepare for war with a nuclear-armed North Korea. By playing these games, Trump is eroding Seoul’s trust in our reliability, which could prompt it to reassess its options - by starting, for example, to develop its own nuclear deterrent, thereby triggering a new arms race in one of the world’s most strategically sensitive regions. I, for one, would find it hard to blame South Korea.

South Korean leaders may well come to the point where they decide that they’re willing to pay the price to eliminate the threat of their volatile neighbor to the north. But they should be able to do that on their own, without our imposing such a decision on them. It’s their country, after all.