The Indicator from Planet Money - What Iran teaches us about why wars start

Episode Date: June 30, 2026

If war is so costly, why do we keep fighting them? We dig into the wars in Iran, Ukraine and Gaza to understand the incentives that lead countries into violence. Today on the show, the five factors that lead to war. Chris Blattman’s book is Why We Fight: The Roots of War and the Paths to Peace.Fact checking by Sierra Juarez. Your Next Listen — The new economic arms race Connect with The Indicator — Sign up for The Indicator’s brand new newsletter — Buy the Planet Money book — Find our socials, YouTube and more! — For sponsor-free episodes, subscribe to NPR+ See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

NPR. Yesterday, President Trump claimed that the U.S. and Iran are going to talk in Doha, as officials try to patch up a ceasefire agreement that was broken by strikes over the last week. So in this liminal moment, we thought it would be a good time to look back and ask, how did we get into this? Chris Blackman is an economist and political scientist at the University of Chicago, who studies the roots of war and conflict. Once you start thinking about conflict and violence, you can't stop thinking about

anything else. Chris's obsession with war and the data on conflicts revealed something to him. He says the several weeks of intense fighting between the U.S. and Israel on one side and Iran on the other is actually kind of typical. I think the average war in the last 200 years has been less than two months long and so this fits that pattern. We don't know what will happen next, but if the fighting stays at the current lower simmer, then the Iran war's hot stage matched average historical lengths. The two world wars do not fit that pattern. Neither does the war in Ukraine or Gaza. This is the indicator from Planet Money. I'm Waylon Wong. And I'm Darien Woods. Today on the show, why we fight. We speak to an economist about the incentives that push countries to war.

We ask, if violence is so costly, why do some wars keep stretching on and on? Chris Blytheon got into studying war by accident when he was studying industrialization. in East Africa. And then I met a humanitarian worker who was working in a war in northern Uganda. And so I followed her there. Wait, so you followed somebody into a war zone? Well, I will say that led to a dissertation together that led to several papers together. We're about to celebrate our 20th wedding anniversary.

And we have a 13-year-old boy and a 15-year-old girl. So it was a pretty successful strategy. Chris and his wife, Jeannie Anon, have now published paper. about reintegrating child soldiers and how cash and training can help women in war-affected areas. And what Chris's research reveals is something that a lot of us intuitively know. War is actually, there are no winners, right? There's always a better solution. There are circumstances where victory and some amount of luck makes you better off after the fact. Most of the time, that's not true.

According to Moody's, this year's war with Iran has cost the U.S. at least 132, billion dollars. That's about $490 for every adult in America. That's counting the military spending plus broader economic fallout like the spikes in gasoline prices. It's also resulted in the deaths of 13 U.S. service members, more than 3,400 Iranians, and dozens elsewhere in the Middle East. So if war is usually economically bad for both parties, the big question is why do countries fight? I mean, it's important to remember most of the time they don't. So North and South Korea have been in a formal state of war for decades. And there is intermittent small bouts of violence, which I would call skirmishes.

But generally, they have not fought at any scale. Iran and the United States have essentially been in a state of war for decades as well. And again, this erupts into short-lived, sometimes hours or days-long skirmishes, or as we've seen in recent times, you know, five to six weeks. of violence, but that's five to six weeks of violence out of 45, 50 years of hostilities. And so not to diminish what's going on, but war is really the exception because they're just so horrendously costly. Chris is reluctant to make too many statements on the war in Iran.

You know, we're still in the middle of it. Who knows what's going to happen? But the broader point he's making is that groups disliking each other is typical. Groups loathing each other is typical too. But all-out conflict that lasts longer than a brief flare-up is rare. So that raises a question. What went wrong in wars like Ukraine and Gaza? Russia's full-scale invasion of Ukraine took place over four years ago, and heavy fighting continues.

Israel and Hamas were in a hot war for two years and are now, on paper at least, in an uneasy ceasefire. If we start from the idea that wars are horrendously costly, then there has to be something that gives one side of the other an incentive, however, temporary, to decide to turn to violence. Chris says the first reason is when leaders don't have the incentives to work in the best interests of their country, take Russia's invasion of Ukraine. Putin wasn't paying the costs of this war directly. This is true of many leaders, even democratic ones, but it's especially true of autocrats. Democracies like the U.S. aren't immune. President Trump's sons, for example, own part of a drone manufacturing company. They might profit from war even if it's costly for the country.

The second explanation Chris has for violence is something a little more psychological. Values and ideals. Things that only war can deliver. The extermination of an ideology or an ethnic group that you loathe, the idea you hold for your ethnic group or your nationalist ideal or the place you want in history. And vengeance is another very powerful example. They're not irrational. They're just enduring preferences. And for lack of a better label, I think of these as sort of intangible incentives. These incentives are intangible because if you're motivated by, say, a belief that a war will secure your place in the afterlife, that's not a material reward. Reason number three, Chris says, is uncertainty. Amidst this uncertainty, how strong is Iran, how strong is

Ukraine, how powerful are my forces, how likely is a decapitation event, likely to create regime change? All of these things just have tremendous uncertainty. Chris says you can think of countries as playing a game of poker. Sometimes they're bluffing and pretending to be stronger than they are. Sometimes they're not. But it can be really hard to tell the difference. And when countries misjudge others, that's when long wars can start. The Trump administration said the war in Iran would be just a, quote, short excursion that's proven not to be the case. To see the United States bomb Iran after years of trying everything else is perhaps not that surprising. In these extremely long Cold Wars with lots and lots of uncertainty, I think we're eventually going to see conflict.

Chris's fourth reason for violence is commitment problems. The classic commitment problem is this idea of a rising power facing a weakening one. If you're a weakening power and you look forward to the day when that rising power is going to dominate you, you have a choice. Am I going to take you out now and prevent your rise and maintain my dominance? Or do I wait until the day when you might dominate me? And some scholars have called that the most important cause of war in human history. And they'll point to the Peloponnesian War in ancient Greece or the World Wars. Yeah, the Thucydides trap is the famous example.

The Thucydides trap. The Thucydides trap recalls how ancient Sparta felt threatened by the rise of Athens, which led to the Peloponnesian War. Now it refers to the risks of conflict anytime a growing country starts to rival an existing power. And the reason we should care about this is because every single time Xi Jinping talks to foreign journalists or, for that matter, a U.S. president, he brings up the Thucydides trap, right? Now, the one thing we've learned is it's not. There's nothing inevitable about it. And I think the best bets are not for there to be a war between the United States and China. But it's

fundamentally scary and dangerous if Xi Jinping thinks that, you know, war is inevitable between rising powers. Chris's fifth and final reason for why we fight is misperceptions. Again, Chris brings up the Russian invasion of Ukraine. Most people say that Putin was overconfident. They say that he was overconfident either because of his psychological bias or because he was getting bad information, basically because people weren't pushing the real truth up the chain. Yeah, in reality, Ukraine was no way near as much of a pushover as Putin might have been

led to believe. It's all a bit gloomy. But Chris's somewhat optimistic take, though, is that usually the high-grimed, costs of war reduces the chance of all-out violence. Chris says we often think about drawn-out conflicts like the Iraq War. But what about all the very short fights? In 2003, the U.S. deployed to Liberia and helped end a year's long civil war in a matter of days.

This episode was produced by Cooper Katz McKim and Angel Carreras with engineering by Travis Hagen, who's fact-checked by Sierra Juarez. Kakin Cannon edits the show and The Indicator is a production of NPR. There is so much news that we're following. Yeah, but we only have five shows a week. Only five. So we should do 20 shows a week, I guess? Is that what you want, Waylon? Yeah, give me a red bulb. Get right on it. Yeah, well, we want to bring you more news and analysis each week. And that is why we have officially launched a newsletter.

That's right. Every Friday, we will bring you the news we couldn't get to, answer your listener questions, put out callouts, and tell you what we're doing outside of work. Mostly paragliding. Well, Adrian, extreme sports. Sign up now at NPR.org slash indicator newsletter.