Here on the Better Samaritan we’re learning how to “do good better.” Using Jesus’ story as a guiding metaphor, this involves getting better at (like the Good Samaritan did) helping the person left by the side of the Jericho road who was robbed and beaten up. It also involves learning how to make the metaphorical road safer. Why We Fight: The Roots of War and the Paths to Peace, by Chris Blattman, helped me to better understand why the road is dangerous at times–and also how we can make it safer. Full disclosure: the author, who is professor of global conflict studies at The University of Chicago, is also my brother-in-law. I highly value Chris, not just for marrying my sister, but also for important insights from his research and experience. Whether you work at a national or neighborhood level, I think you’ll find this conversation and his book encouraging and helpful in your work for peace.

Kent: In the past year, Afghanistan and then Ukraine have dominated international headlines. Yet in “Why We Fight,” you explain that war is rare because the cost to everyone involved is so high. With the depressing human cost of war in the news everyday, I found your book, and this insight, encouraging. Can you explain how you came to understand that war is rare when it can “feel” like it’s happening all the time?

Chris: Well, I have to point out that I didn’t write a book called “Why We Don’t Fight.” Obviously we do. But I wanted people to start with the realization that we have really strong reasons not to fight, and so we usually don’t.

You’re right that this seems like a strange message for this moment when, as we’re talking, there’s a massive conflict in Ukraine. But I’d argue that’s because we only pay attention to the conflicts that happen.

One example came two weeks into Russia’s invasion of Ukraine, when India accidentally launched a cruise missile at Pakistan. Calm ensued. War would’ve been so unimaginably costly, both sides strove to avoid it. As they have for decades.

Another example is that schoolchildren will learn about the US invasion of Afghanistan for the next two generations. But almost none of them will hear about America’s 1994 invasion of Haiti. After a military general seized power from a newly elected President, Colin Powell arrived in Haiti, with the backing of the United Nations. Powell showed the new dictator a video of dozens of American military planes taking off full of soldiers and equipment. That’s not a live feed, Powell explained, that was two hours ago. The general capitulated right there. Fighting wasn’t worth it. It almost never is.

Even Putin tried to avoid war in his own insidious way. For 20 years he tried every underhanded means possible to co-opt Ukraine. Dark money, propaganda, political stooges, assassinations, support for separatists. He tried everything else he could because as violent and costly as these things were, not one of them was as risky or as ruinous as war.

The problem is that nobody writes books about the times we don’t fight. We overlook all the quiet compromises.

That makes us like doctors who only see critically ill patients, and don't know about the normal state of human health. That has a few bad effects. One is that it could make you demoralized and depressed. Why work so hard to make all these ill people healthy if you don’t realize how common it is. More seriously, those doctors are probably going to misdiagnose the ailment, and dole out terrible treatments.

I don’t want us to make that mistake with war.

Kent: You give five reasons for war. Unfair question since you go into depth about each in the book, but I’ll ask anyway: Can you briefly explain each?

Chris: Everything starts from the fact that war is unimaginably destructive. We can see that playing out in Ukraine right now: the deaths; the fields untilled; the cities that look like rubble; the empty treasuries on both sides.

Terrible costs like these push most groups to try everything possible to avoid all-out fighting. I like to tell people: if you take just one insight from the book, I suggest this: war is costly, and every answer to why we fight is a reason that a society or a leader ignored those costs.

Now, this can happen in lots of ways, but like you say, a big message in the book is that there are really five ways this happens. Most explanations for most wars fall into one of these five reasons that societies or leaders ignore the costs or are willing to pay them.

Let me stick with the example of Russia and Ukraine.

The first I call unchecked interests. Think of Vladimir Putin. He can ignore most of the costs, because he’s not accountable to the people who pay them. Autocrats like him are insulated from all that. They can pursue their private interests. These unchecked leaders only care about the fraction of the costs they face. So they’re too quick to use violence.

The second I call intangible or ideological incentives. An example is Putin’s imperial obsessions—a desire to make Russia great again, or to achieve personal glory and a place in history. War is still costly and risky to him (even if he’s a dictator), but he’s willing to pay that price for intangible and ideological reasons.

The third I call uncertainty. We all have to remember how uncertain all these were just a few months ago: the bravery and resolve of ordinary Ukrainians; Russia’s military strength; the West’s unity on sanctions. When circumstances are this uncertain, it’s easy to get the costs and benefits wrong. Nobody expected Russia to get a bad draw on all these things—least of all Putin. War is partly a gamble.

The fourth I call misperceptions. Because it’s not just that we’re uncertain, we also take in information in biased ways. Every story you hear about Putin being insulated, isolated, overconfident, or underestimating the costs of war—these are stories of misperceptions. Basically, it means judging the costs and risks wrongly.

The fifth and final is a strategic concept known as a commitment problem. This happens when one side can’t trust the other to commit to a peace agreement, so it has to lock in its advantage while it can.

This one isn’t as applicable to the Russian invasion as the other four, but let me lay out how it could play a role. Earlier this year, Ukraine had acquired Turkish drones, and was building its own defensive missiles, like the Neptune ones that sank the Russian warship. Invasion was only going to get more difficult for Russia, and the Ukrainians could hardly commit not to protect themselves. Meanwhile, the Ukrainians were getting closer to the West and democracy–again, something they could hardly commit not to do.

Arguably, Russia was at its peak leverage. It was now or never. Amidst this commitment problem, it was time to take advantage of this fact and invade before their ability to do so disappeared.

Those are the five. Of course, one thing I want to be clear about is that explaining aggression isn’t excusing it. Just because Purin had strategic or ideological incentives to invade doesn’t make it right.

Kent: You don’t just write about nations going to war. You also explain your experience with other conflicts, for example with gangs in Chicago. Can you talk about that?

Chris: So my day job doing research is trying to find and test ways to create peace in civil wars and violent cities. And I think the reasons why nations fight—and what stops them—can help us understand war and peace at these lower levels. And vice versa.

Let’s take Chicago where, like a lot of American cities, homicides have been spiking. Why are young gang members shooting one another?

I see evidence of at least three of the five reasons. One is intangible incentives. Not glory, like the story of Putin. More often it’s vengeance. They’re pursuing blood feuds. Someone killed their brother or their best friend. They’re willing to pay the costs of fighting for their honor or because they’re angry and they want revenge.

A second is misperceptions. Some men are making these decisions in a hot, reactive state. So their passions get the better of them.

But then there’s uncertainty—which is subtler but arguably more important.

One of the gang leaders I worked with told me about the first time he was robbed as he was selling drugs. They thought he was weak. He told me he realized: If I don’t do something about this, I’m done. So he tracked down and shot the man who robbed him. He had to do that a few more times to build a reputation. By the time I met him in a gang exit program I helped design, he was a repeated but regretful killer.

So why did he need to construct a reputation? Because of uncertainty. There’s no need for a reputation in a world where everyone knows your strength. But in an uncertain world, sometimes fighting is your best way to signal to others you should not be messed with—a strategic incentive to start some fights that then prevents others.

I think this is one of the reasons the US stayed so long in Afghanistan. America wasn’t just pursuing revenge. It was building a reputation, to warn every other rogue state or terror group what would happen if they attacked American soil. So obviously these fights (Ukraine, Afghanistan, gangs in Chicago) are incredibly different, but they can share certain psychological and strategic logics.

Kent: I think this book is helpful for NGOs, missionaries, and churches who are working on justice issues in their communities. For a humanitarian practitioner, how can understanding root causes of war (and of avoiding war) help us be better “peace builders” for the communities we work in?

Chris: This is something I struggled with my whole career. It’s how I tried to end the book. I didn’t want to end with a tale of “it’s all getting better.” And I didn’t think there was a 10-point policy prescription that everyone could follow.

I think of it a little like being a doctor. Someone comes to you with an ailment. You don’t just give them tylenol and radiation and send them on their way. You carefully diagnose what’s going on, knowing that you might get it wrong. You try a treatment, then look carefully to see if it has the expected effect. If not, maybe the diagnosis was wrong, and you try again.

Then there are also people designing new treatments and medicines. They’re trying to understand the deep roots. Then they develop something new—maybe something just a tiny bit different—and they test it out cautiously and look for signs of ill effects, or unintended consequences. That’s how medical progress has been made. In these little steps, by thousands of doctors and nurses and lab technicians.

Peacebuilding doesn’t happen in huge leaps with grand solutions.

Peacebuilding to me is the same. It doesn’t happen in huge leaps with grand solutions, and there’s no best practice that every possible conflict needs (like tylenol and radiation). In the book I try to give people a better toolkit for diagnosis—the focus on the costs of war, the attention to the healthy cases, and the five reasons. I hope people are better able to see what’s going on in their city or community or country.

I also walk through the toolkit the world has for building peace, and how each of them attacks at least one of the five reasons. But if you’re working in local communities you’ll be like a doctor—testing the treatments, never being too confident you have the diagnosis right, always on the lookout for unexpected effects, and always trying to improve the diagnosis and the medicine.

Kent: I heard progress reports along the way as you wrote this book over several years. As you look back, what encourages you most about what you learned and what discourages you when considering the paths to peace that are ahead?

Chris: One thing I learned—and what I think a lot of the world is waking up to—is that the peacebuilding tools we have are not all that effective when a great power has an unchecked leader, an ideological incentive, and is misperceiving or uncertain or unable to commit. So the United States could invade Iraq, or Russia could invade Ukraine, and we don’t as a global community have enough tools to help these disputes get resolved without violence.

A lot of Americans are skeptical about tying their county’s hands by signing on to international agreements, like the international criminal court, or widening who gets a say on the United Nations Security Council. And I get that. It puts American leaders at risk. And there are a lot of nasty regimes out there that would use these international institutions to do things that aren’t in our interests. But current events have reminded me that the nasty regimes are capable of doing some really terrible things because they aren’t bound by international law. I think we have more to gain than lose by strengthening these institutions, deeply flawed as they may be.

The other more optimistic thing I learned, however, is that when it comes to every other kind of conflict—small nations fighting each other, civil wars, gang wars, street violence— collectively we know a lot more than most people think. More than even I thought, even after working in the area for 20 years. That’s great. What was frustrating is that no one ever tried to bring it together in one place, all the lessons from different social sciences, and all the insights from the people out there who are actually doing the hard work. So that’s what I tried to do, and hope people find it helpful and inspiring.

Christopher Blattman is a Professor at the University of Chicago’s Harris School of Public Policy. You can follow his work at and on Twitter @cblatts.