Steven Pinker explains how capitalism is killing war

"By Zack Beauchamp of Vox World. Excerpt:

"The idea that war is on the decline — that is, that there are fewer wars today and fewer people are dying from them than ever before — is hard for a lot of people to believe (including Republican presidential candidates).

And yet the data makes a very compelling case that that's true:

(Joe Posner/Vox)

Those numbers were put together by Steven Pinker, a Harvard psychologist whose book The Better Angels of Our Nature makes the strongest case yet that the world is getting progressively more peaceful. Pinker's argument has come under fire recently, with some arguing that it's way too soon for anyone to say we've turned the corner from an era of war.

I spoke with Pinker this week to discuss some of the reasons why, specifically, he thinks the world has gotten so much safer, especially in the past 70 years. We talked about the idea that war just isn't as profitable as it used to be, why Vladimir Putin and ISIS seem to think differently, and what world leaders should do if they actually want to make sure the unprecedented peace of the past 70 years holds. What follows is a transcript of our conversation, lightly edited for length and clarity.

Zack Beauchamp: One story you hear from political scientists for why there's been less war recently that it's just less profitable —countries don't gain very much, economically or politically, from taking over new land anymore. Does that seem right to you?

Steven Pinker: Yes, it's one of the causes. It's the theory of the capitalist peace: when it's cheaper to buy things than to steal them, people don't steal them. Also, if other people are more valuable to you alive than dead, you're less likely to kill them. You don't kill your customers or your lenders, so the arrival of the infrastructure of trade and commerce reduces some of the sheer exploitative incentives of conquest.

This is an idea that goes back to the Enlightenment. Adam Smith and Montesquieu extolled it; it was on the minds of the founders when they built incentives for free trade into the Constitution.

I don't think it's the entire story of the decline in war. But I do think it's part of the story. There was a well-known study from Bruce Russett and John Oneal showing statistically that countries that engage in more trade are less likely to get into militarized disputes, and countries that are more integrated into the world economy are less likely to get into trouble with their neighbors.

ZB: Is it just that pairs of countries are trading with each more, or has something fundamentally changed about the global economy?

SP: It's both. Countries that trade with each other are less likely to pick fights with each other. Independently, individual countries that get more integrated into the global economy are less likely to make trouble.

But one of the reasons I say this is only part of the answer is that in the Oneal and Russett analysis, it counted for some percentage of the variance in militarized dispute, but only a chunk. They found independent contributions from democracy and membership in the international community (namely, the number of international organizations and treaties that a country has signed on to).

Quite across from calculations of interest that are tilted by international markets and institutions, there's the idea of norms: what you consider and don't consider as a legitimate possible move. [Some scholars] argue that the main factor is that war has been delegitimated — at least among the great powers and the developed states — as a thinkable option.

In the 19th century, there was this cliché from [Carl] von Clausewitz that war was just the continuation of politics by other means: you consider whether to go to war [like any other policy option]. Now that's just not something decent leaders do.

Finally, cost-benefit calculations depend on what counts as a "cost." If you lose several tens or hundreds of thousands of your own citizens, is that a cost? And how big a cost is it? Now, increasingly, that counts as a cost: leaders are less likely to see their young men as cannon fodder, which means countries are willing to endure other costs to avoid that one. That's a result of the rise of humanistic sentiments, as opposed to nationalistic or ideological ones."