Washington Post
January 8, 2007
Pg. 2

Department Of Human Behavior

Wars Ultimately Measure Tolerance Of Pain

By Shankar Vedantam

Here's a question with three different answers. The first answer is derived from arithmetic. The second comes from common sense. The third is based on psychology.

Let's say you and I are generals of opposing armies. You have 10 divisions and I have four. If your troops are as good as mine, when would our hypothetical war end? The simplest answer is that the war will be over once four divisions of yours neutralize my four divisions; you have six divisions left, so you win.

The second answer, which is better than the first, is that the war should be over before it begins, because we both know what the outcome would be. If we agree on the outcome without fighting the war, neither of us would have to lose four divisions.

It's the third answer that has particular relevance to real life as the United States finds itself enmeshed in a struggle in Iraq that has already claimed the lives of more than 3,000 U.S. troops. Before we get to it, however, we need to unpack the implications of the second answer.

Given that the opposing sides in wars are often mismatched -- the United States and Saddam Hussein's Iraqi army, for example -- the question that bothers many political scientists is why wars occur at all. War imposes nonrefundable costs -- four divisions each in our hypothetical example -- on both the winner and the loser. If the weaker side is going to surrender anyway, doesn't it makes sense to cry uncle before the war starts? And shouldn't the stronger side be willing to accept a little less than total surrender if it can get most of what it wants without the loss of blood?

"The puzzle is if both sides knew what the outcome of the war would be, then both sides would be better off not fighting the war," said Dan Reiter, a political scientist at Emory University. A good analogy would be a conflict between labor and management at a company. Both sides pay a steep price in the event of a strike. If the outcome of the strike is predictable -- management raises salaries by 10 percent, say -- then both sides gain if they can agree on that goal, or even a more modest goal, without a strike.

What this model suggests is that wars are not primarily about conflicts between two sides, because most conflicts can be settled to the benefit of both sides without actual fighting. War, Reiter and others argue, primarily reflects a lack of information: When two sides cannot agree on how much damage they can inflict on one another -- and how much damage they can sustain -- war offers a mechanism to provide that information. (One implication of this idea is that you could help prevent or end wars by disseminating better information about how strong each side is, and how far each is willing to go.)

"If both sides think they are going to win, they will not be able to reach a bargain," Reiter said. "You fight wars to find out who is stronger and who is willing to take more punishment. When enough information has been provided, the war ends."

Let's apply Reiter's reasoning to the war in Iraq, which will then provide us with the third answer to our hypothetical question. Everyone knows that the U.S. military is the strongest player in the conflict. Nearly four years into a war that has morphed into a complicated struggle with insurgents, what information remains to be provided? The missing information is not about each side's ability to inflict damage, but the other component that Reiter described-- the ability of each side to withstand losses.

The third answer to when the hypothetical war will end is this: It depends. You have an advantage of six divisions, and if we were both willing to fight to the last man, you would win. But no one is ever really willing to fight to the very last man. What if you were really willing to lose only one division, while I was willing to lose three out of my four? Even though you outnumber me by more than two to one, I would win. In fact, I would win even if your troops were nearly three times as good as mine.

Knowledge about how much pain each side is willing to absorb is usually the most difficult information to obtain in war. Both sides always exaggerate their capacity for pain, because if your opponent knew you were willing to lose only one division, he would just hang on until you reached that breaking point. Successfully prosecuting a war, in other words, places what makes rational sense in conflict with what makes psychological sense: You need to deceive your opponent into believing you can tolerate huge losses. In fact, said John Mueller, a political scientist at Ohio State University, you probably have to deceive yourself about it, too.

During the Vietnam War, Mueller said, the United States assumed that beyond a certain point of losses, the North Vietnamese would break.

"Both sides in Vietnam talked about staying the course -- the issue is whether they were really ready to do it," Mueller said. As it turned out, the North Vietnamese were willing to accept casualties on a scale virtually unprecedented in the history of combat. Vietnam War-era Secretary of State Dean Rusk once calculated that North Vietnamese losses in the war, when measured as a proportion of population, were the equivalent of the United States losing about 10 million lives. American losses in Vietnam, by that same measure, were 175 times smaller -- but even that was too high.

"There was a breaking point," Mueller concluded. "It was the Americans who broke."