Why War Is Never Really Rational

"The art of war," Adam Smith wrote in The Wealth of Nations, "is certainly the noblest of all arts." In every culture, war is considered society's most noble endeavor (recent threat of nuclear war and mass annihilation has made a slight dent in this universal passion), although what is considered good and noble in one society may well be considered evil and bad in others. War is usually much better than peace at defining who is the group, what are its boundaries, and what it stands for. War is also more compelling and effective in generating solidarity with something larger and more lasting than ourselves. War compresses history and dramatically changes its course. There is urgency, excitement, ecstasy, and altruistic exaltation in war, a mystic feeling of solidarity with something greater than oneself: a tribe, a nation, a movement, Humanity. That's also why cable news so loves it.

War is what most clearly defines who we are, for better or worse. And it has always been that way.

The key justification that President Obama evoked in going to war in Libya, and anywhere else around the globe where America's survival and safety are not directly threatened, is that failure to act "would have been a betrayal of who we are." The message, to remind ourselves and the world, is that America protects people who are menaced with annihilation for wanting freedom.

Obama's erstwhile presidential rival, Senator John McCain, countered that while this moral imperative may be laudable, "the reason why we wage wars is to achieve the results of the policy that we state." And that policy, as the president himself proclaimed, is that "Gaddafi must go."

Politicians and pundits across the ideological spectrum intone that the military mission remains murky, even contradictory, because as Adm. Mike Mullen, Chairman of the Joint Chiefs of Staff, put it: "the goals of this [military] campaign aren't... about seeing [Gaddafi] go. It's about eliminating his ability to kill his own people." So what is the sense of fighting to prevent Gaddafi from massacring his people if, as Adm. Mullen conceded, "certainly, potentially, one outcome" is that the dictator remain in power, potentially to kill again?

Yet the inconsistency between war as a moral imperative versus political policy runs way wider and deeper than the Libya conflict. It goes to the heart of human nature and the character of society. For despite the popular delusion that war is, or ought to be, primarily a matter of political strategy and pragmatic execution, it almost never is. Squaring the circle of war and politics, morality and material interests, is not just Obama's or America's quandary, it is a species-wide dilemma that results from wanting to believe with Aristotle that we humans are fundamentally rational beings, when in fact recent advances in psychology and neuroscience strongly indicate that Enlightenment philosopher David Hume was right to say that "Reason is, and ought only to be, the slave of the passions."

Models of rational behavior predict many of society's patterns, such as favored strategies for maximizing profit or likelihood for criminal behavior in terms of "opportunity costs." But seemingly irrational behaviors like war -- in which the measurable costs often far outweigh the measurable benefits -- have stumped thinkers for centuries. The prospect of crippling economic burdens and huge numbers of deaths doesn't necessarily sway people from their positions on whether going to war is the right or wrong choice. One possible explanation is that people are not weighing the pros and cons for advancing material interests at all, but rather using a moral logic of "sacred values" -- convictions that trump all other considerations -- that cannot be quantified.

As Darwin noted in The Descent of Man, and Sun Tzu millennia before in The Art of War, the brave person is the one who is often intensely moral, undismayed by danger and demonstrably willing to kill and die for his beliefs. In the competition between groups of genetic strangers, such as empires and nations or transnational movements and ideologies, the society with greater bravery will win, all things being equal. Consider the American revolutionaries who, defying the greatest empire of the age, pledged "our lives, our fortunes, our sacred honor" in the cause of "Liberty or Death," where the desired outcome was highly doubtful.

How many lives should a leader be willing to sacrifice to remove a murderous dictator like Muammar Gaddafi or Saddam Hussein? Most of the theories and models that researchers use to study conflicts like the Libyan or Iraq wars assume that civilians and leaders make a rational calculation: If the total cost of the war is less than the cost of the alternatives, they will support war. But recent studies by psychologist Jeremy Ginges and myself, carried out with the support of the National Science Foundation and the Defense Department, suggest those models are insufficient. Our surveys of people confronted with violent situations in the US, Middle East and Africa suggest that people consistently ignore quantifiable costs and benefits, relying instead on "sacred values."

In one study, we asked 656 Israeli settlers in the West Bank about the dismantlement of their settlement as part of a peace agreement with Palestinians. Some subjects were asked about their willingness to engage in nonviolent protests, whereas others were asked about violence. Besides their willingness to violently resist eviction, the subjects rated how effective they thought the action would be and how morally right the decision was. If the settlers are making the decision rationally, in line with mainstream models, their willingness to engage in a particular form of protest should depend mostly on their estimation of its effectiveness. But if sacred values come into play, that calculus should be clouded.

When it came to nonviolent options such as picketing and blocking streets, the rational behavior model predicted settlers' decisions. But in deciding whether to engage in violence, the settlers defied the rational behavior models. Rather than how effective they thought violence would be in saving their homes, the settlers' willingness to engage in violent protest depended only on how morally correct they considered that option to be. We found similar patterns of "principled" resistance to peace settlements and support for violence, including suicide bombings, among Palestinian refugees who felt "sacred values" were at stake, such as the recognizing their moral right of return to homes in Israel even if they expressed no material or practical interest in actually resettling.

In a series of follow-up surveys among U.S. and Nigerian participants, we confronted subjects with hypothetical hostage situations and asked them if they would approve of a solution -- which was either diplomatic or violent -- for freeing the prisoners. The chance of success varied in terms of the number of hostages who might die. For example, in one version of the survey, when told that their action would result in all hostages being saved, both groups endorsed the plan presented to them. Told that one hostage would die, however, most "diplomats" became reluctant to endorse the proposed response. Those opting for military action had no such qualms. In fact, the most common response suggested that they would support military action even if 99 of 100 hostages died as a consequence.

These and other studies suggest that most societies have "sacred rules" for which their people would fight and risk serious loss and even die rather than compromise. If people perceive one such rule to have been violated, they may feel morally obliged to retaliate against the wrongdoers -- even if the retaliation does more harm than good. Ongoing neuroimaging studies by our research group led by Gregory Berns and his neuroeconomics team at Emory University indicates that sacred values are processed in those parts of the brains that deal with rule-governed behavior (rather than cost-benefit analyses), and are associated with greater emotional activity consistent with sentiments of "moral outrage" when participants perceive a violation of sacred values. In the hostage situation, the abductors were threatening to violate the sacred rule against killing innocent people. That rule was so strong for the participants that they felt morally obliged to meet violence with violence, regardless of the outcome. This is little different from Mr. Obama's seemingly heartfelt sentiment that "as president, I refused to wait for the images of slaughter and mass graves before taking action."

Every military strategist understands that even the most thought out military plan usually dissolves upon contact with the enemy, and that war generally carries a high measure of uncertainty and likelihood of "unintended consequences." But even the decision to go to war is never just a product of reason and rational calculation, and thus never just "politics by other means," despite what von Clausewitz famously stated in his classic study On War. This, the sentiment of a Prussian regimental officer in the post-Napoleonic era of state interests and strategies to rearrange "the balance of power," disastrously misguided European elites into believing that wars could be started and pursued to a desired end by careful planning (while granting that in the fog of war events sometimes spin out of control). Many of our political and military leaders still believe in this Clausewitz delusion: it's a mainstay in the curricula of U.S. war colleges and the international relations departments of top U.S. universities, and of most military and foreign affairs staffs in the world.

In truth, war is almost always an emotional matter of status and pride, of shedding blood and tearing the flesh of others held dear, of dread and awe and of the instinctual needs to escape from fear, to dominate and to avenge. But war is most profoundly an expression of that peculiar aspect of human nature that expresses our animal origins but which also distinguishes our species from all others that struggle and fight for survival: it defines "who we are" in the search for significance in an otherwise uncaring universe.

Unlike other creatures, humans define the groups to which they belong in abstract terms. Often they kill and die not in order to preserve their own lives or those of the people they love, but for the sake of an idea -- the conception they have formed of themselves. Call it love of group or God, it matters little in the end. This is the "the privilege of absurdity; to which no living creature is subject, but man only'" of which Thomas Hobbes wrote in Leviathan. It is a human trait that likely will not change, and which political leaders must learn to manage -- however inescapably murky -- so that their people will endure in a world where an end to war is no more likely than unending day. But to insist that war make perfect rational sense, where means cost effectively lead to clear and practical political ends, may impose an inhuman task that any leader can only sidestep or fudge.

Scott Atran, an anthropologist at France's National Center for Scientific Research, the University of Michigan and John Jay College, is the author of Talking to the Enemy.