The roots of war. (Flip Side).

Only three types of creatures engage in warfare--humans, chimpanzees, and ants. Among humans, warfare is so ubiquitous and historically commonplace that we are often tempted to attribute it to some innate predisposition for slaughter--a gene, perhaps, manifested as a murderous hormone. The earliest archeological evidence of war is from 12,000 years ago, well before such innovations as capitalism and cities and at the very beginning of settled, agricultural life. Sweeping through recorded history, you can find a predilection for warfare among hunter-gatherers, herding and farming peoples, industrial and even post-industrial societies, democracies, and dictatorships. The good old pop-feminist explanation--testosterone--would seem, at first sight, to fit the facts.

But war is too complex and collective an activity to be accounted for by any warlike instinct lurking within the individual psyche. Battles, in which the violence occurs, are only one part of war, most of which consists of preparation for battle--training, the manufacture of weapons, the organization of supply lines, etc. There is no plausible instinct, for example, that could impel a man to leave home, cut his hair short, and drill for hours in tight formation.

Contrary to the biological theories of war, it is not easy to get men to fight. In recent centuries, men have often gone to great lengths to avoid war--fleeing their homelands, shooting off their index fingers, feigning insanity. So unreliable was the rank and file of the famed eighteenth century Prussian army that military rules forbade camping near wooded areas: The troops would simply melt away into the trees. Even when men are duly assembled for battle, killing is not something that seems to come naturally to them. As Lieutenant Colonel Dave Grossman argued in his book On Killing: The Psychological Cost of Learning to Kill in War and Society (Little, Brown, 1995), one of the great challenges of military training is to get soldiers to shoot directly at individual enemies.

What is it, then, that has made war such an inescapable part of the human experience? Each war, of course, appears to the participants to have an immediate purpose--to crush the "Hun," preserve democracy, disarm Saddam, or whatever--that makes it noble and necessary. But those who study war dispassionately, as a recurrent event with no moral content, have observed a certain mathematical pattern: that of "epidemicity," or the tendency of war to spread in the manner of an infectious disease. Obviously, war is not a symptom of disease or the work of microbes, but it does spread geographically in a disease-like manner, usually as groups take up warfare in response to war-like neighbors. It also spreads through time, as the losses suffered in one war call forth new wars of retaliation. Think of World War I, which breaks out for no good reason at all, draws in most of Europe as well as the United States, and then "reproduces" itself, after a couple of decades, as World War II.

In other words, as the Dutch social scientist Henk Houweling puts it, "one of the causes of war is war itself." Wars produce war-like societies, which, in turn, make the world more dangerous for other societies, which are thus recruited into being war-prone themselves. Just as there is no gene for war, neither is there a single type or feature of society--patriarchy or hierarchy--that generates it. War begets war and shapes human societies as it does so.

In general, war shapes human societies by requiring that they possess two things: one, some group or class of men (and, in some historical settings, women) who are trained to fight; and, two, the resources to arm and feed them. These requirements have often been compatible with patriarchal cultures dominated by a warrior elite--knights or samurai--as in medieval Europe or Japan. But not always: Different ways of fighting seem to lead to different forms of social and political organization. Historian Victor Hansen has argued that the phalanx formation adopted by the ancient Greeks, with its stress on equality and interdependence, was a factor favoring the emergence of democracy among nonslave Greek males. And there is no question but that the mass, gun-wielding armies that appeared in Europe in the seventeenth century contributed to the development of the modern nation-state--if only as a bureaucratic apparatus to collect the taxes required to support these armies.

Marx was wrong, then: It is not only the "means of production" that shape societies, but the means of destruction. In our own time, the costs of war, or war-readiness, are probably larger than at any time in history, in relation to other human needs, due to the pressure on nations not only to maintain a mass standing army--the United States supports about a million men and women at arms--but to keep up with an extremely expensive, ever-changing technology of killing. The cost squeeze has led to a new type of society perhaps best termed a "depleted" state, in which the military has drained resources from all other social functions. North Korea is a particularly ghoulish example, where starvation coexists with nuclear weapons development. But the USSR also crumbled under the weight of militarism, and the United States brandishes its military might around the world while, at this moment, cutting school lunches and health care for the poor.

"Addiction" provides only a pallid and imprecise analogy for the human relationship to war; parasitism--or even predation--is more to the point. However and whenever war began, it has persisted and propagated itself with the terrifying tenacity of a beast attached to the neck of living prey, feeding on human effort and blood.

If this is what we are up against, it won't do much good to try to uproot whatever war-like inclinations may dwell within our minds. Abjuring violent speech and imagery, critiquing masculinist culture, and promoting respect for human diversity--all of these are worthy projects, but they will make little contribution to the abolition of war. It would be far better to think of war as something external to ourselves, something which has to be uprooted, everywhere, down to the last weapon and bellicose pageant.

The "epidemicity" of war has one other clear implication: War cannot be used as a means to prevent or abolish war. True, for some time to come, urgent threats from other heavily armed states will require at least the threat of armed force in response. But these must be very urgent threats and extremely restrained responses. To indulge, one more time, in the metaphor of war as a kind of living thing, a parasite on human societies: The idea of a war to end war is one of its oldest, and cruelest, tricks.

Barbara Ehrenreich is a columnist for The Progressive. She is the author of "Nickel and Dimed: On (Not) Getting By in America" (Metropolitan Books, 2001) and "Blood Rites: Origins and History of the Passions of War" (Henry Holt, 1997).