CHAPTER THREE
Does Resource Scarcity Make Us Fight? (No, Not Necessarily)
Entering the lobby of the Peabody Museum of Archaeology and Ethnology at Harvard University, you encounter a large glass case enclosing a fringed deerskin shirt. At first glance the shirt looks raggedy and unremarkable. But a closer look reveals faded embroidered images of men pierced by arrows, blood dripping from their wounds. According to a caption, Meriwether Lewis and William Clark collected this garment during their famous expedition across North America from 1804 to 1806. The shirt belonged to a warrior from a Northern Plains tribe, and each of these gory embroidered figures depicts one of his victories.
I think that Steven LeBlanc, director of collections at the Peabody, placed the shirt in the lobby to send a message: indigenous people in the Americas were killing each other before they made contact with Europeans. LeBlanc has adorned his office walls with more tribal war paraphernalia, including slings from Asia Minor and the Andes, body armor from New Guinea, and shields and spear-throwers from the Australian Outback. LeBlanc is bearded, barrel-chested, and heartily cheerful when denigrating those who view warfare as a relatively recent behavior. “Scholars who insist that war did not exist in the distant past,” he says, have “no interest in getting to the real evidence.”
Like his Harvard colleague Richard Wrangham, LeBlanc is an adamant advocate of the view that war is ancient and innate. In his 2003 book Constant Battles: Why We Fight, co-written with the journalist Katherine Register, LeBlanc calls war “a common and almost universal human behavior that has been with us as we went from ape to human.” But LeBlanc blames war primarily on demographic and environmental factors—in particular the tendency of a population to outgrow its environment’s capacity to nourish everyone.
“Since the beginning of time,” he writes, “humans have been unable to live in ecological balance. No matter where we happen to live on Earth, we eventually outstrip the environment. This has always led to competition as a means of survival, and warfare has been the inevitable consequence of our ecological-demographic propensities.” I italicized “inevitable” to show how deterministic LeBlanc’s view is. Warfare invariably erupts, he believes, as a result of population surges, droughts, and other conditions that lead to scarcity of food. During the modern era, he says, the primary focus of armed conflict has simply shifted from food to energy sources, notably fossil fuels.
LeBlanc’s explanation of war is basically the “war-is-in-our-genes” thesis plus a dose of Thomas Malthus. A British clergyman and scholar, Malthus based what he called his “melancholy” theory on two axioms: “First, That food is necessary to the existence of man. Secondly, That the passion between the sexes is necessary.” Malthus predicted that population, “when unchecked,” will rapidly outpace the Earth’s food-producing capacity. As a result, he said, many humans would die prematurely as a consequence of famine, disease, and fighting. This hypothesis, published in 1798, inspired Darwin’s theory of natural selection, which assumes that all creatures produce excess offspring, only the fittest of which survive long enough to reproduce.
Malthusian theories of war are quite popular. In his 822-page book War in Human Civilization, published in 2006, the Israeli political scientist Azar Gat weighs countless theories of warfare’s causation before finally favoring “the competition over scarce resources.” In principle, this view should perhaps engender more optimism than purely biological theories. Malthusian models imply that humans wage war not simply because their genes compel them to do so but for rational reasons: societies fight for survival and security. This perspective, in fact, gives LeBlanc confidence that we can overcome war. Two key steps to reducing war’s probability, he claims, are controlling population growth and finding alternatives to fossil fuels. “I was just in Germany,” LeBlanc informed me happily, “and there are windmills everywhere!”
But what if we cannot curb our population growth and consumption of fossil fuels and other resources quickly enough, or at all? Does that mean we are doomed to wage war? Many pundits on the left and right seem to think so. They warn that global warming—unless we take drastic steps to stop it—will trigger catastrophic conflicts. I understand these concerns. According to some climate forecasts, surging sea levels and intensifying storms might create an enormous refugee crisis by driving people from low-lying coastal lands. Even more worrisome is the fact that climate change might produce worldwide shortages of fresh water. Climatologists predict that droughts will become more frequent and intense, already dry regions will become more parched, and water supplies from seasonal snowmelts will diminish or even vanish.
Many of the world’s poorest people now lack clean water for drinking, sanitation, and agriculture, and water disputes are already exacerbating tensions in troubled regions. Israel controls rivers and aquifers upon which Palestinians and Jordanians depend. Pakistan fears that the water it needs for agriculture will be reduced by a dam project in India. India in turn is anxious about dam projects in China. African countries bordering the Nile are bickering over water rights. Droughts are thought to be exacerbating lethal conflicts in the Sudan and other African nations, which also have some of the world’s fastest-growing populations. Global warming could make such conflicts “more rather than less likely,” the British home secretary John Reid stated in 2006. The environmental scientist Lester Brown, founder of the respected Worldwatch Institute, warns that unless we drastically reduce our carbon emissions and population growth, “civilization itself could disintegrate.”
One of the ironies of the recent Bush administration is that while officials like Vice President Dick Cheney downplayed global warming, the Pentagon was quietly concluding that it posed a tremendous threat to security. One Defense Department study concluded that climate change could trigger “desperate, all-out wars over food, water, and energy supplies.” The study asserts that “wars over resources were the norm until about three centuries ago. When such conflicts broke out, 25 percent of a population usually died. As abrupt climate change hits home, warfare may again come to define human life.” As evidence for this thesis, the study cited the writings of “Harvard archaeologist Steven LeBlanc.”
THE CIRCUMSCRIPTION THEORY OF WAR
I reject the view that scarcity of resources leads “inevitably,” as Steven LeBlanc puts it, to warfare. Clearly, we must find more sustainable means of living, for the sake of humanity and the rest of nature. But our history and prehistory simply do not support the pessimistic conclusion that resource scarcity and war are inevitably or inextricably connected. Malthusian factors have played a role in some conflicts, but not in others. Again, war cannot be pinned on any one definite cause.
But before showing the flaws of the Malthusian explanation of war, let me give it its full due. As I point out in chapter one, war arose not millions of years ago (as LeBlanc claims) but less than twelve thousand years ago, as our ancestors started abandoning their nomadic ways and settling down in lands with plentiful game, edible plants, and water. Populations surged in these regions as people domesticated animals and cultivated wild cereals and other crops on fertile land surrounding major rivers—notably the Tigris, Euphrates, Nile, Indus, and Yellow. Farmers accumulated surplus food, crafted increasingly sophisticated tools, and built permanent dwellings out of wood and stone, all of which meant they had more worth stealing or defending.
For most of human prehistory, people could simply walk away from disputes, because land was so plentiful. But according to the “circumscription theory” of the origin of civilization, proposed by the anthropologist Robert Carneiro in 1970, some especially fertile regions were bounded by mountain ranges, deserts, seas, or other geographical obstacles that made dispersal difficult, if not impossible. Within these regions, small farming communities began to fight, conquer, and form alliances with each other. In this way, Carneiro suggests, villages merged into chiefdoms, which in turn fused into the first great civilizations in Mesopotamia, Egypt, India, and China, and later in Mesoamerica and the Andes.
Ancient states, as described by Carneiro, resembled protection rackets. Powerful warlords promised to protect people from famine and violence in exchange for labor, military service, taxes, and other payments. And they killed those who spurned their offer. In other words, the warlords represented the primary threat to the people they protected. “Force, and not enlightened self-interest, is the mechanism by which political evolution has led, step by step, from autonomous villages to the state,” Carneiro writes.
Mesopotamia, Egypt, and other primordial states boosted agricultural production by constructing large-scale irrigation systems, as well as roads and storage facilities. Yet states and smaller societies still often outgrew the capacity of their lands to support them. Some brought on their own problems by over-farming, over-grazing, and over-foresting, and others were felled by a shift in climate that diminished food production. Self-induced ecological damage plus a long-term drought are thought to have contributed to the collapse of the Mayan civilization in Mesoamerica and the Anasazi culture in the southwest United States.
These examples would seem to lend support to the Malthusian theory. So do some smaller-scale societies, such as the Chumash, hunter-gatherers who settled along the coast of southern California as early as ten thousand years ago. Chumash skeletons dating back thousands of years—well before the arrival of Europeans—display signs of violence, including skull fractures and embedded arrow and spear points. Analysis of tree rings and other evidence indicate that fighting among the Chumash escalated during periods of drought.
A different sort of climate change destroyed a once-thriving Norse culture in Greenland. Norse sailors colonized the island in the tenth century CE and built a replica of their homeland, complete with farmland, pastures for cattle and other livestock, stone houses, and churches. In retrospect, the community benefited from several centuries of relatively warm weather in the northern hemisphere. But it could not survive the Little Ice Age, a cold spell that froze Europe and the North Atlantic in the fourteenth century. Excavations of the Norse settlements reveal violence in the society’s twilight.
Even the Crusades, the quintessential religious conflict, could be said to stem in part from Malthusian conditions. By the eleventh century, most European landowners practiced primogeniture, bequeathing their estates to their first born sons; this custom had produced a large population of rootless young men, many of whom had trained to be knights. These knights offered their martial services to whomever would pay them. In 1095, Pope Urban II issued the following proclamation to these warriors:
“For this land which you now inhabit, shut in on all sides by the sea and the mountain peaks, is too narrow for your large population; it scarcely furnishes food enough for its cultivators. Hence it is that you murder and devour one another, that you wage wars, and that many among you perish in civil strife. Let hatred, therefore, depart from among you; let your quarrels end. Enter upon the road to the Holy Sepulcher; wrest that land from a wicked race, and subject it to yourselves.”
Thus did Pope Urban launch the First Crusade, in a speech that anticipated Malthus and even circumscription theory. The Pope’s letter seems to support LeBlanc’s claim that competition for resources fuels conflicts that on the surface seem to have religious, political, or ethnic bases.
MALTHUSIAN EXCEPTIONS
But other examples contradict the Malthusian model of war. The anthropologist Keith Otterbein notes that some early agricultural societies—even in circumscribed areas subject to population pressure—lived peacefully for centuries or longer. One of the oldest known settlements was Abü Hureyra, near the Euphrates River. Excavations have revealed that people began erecting permanent dwellings and cultivating grains in this fertile region 11,500 years ago. Life wasn’t easy; bones of male and female inhabitants show signs of hard labor and disease. But for more than four thousand years, generations came and went with no signs of warfare. And contrary to the claim of Carneiro that the first city-states were founded through violent conquest, ancient Sumerian cities like Ur and Uruk, in eastern Mesopotamia, thrived for centuries before constructing fortifications and amassing armies. Archaeological digs reveal a similar pattern in the evolution of primordial agricultural societies in China and the Americas, which were circumscribed and densely populated but did not engage in significant warfare for many generations after being founded.
Conversely, some simple tribal societies fought in the absence of dense population and deprivation. To wit, Australian Aborigines were nomadic hunter-gatherers, not farmers, and yet ten thousand years ago they carved rock drawings that seem to depict them battling each other. Indeed, some tribal people recognized war as a cause of scarcity rather than vice versa. One warrior in New Guinea told an ethnographer: “War is bad and nobody likes it. Sweet potatoes disappear, pigs disappear, fields deteriorate, and many relatives and friends get killed.”
Napoleon Chagnon has always adamantly denied that the Yanomamö fought over land, game, and other resources. If anything, he argues, Yanomamö warfare is more intense in areas with the sparsest populations and most plentiful food. “If one insists on a narrow cause-effect relationship between warfare intensity and protein consumption,” Chagnon writes, “a much stronger case could be made that those people who have the highest levels of protein consumption are the ones who are the most warlike.”
All these cases suggest that there is no clear-cut correlation between resource scarcity and warfare. So does a comprehensive study of a wide range of societies carried out by the anthropologists Carol and Melvin Ember. For decades, this husband and wife team oversaw the Human Relations Area Files, which contains detailed information gathered over the past two centuries on more than three hundred and sixty simple and complex societies.
When I interviewed them in their offices at Yale University, they kept interrupting, challenging, and correcting each other. But they agreed that their cross-cultural analysis generates several significant conclusions. First, war is not restricted to states, chiefdoms, and other complex societies; some hunter-gatherers have clearly waged war, although others have never been observed fighting or do so only occasionally. The enormous variability of warfare both within and between cultures, Melvin said, suggests that “we are not dealing with genes or a biological propensity” for war.
The Embers also turned up no evidence for the scarce-resources theory of war. Melvin was initially inclined to believe the theory, because in the 1980s he found a link between population density and warfare among tribal New Guineans who practiced small-scale farming. The victors in war typically seized land from losers. But when Carol and Melvin examined 186 cultures from all over the world, they did not find support for the scarce-resources theory, at least not in its simplest form. The cultures, which represent different historical periods and levels of social development, include ancient civilizations such as the Babylonians, Aztecs, and Romans; hunter-gatherers such as the Aleut and !Kung; more complex tribal societies such as the Maori and Yanomamö; and even modern ethnic groups such as the Albanians and Kurds.
War among these cultures did not break out, according to the Embers, as populations surged and subside as populations fell. Nor was there a correlation between warfare and persistent scarcity of food and other resources. “Chronic scarcity has no effect whatsoever on warfare frequency,” Carol told me. What the Embers did find was something more subtle. The strongest correlates of warfare were unpredictable natural disasters—floods, droughts, earthquakes, insect infestations—that had disrupted food supplies in the past.
The Embers are careful to note that it is not the disasters themselves that precipitated war, but the memory of past disasters and hence the fear of future ones. This is a key point. The Embers write: “Societies with only the threat of disasters, with a memory of unpredictable disasters but no actual disasters during a twenty-five-year period, fought very frequently.”
In other words, wars stemmed from factors that were not demographic and ecological so much as psychological. If a war to avoid imminent starvation is a war of necessity, most wars were not wars of necessity. They were wars of choice, motivated by a fear of the possibility of scarcity. What’s most disconcerting, I think, about the fear-of-scarcity motive is that it can apply to any society at any time. No matter how prosperous we are, we can always imagine some disaster—including, of course, war itself—that will strip us of everything. So we go to war, which, ironically, often inflicts on us a disaster worse than what we feared.
Fear—as well as ambition and greed—no doubt motivated some ancient chiefs, kings, and emperors to keep expanding their forces, both to conquer new lands and maintain order within their borders. Hence an increasing proportion of a society’s human power was diverted from farming to fighting. As a result, food production per capita dropped, leading to greater shortages and social unrest, which provoked rulers into building up their forces further and repressing civilians more violently. Scholars such as the economist Thomas Homer-Dixon have shown that this destabilizing cycle—in which warfare exacerbates resource scarcity which in turn instigates more war—contributed to the collapse of a wide variety of ancient societies, from the Roman and Mayan empires to the chiefdoms of Easter Island.
PROS AND CONS OF THE INDUSTRIAL REVOLUTION
Fear of scarcity has motivated some modern nations to wage war. The desire to secure resources, especially fossil fuels, played a role in imperial Japan’s violent conquests in the 1930s, Iraq’s invasion of Kuwait in 1990, and the counter-attack by the U.S. a year later. But actual scarcity of resources (as opposed to fear of future scarcity) explains modern international warfare even less than it explains pre-state conflicts.
That may be because modern states have been astonishingly successful at escaping what some scholars have called the “Malthusian trap.” Through most of our history, the vast majority of humanity lived a hand-to-mouth existence; only a minuscule elite was wealthy. Average standards of living remained stagnant for the first millennium CE, and rose only slightly over the next eight hundred years. In 1800, the average income in Western Europe was slightly less than the average income in modern Africa, the world’s poorest region.
Since then, however, the percentage of humanity living in poverty has fallen dramatically. About one sixth of the global population, or 1.4 billion people, now survive on less than $1.25 a day, the U.N.’s definition of “extreme poverty.” (The U.S. definition of poverty for Americans is less than $30 a day.) The number of extremely poor people is shamefully high, and yet as a percentage of the population it is extremely low compared to historical levels. Over the past two centuries the world’s population has grown six-fold and per-capita income has grown nine-fold, contradicting Malthus’s dire forecasts. Per capita income has skyrocketed in Europe and the United States, by fifteen-fold and twenty-five-fold. Meanwhile, life expectancies have doubled as a result of public-health measures to almost seventy years—almost eighty in first-world nations such as Japan and the U.S.
Our material progress can be traced back to the Industrial Revolution, which began in Europe and jump-started a global economic surge that continues to this day. The Industrial Revolution generated a host of productivity-boosting innovations: steam engines, railroads, mechanized looms, cotton gins, nitrogen-based fertilizers, telegraphs, light bulbs, and gasoline-powered automobiles, trucks, and farm equipment. Unlike finite resources such as gold, oil, and land, most scientific innovations can in principle be infinitely replicated (albeit limited by, say, fuel needs and materials). Hence they rapidly spread around the world, yielding economic benefits that spur further innovation and growth.
Contrary to complaints by critics of capitalism and imperialism, economic growth has not been an entirely zero-sum game, in which the wealthy and powerful prosper at the expense of the poor. In fact, the “Green Revolution,” which boosted agricultural production in third-world countries, demonstrates how prosperous nations can help developing ones: in the 1940s, the Rockefeller Foundation funded research to find higher-yield varieties of grain. The program helped transform Mexico, the first test bed for the new crops, from a net importer of grain to an exporter in just twenty years. Later, India multiplied its wheat production five-fold in thirty years, outpacing its population growth.
Unfortunately, the decline in poverty over the past two centuries has not been matched by a comparable decline in militarism and war, a fact that pokes a hole in the Malthusian explanation of war’s roots. The Industrial Revolution gave us industrial war, in which we fought with machine guns, tanks, bombers, battleships, poison gas, and nuclear bombs. World Wars I and II embroiled the world’s most prosperous nations. These terrible conflicts often resulted in food shortages, especially among the poor and powerless. In her 2010 book Churchill’s Secret War, the journalist Madhusree Mukerjee provides overwhelming documentary evidence that in the early 1940s, at least 3 million Indians starved to death as a direct result of England’s diversion of grain from India to British civilians and troops. Another case of war causing scarcity rather than vice versa.
THE STATISTICS OF DEADLY QUARRELS
Malthus’s “melancholy” theory certainly provides insights into the history of humanity. His timing was terrible, however, because almost as soon as he had proposed his idea, humanity started proving that it could escape the boom-bust cycles of population surges and crashes. And yet war continued.
Malthus was hardly alone in proposing an economic explanation for conflict. In the mid-nineteenth century, an obscure German scholar living in London—ground zero of the Industrial Revolution—proposed a rival theory. The cause of conflict, Karl Marx proposed, was not scarcity per se, but economic inequality, which was the inevitable consequence of capitalism and other economic systems based on private ownership. As long as capitalism persists, Marx predicted, so will war between haves and have-nots. Communism has not exactly solved the problem of war, any more than capitalism has, but could Marx’s explanation of conflict be correct?
One of the most rigorous attempts to test theories of war—including those of Malthus and Marx—was carried out in the middle of the last century by the British physicist Lewis Fry Richardson. Richardson spent his early career as a weather researcher for the British Meteorological Service. His 1922 book Weather Prediction by Numerical Process laid the foundation for modern forecasting and anticipated many of the concepts and methods of chaos theory.
A pacifist and conscientious objector, Richardson served on a Quaker ambulance unit during World War I. In 1920, fearing that the military would use his forecasts for planning poison-gas attacks, he resigned from the British Meteorological Service when it became a branch of the British Armed Forces. For the rest of his life, Richardson studied war, modeling it with the same mathematical methods with which he had analyzed weather. He compiled data on war from an enormous number of sources, ranging from the Encyclopedia Britannica to newspapers and obscure political journals. He was still working on his magnum opus, The Statistics of Deadly Quarrels, when he died in 1953. Quincy Wright, another war scholar, edited Richardson’s manuscript and got it published in 1960.
Deadly Quarrels lists and analyzes hundreds of lethal conflicts that occurred from 1815 through 1945, ranging from homicides perpetrated by criminal gangs up to the First and Second World Wars. Other major “quarrels” include China’s Taiping Rebellion of 1851 to 1864, in which as many as 20 million people died; the Great War in La Plata of 1865-1870, which culminated in the extermination of more than 80 percent of Paraguayans; and the Zulu revolt against the British in 1906.
Richardson devotes a chapter to economic causes of war, including those postulated by Malthus and by Marx. Richardson finds that, contra Marx, “rich and poor were usually intermingled” on each side of a conflict, including the Russian Revolution itself. Richardson searches for evidence of other possible overriding economic factors, such as taxation, population pressure, restrictions on trade or migration, the desire for new territory, and what he calls the “fall from comfort into poverty.” Because he identifies multiple causes for individual wars, Richardson comes up with a list of 244 causes for eighty-three major wars. Only 29 percent of the 244 causes are economic, and economics played no role at all in almost one third of the wars. Nor does Richardson find evidence that population growth increased the risk of conflict. In short, his massive statistical analysis provides scant support for Marxist or Malthusian explanations of war.
ECO-SOLUTIONS TO WAR FALL SHORT
In chapter two, I noted that biological theories of war have inspired “bio-solutions,” ranging from brain implants that suppress violent impulses to sporting events that might vent aggression. In the same way, Marxist and Malthusian theories have inspired solutions that counteract supposed ecological and economic causes of war. Let’s call these “eco-solutions.”
One eco-solution entails reducing violence through socialism. The psychologists Margo Wilson and Martin Daly, for instance, have sought to explain why Canada’s homicide rate is only about a third of that in the States, and why rates of homicide vary widely from region to region within each country. The best predictor of high homicide rates in a region, Daly and Wilson assert, is income inequality. As a measure of such inequality, Daly and Wilson employ the so-called Gini index (named after its originator, the Italian statistician Corrado Gini), which ranks inequality on a scale ranging from 0.0 to 1.0. A region in which everyone has exactly the same income would have a Gini score of 0.0, whereas a region in which one person makes all the money would have a score of 1.0.
Daly and Wilson find a strong correlation between high Gini scores and high homicide rates in Canadian provinces and U.S. counties. High Gini scores serve as better predictors of deadly violence than low average income or high unemployment do. Basically, Daly and Wilson are blaming homicides not on poverty, exactly, but on the ancient tug of war between haves and have-nots. The income-inequality hypothesis, Daly and Wilson contend, can account for the “radically different national homicide rates” in the U.S. versus Canada. Canada, after all, has broader social-welfare programs and hence fewer economic disparities than the United States. The implication of their hypothesis is that societies can reduce homicide rates via a more equitable economic system, perhaps with higher taxes for the wealthy and more generous welfare programs for the poor.
While these programs are, I believe, worth pursuing in and of themselves, scholars examining other nations around the world have found less evidence linking economic inequality to homicides. And of course some socialist leaders, notably Stalin, Mao, and even Hitler, who built political support for the Nazi party with generous welfare programs, have carried out appalling crimes against humanity.
The economist Jeffrey Sachs holds that the best way to reduce war, terrorism, and other forms of violence is to reduce poverty, and the best way to reduce poverty is via “capitalism with a human face.” In the late 1990s, Sachs helped U.N. officials design the Millennium Development Goals, a plan for eliminating extreme poverty. The plan calls for affluent nations to give impoverished countries grants for education, healthcare, transportation, and communication. Then, according to Sachs, business investments plus international aid, which Sachs calls “Enlightened Globalization,” could help these regions become self-sufficient.
I agree with Sachs that affluent nations have a moral obligation to help those mired in poverty. But I don’t share his confidence that globalization and aid alone will reduce conflicts fueled by religious, ethnic, and political divisions. Even Sachs acknowledges that economic development conducted in the name of globalization often makes the rich richer and the poor poorer—and incites conflict. In northern India, for example, the government has forced thousands of poor farmers off their land to make way for a multinational aluminum-mining operation, triggering violent protests met with even more violent government crackdowns.
I also have doubts about a different eco-solution to war proposed by the journalist and environmental activist Bill McKibben. In his 2010 book Eaarth (the extra “a” indicates our planet’s irrevocably altered nature), McKibben argues that unchecked global warming will plunge us into wars over water, food, and other necessities. He cites, among other sources, the Pentagon report that I mentioned earlier in this chapter. To avoid this fate, he says, we need to reject globalization and big government and create small, self-sustaining communities that generate their own energy, grow their own organic food, and even organize their own militias for self-defense.
Although I agree with McKibben that we need to cut back on our consumption of fossil fuels and other resources, I don’t think we need to scale back civilization to accomplish that goal. Big government and big business, in spite of their manifest flaws, have their upsides. The Clean Water and Air Acts, the Endangered Species Act, and other federal laws and regulations have helped clean up the environment. In the 1980s, the Hudson River was filthy, filled with sewage and industrial toxins. But I have been swimming in it with my kids since the late 1990s. The air in New York City is much cleaner than it was decades ago. Multinational corporations have brought us green technologies like the Prius (which gets more than forty miles per gallon) and are rapidly improving the efficiency of solar and wind energy.
All eco-solutions, in the end, rest on a flawed assumption: that resource scarcity equals war. On the other hand, as the Embers have shown, fear of scarcity—and fear of war itself—can indeed provoke war. I’m thus concerned about the warnings of McKibben and other green activists, the pronouncements that unless we take drastic steps to change our behavior we will descend into violent, civilization-destroying chaos. Rather than inspiring people to install solar panels, grow their own vegetables, and support federal research on clean energy, these alarming prophesies might provoke people into supporting higher defense budgets and even stockpiling firearms as protection against the impending apocalypse. In this way, prophesies of wars over water, food, and other resources could become self-fulfilling.
THE ESSENTIAL MYSTERY OF WAR
The British historian John Keegan, one of the world’s leading authorities on war, notes that theories of war generally fall into one of two categories. On one side are “naturalist” explanations, which attribute lethal group conflict to innate factors. On the other side are “materialist” theories, which blame conflict on economic and ecological factors. I think that neither naturalist nor materialist explanations really capture war’s complexity.
Scholars have sought other explanations that can supplement if not replace naturalist and materialist theories. Carol and Melvin Ember, for example, investigated whether societies that encourage young boys to be tough and physically aggressive tend to be more warlike, but warfare seems to promote cultural machismo rather than vice versa. Lewis Fry Richardson turned up little support for other popular theories. Arms races are not strongly correlated with wars, nor do trade or a shared language make nations less likely to fight. Richardson reported two statistically significant, but not terribly surprising patterns: neighbors are more likely to fight each other than non-neighbors, and new wars are more likely to break out in the vicinity of warring regions.
Richardson’s statistics display a Poisson distribution, a mathematical function that describes phenomena whose amplitude is inversely proportional to their frequency, but that otherwise occur in a random fashion. Earthquakes, storms, and floods all conform to Poisson distributions—and so do wars, according to Richardson’s data. His conclusions corroborate a 1957 study by the Russian American sociologist Pitirim Sorokin, who sees no clear-cut pattern in outbreaks of war going back as far as 500 BCE Wars, overall, are not associated with any particular type of culture, or with economic expansion or decline.
These analyses highlight the essential mystery of war. Researchers have desperately searched for war’s causes, but they have found both too many and too few. War has been blamed on a dizzying array of factors, but wars are so diverse that you can find evidence to support or contradict almost any theory. War has even been blamed on the desire for peace! The historian David Bell points out that many modern leaders—from Napoleon to Woodrow Wilson—have waged war with the stated goal of attaining universal peace. “Dreams of an end to war may be as unexpectedly dangerous as they are noble,” Bell writes, “because they seem to justify almost anything done in their name.”
Many conditions appear to be sufficient for war to occur, but none are necessary. Some societies remain peaceful even when significant risk factors are present, such as high population density, resource scarcity, and economic and ethnic divisions between people. Conversely, other societies fight in the absence of these conditions. Which leads us to the next question: how can this complex pattern of social behavior possibly be explained?