We can debate the various causes and deny climate change. Or we can all just agree that this summer in Iraq and Afghanistan the mercury is likely to top 120 degrees Fahrenheit.
In the shade.
Of a dry, crowded nations.
With few reliable sources of water.
In that case it’s worth considering how natural forces compound to shape already uncertain behavior and trigger the instincts with which humans evolved in Africa.
Drought and thirst and heat can expose the dark side within mammals of the savanna, and bring latent aggression to the surface. Shriveling water holes cause abnormal behavior even among supposedly exclusive herbivores. I’ve seen hippos gnaw carcasses and thirsty zebra kick to death a baby wildebeest while anxious adult elephants crush life from one of their own infants. But of all water-dependent beasts one parched animal stands out as particularly, and calculatingly, lethal.
The thirsty primate carefully plots when and how to attack. When Kenyan relief workers opened a water tanker truck for drought-struck villagers near the Sudan border, vervet monkeys gathered in the trees, descended from branches, and for the next two hours fought, wounded, and died for access to the last precious drops. Chimpanzee and bonobo–who most closely share our own DNA–selectively attack their rivals over access to vanishing resources. Yet of Earth’s 233 primate species, only two left the forests to endure and inhabit the arid African savanna. It would have been illegal and immoral to subject humans or animals in captivity to extreme thirst for observation, but in the wild ecologists could study behavior of our nearest dryland relative, baboons, as an isolated troop confronted the end of water.
It was eerie and unnerving to watch. As one old and deep crocodile-infested pool evaporated, baboons adapted in ways remarkably similar to humans. Initially the troop kept its integrity, bonding across kinship lines by grooming. Males and females maintained their water balance by eating moisture-rich fruits. Soon the families dispersed in order to reduce impact on resources. The baboons dug and drank from nearby pits, kept to the shade, and remained subdued during the heat, conserving their energy while avoiding needless risks. But as drought wore on, as those pits caked into mud and then dust, the primate crossed some invisible line.
Casual cooperation broke down. Large males commandeered remaining puddles and jealously guarded the slow seepage. Others began screaming at each other, slapping, hitting, clawing hair, and biting ears in the unrelenting heat. Inevitably, competition turned deadly. In 120-degree heat, thirty weak baboons collapsed from deprivation. Dominant males emerged with bloody hands and teeth, obtaining moisture from the eyes and liquid parts of former colleagues. In order to survive the primates had begun eating, and drinking, their own.
While humans had evolved far above such simian savagery, basic survival instincts remained locked within, waiting until the rains failed several years in a row. Whereupon protracted drought turned peaceful neighbors into hostile rivals who snarling fiercely at one another. In many dry regions of the world, previously congenial rural farmers, herders and fishers had all, at some indefinable point, picked up their shovels and machetes and hacked each other over competing claims to vanishing creeks.
Like baboons at that shrinking water hole, Homo sapiens fought over water in mostly isolated sporadic violence, as appeared to have occurred in America’s first thirst and hunger-wracked colony at Jamestown. In the name of securing resources, various stressed and thirsty individuals—albeit predominantly males—might commit assault, battery, rape, and murder if they could get away with it. But as society grew populous and complex, the nature of violence changed; hierarchies established loyal units for team defense and organized aggression.
These units typically overlapped, like concentric circles. Americans bound allegiance to neighbor, city, state, country, NATO alliances and the U.N. At each level we united with others in a mutually beneficial relationship to form a tight-knit solidarity, securing and forcibly defending our shared interests in stability with security guards, sheriffs, SWAT teams, militias, armies, divisions and peacekeeping forces, respectively. But as populations grew and drought bore down, thirst turned people against one another other.
The shortage of water resources threatened to undermine the bonds of what had been socially cohesive units. In southern Africa, water-rationed suburban families snitched on local neighbors to utilities who fought agricultural interests for a greater share of reservoirs. In America, cities and states gazed covetously at flowing water, and mobilized quickly and aggressively to seize neighboring rivers as their own. Around the arid world, competing jurisdictions divided the loyalty of police and militias and armies, as states seized watery borders, threatening war over the streams they shared.
Sun Tzu knew the value of thirst. As water continues to grow increasingly volatile and unreliable, so do the people and armies who depend on it.