theory of the Vietnam War is an example of resource determinism, the idea that people inevitably fight over finite resources like land, water, minerals, and strategic terrain. One version holds that conflict arises from an unequal allocation of resources, and that peace will come when they are distributed more equitably. Another feeds into “realist” theories that see conflict over land and resources as a permanent feature of international relations, and peace as the outcome of a balance of power in which each side is deterred from encroaching on the other’s sphere of influence.
While contests over resources are a vital dynamic in history, they offer little insight into grand trends in violence. The most destructive eruptions of the past half millennium were fueled not by resources but by ideologies, such as religion, revolution, nationalism, fascism, and communism (chapter 5). Though no one can prove that each of these cataclysms wasn’t really about tungsten or some other ulterior resource, any effort to show that they are is bound to look like a nutball conspiracy theory. As for the balance of power, the upending of the pans after the Soviet Union collapsed and the Germanys were unified did not send the world into a mad scramble. Rather, it had no discernible effect on the Long Peace among developed countries, and it presaged a New Peace among developing ones. Nor did either of these pleasant surprises originate in the discovery or redistribution of resources. In fact, resources in the developing world often turn out to be a curse rather than a blessing. Countries rich in oil and minerals, despite having a larger pie to divide among their citizens, are among those with the most violence (chapter 6).
The looseness of the connection between resource control and violence should also come as no surprise. Evolutionary psychologists tell us that no matter how rich or poor men are, they can always fight over women, status, and dominance. Economists tell us that wealth originates not from land with stuff in it but from the mobilization of ingenuity, effort, and cooperation to turn that stuff into usable products. When people divide the labor and exchange its fruits, wealth can grow and everyone wins. That means that resource competition is not a constant of nature but is endogenous to the web of societal forces that includes violence. Depending on their infrastructure and mindset, people in different times and places can choose to engage in positive-sum exchanges of finished products or in zero-sum contests over raw materials—indeed, negative-sum contests, because the costs of war have to be subtracted from the value of the plundered materials. The United States could invade Canada to seize its shipping lane to the Great Lakes or its precious deposits of nickel, but what would be the point, when it already enjoys their benefits through trade?
Affluence. Over the millennia, the world has become more prosperous, and it has also become less violent. Do societies become more peaceful as they get richer? Perhaps the daily pains and frustrations of poverty make people more ornery and give them more to fight over, and the bounty of an affluent society gives them more reasons to value their lives, and by extension, the lives of others.
Nonetheless tight correlations between affluence and nonviolence are hard to find, and some correlations go the other way. Among pre-state peoples, it is often the sedentary tribes living in temperate regions flush with fish and game, such as the Pacific Northwest, that had slaves, castes, and a warrior culture, while the materially modest San and Semai are at the peaceable end of the distribution (chapter 2). And it was the glorious ancient empires that had slaves, crucifixions, gladiators, ruthless conquest, and human sacrifice (chapter 1).
The ideas behind democracy and other humanitarian reforms blossomed in the 18th century, but upsurges in material well-being came considerably later (chapter 4). Wealth in the West began to surge only with the Industrial Revolution of the 19th century, and health and longevity took off with the public health revolution at the end of the 19th. Smaller-scale fluctuations in prosperity also appear to be out of sync with a concern for human rights. Though it has been suggested that lynchings in the American South went up when cotton prices went down, the overwhelming historical trend was an exponential decay of lynchings in the first half of the 20th century, without a deflection in either the Roaring Twenties or the Great Depression (chapter 7). As far as we can tell, the Rights Revolutions