express a similar confidence when it comes to armed conflict in the world as a whole.
I am sometimes asked, “How do you know there won’t be a war tomorrow (or a genocide, or an act of terrorism) that will refute your whole thesis?” The question misses the point of this book. The point is not that we have entered an Age of Aquarius in which every last earthling has been pacified forever. It is that substantial reductions in violence have taken place, and it is important to understand them. Declines in violence are caused by political, economic, and ideological conditions that take hold in particular cultures at particular times. If the conditions reverse, violence could go right back up.
Also, the world contains a lot of people. The statistics of power-law distributions and the events of the past two centuries agree in telling us that a small number of perpetrators can cause a great deal of damage. If somewhere among the world’s six billion people there is a zealot who gets his hands on a stray nuclear bomb, he could single-handedly send the statistics through the roof. But even if he did, we would still need an explanation of why homicide rates fell a hundredfold, why slave markets and debtors’ prisons have vanished, and why the Soviets and Americans did not go to war over Cuba, to say nothing of Canada and Spain over flatfish.
The goal of this book is to explain the facts of the past and present, not to augur the hypotheticals of the future. Still, you might ask, isn’t it the essence of science to make falsifiable predictions? Shouldn’t any claim to understanding the past be evaluated by its ability to extrapolate into the future? Oh, all right. I predict that the chance that a major episode of violence will break out in the next decade—a conflict with 100,000 deaths in a year, or a million deaths overall—is 9.7 percent. How did I come up with that number? Well, it’s small enough to capture the intuition “probably not,” but not so small that if such an event did occur I would be shown to be flat-out wrong. My point, of course, is that the concept of scientific prediction is meaningless when it comes to a single event—in this case, the eruption of mass violence in the next decade. It would be another thing if we could watch many worlds unfold and tot up the number in which an event happened or did not, but this is the only world we’ve got.
The truth is, I don’t know what will happen across the entire world in the coming decades, and neither does anyone else. Not everyone, though, shares my reticence. A Web search for the text string “the coming war” returns two million hits, with completions like “with Islam,” “with Iran,” “with China,” “with Russia,” “in Pakistan,” “between Iran and Israel,” “between India and Pakistan,” “against Saudi Arabia,” “on Venezuela,” “in America,” “within the West,” “for Earth’s resources,” “over climate,” “for water,” and “with Japan” (the last dating from 1991, which you would think would make everyone a bit more humble about this kind of thing). Books with titles like The Clash of Civilizations, World on Fire, World War IV, and (my favorite) We Are Doomed boast a similar confidence.
Who knows? Maybe they’re right. My aim in the rest of this chapter is to point out that maybe they’re wrong. This isn’t the first time we’ve been warned of certain ruin. The experts have predicted civilization-ending aerial gas attacks, global thermonuclear war, a Soviet invasion of Western Europe, a Chinese razing of half of humanity, nuclear powers by the dozen, a revanchist Germany, a rising sun in Japan, cities overrun by teenage superpredators, a world war fought over diminishing oil, nuclear war between India and Pakistan, and weekly 9/11-scale attacks.240 In this section I’ll look at four threats toto the New Peace—a civilizational clash with Islam, nuclear terrorism, a nuclear Iran, and climate change—and for each one make the case for “maybe, but maybe not.”
The Muslim world, to all appearances, is sitting out the decline of violence. More than two decades of headlines have shocked Westerners with acts of barbarity in the name of Islam. Among them are the 1989 clerical death threat against Salman Rushdie for portraying Muhammad in a novel, the 2002 sentencing of an unmarried pregnant woman in Nigeria to execution by stoning, the fatal stabbing in 2004 of Dutch filmmaker Theo van Gogh for producing Ayaan