War! What Is It Good For? Conflict and the Progress of Civilization From Primates to Robots BY IAN MORRIS. Farrar, Straus and Giroux, 2014, 512 pp. $30.00.

The philosopher Alfred North Whitehead once remarked that the history of European philosophy consists of a series of footnotes to Plato. For Ian Morris, world history may be understood as a series of footnotes to Thomas Hobbes. In Hobbes’ philosophy, order takes pride of place among all social conditions. Without it, human existence becomes, in his oft-quoted phrase, “nasty, brutish, and short.” Order, he wrote, comes about through the creation of a powerful government, which he termed “Leviathan,” after the Old Testament sea monster.

According to Morris’ sweeping history of conflict from prehistoric times to the present, order comes from governments strong enough to protect the people living under their jurisdiction, just as Hobbes said it did. Such governments, in turn, emerge from war. The answer to the question posed by the title of Morris’ book is that war is good for producing safety -- in other words, that war is good for peace. To be sure, not all wars are, as Morris puts it, “productive”; those that weaken or break up Leviathans earn the label “counterproductive,” since they make people more vulnerable. In his telling, human history has seen long periods of both kinds. In making his case, Morris provides a useful overview of military history since the beginning of organized warfare, although his account runs into difficulties as it approaches the present.

A HISTORY OF VIOLENCE

Morris’ account begins 10,000 years ago, in the Stone Age, when the planet’s several million human inhabitants lived in small, warring bands of hunter-gatherers. In this unhappy era, by admittedly very rough estimates, between ten and 20 percent of all people could expect to die violently at the hands of others. Over the next five millennia, conditions improved thanks to the first great change in the history of the human species: the advent of agriculture and the development of large, settled communities based on farming. The most powerful of these communities expanded and incorporated lesser ones, making use of a variety of military innovations, including bronze weapons, fortifications, and chariots. Ultimately, large empires came into being, including the Mauryan in South Asia, the Han in China, and the Roman Empire around the Mediterranean.

These ancient Leviathans made life safer. Powerful governments could and did protect the people living in their territories, discouraging murder and deterring war. The rate of fatalities from violence dropped sharply, by Morris’ calculation to somewhere between two and five percent of all deaths. The Leviathans also made their inhabitants richer. To explain how this occurred, Morris draws on the economist Mancur Olson’s concept of the “stationary bandit.” Whereas a “roving bandit” raids settlements, steals as much as he can get, and then moves on, rulers of large agricultural communities, while no less greedy, stay in place. They therefore have an interest in promoting the prosperity of those they rule -- that way, there is more to steal. And since prosperity requires order, they impose it. The gains of the roving bandit are called “loot.” Stationary bandits call what they extract “taxes,” and the more peaceful their domains, the more revenue they can collect.

The tranquility fostered by the ancient empires and the stationary bandits who ruled them did not last. One particular military innovation was responsible: the use of the horse. Nomadic bands mastered mounted combat and were thus able to win counterproductive wars. These new military powers acted as roving bandits: they raided, looted, weakened, and ultimately brought down the Leviathans. This is how the mighty Roman Empire declined and fell. In Europe, the centuries afterward are sometimes called the Dark Ages. Morris thinks the term is appropriate for other parts of the world as well. As the counterproductive wars destroyed the ancient empires, the world became a disorderly place during the first 14 centuries of the Common Era. The rate of deaths from violence rose again, to between five and ten percent.

Beginning around the time of the Renaissance, however, disorder gave way to a 500-year period of consolidation. Once again, a major military innovation -- gunpowder -- initiated the shift. Leaders regained their ability to assemble large political units, this time by using ever more powerful guns and cannon. Within these units, the rate of violent death declined. In the latter part of this era, beginning around 1760, the second great transformation in human history occurred: the Industrial Revolution. The Europeans put the machines it produced to military as well as civilian use, enabling them to conquer much of the rest of the world in the nineteenth century. As in the ancient empires, within the great European empires of modern times -- some of them, notably the British one, stretching around the globe -- life became safer than ever before.

The nineteenth century also saw the emergence of what Morris calls a “globocop,” a power with responsibility for order on a global scale. The United Kingdom played this role until World War II, after which the United States took its place. Over the course of two millennia of productive warfare, the planet had moved from Pax Romana to Pax Brittanica to Pax Americana. Human existence became increasingly safe. The worldwide rate of violent death in the twenty-first century has reached an all-time low, falling below one percent.

THE FUTURE OF WAR

Over a time span as long as the one Morris covers, it is possible to find evidence for almost any pattern, but the one he puts at the center of his book surely does have historical significance. Powerful states have indeed protected their inhabitants (while also often oppressing them), and the mechanism for the formation of such states has ordinarily been war. “War is the father of all things,” the ancient Greek philosopher Heraclitus observed, so it should not be surprising that one of its offspring has been peace.

The pattern Morris identifies, however, seems to fit the distant past better than it does recent history, let alone the future. In the twentieth century, the trend toward the consolidation of states went into reverse, with modern empires dissolving and leaving behind smaller political units, but without life becoming nastier, more brutish, or shorter. Indeed, over the last hundred years, the chief determinant of a given state’s rate of violence has been its competence, not its size. The Scandinavian countries, anything but Leviathans by contemporary standards, have become the safest places in the world. In fact, small nation-states have proved less prone to violence than large multinational empires, by virtue of the greater legitimacy that homogeneous units enjoy among their inhabitants. People are generally more willing to be governed by those with whom they share an ethnicity, a religion, or a language than by those they regard as foreigners, and they are prepared to fight for the political system they prefer.

In the nineteenth century, moreover, the British globocop did little to make life safer outside its imperial borders. Far from policing Europe -- the part of the planet that would prove susceptible to bouts of deadly violence in the twentieth century -- the British remained aloof from it. Peace and order on the continent depended on a balance of power among its major states, not on British exertions. The United Kingdom did use its navy to provide a secure framework for an increasingly global economy. In this way, British military might and political influence did a great deal to raise standards of living all over the world, but not much, outside the British Empire, to reduce the chances of dying violently.

To cite one more awkward application of Morris’ pattern to the recent past, World War I and World War II seem to qualify as “productive” by his definition of the term because they paved the way for the advent of the American globocop. Their combined death toll of something on the order of 100 million people does seem, however, to be an excessive price to pay simply to replace one hegemon with another.

Finally, whatever long-term benefits war may have provided in the past, it is difficult to see how, outside a few chaotic, conflict-ridden places, it can be good for peace in the future. Hobbes and the pattern of productive wars Morris identifies do have some relevance for the people of the Democratic Republic of the Congo, Iraq, and Syria, for example, but in the rest of the world they seem largely irrelevant. The possibility of large-scale violence does persist. Advances in military technology over the last century have given governments the capacity to send rates of violent death skyrocketing should they decide to avail themselves of the most powerful weapons at their disposal.

Morris perceives the greatest threat in the future as coming from a repetition of events in the early twentieth century, when Germany challenged the United Kingdom and plunged the world into two terrible conflicts. Today, with the United States occupying the position the British held a hundred years ago, it is China that poses the threat to the reigning globocop. “If the forty years between the 2010s and the 2050s do unfold like the forty between the 1870s and the 1910s,” he writes, drawing a parallel between the United Kingdom then and the United States now, “they will be the most dangerous in history.” The reason is that should China mount a challenge to the United States that leads to a war on the scale of the two that Germany’s ambitions triggered, the two sides could employ the nuclear weapons they possess. This would ensure that whatever adjectives its survivors apply to such a conflict, “productive” would not be one of them.

For Morris, the hope for avoiding such a twenty-first-century cataclysm rests on technology. Computing in particular, he suggests, may progress so rapidly in the years to come as to transform the human species, and the resulting “transhuman” or “posthuman” creatures may be able to transcend violence altogether. Here Morris relies on the ideas of several imaginative futurists. Their visions have the ring of science fiction, and the predictions of science fiction have sometimes proved accurate. Sometimes, however, they haven’t, and it seems incautious, to put it mildly, to rely on the realization of such visions to prevent World War III.

There are other possibilities. For one thing, ideas about war have changed. Once seen as an inevitable feature of human existence, this ancient practice is increasingly regarded as unacceptable, outdated, and avoidable. The enormous destruction modern weapons can wreak imparts a measure of prudence to foreign policy that was rarely, if ever, present before the middle of the twentieth century.

Moreover, the great conflicts of the first half of that century stemmed in no small part from ideology, a feature of social and political life unknown before the French Revolution and therefore not a part of most of the history that Morris covers. Germany’s commitment to fascist ideas and the Soviet Union’s commitment to communist ones made the world a much bloodier place than it would otherwise have been. Germany, at least, became far more peaceful in the wake of World War II, as did the other great imperial aggressor of that conflict, Japan, in part because the two countries adopted the political ideas and the political system of one of their conquerors, the United States. Democracy helped engender peace. Indeed, the tendency of democracies to avoid war with one another is now well established, and it offers the hope of preventing a massive counterproductive war in the future. If China should become democratic, the prospects for avoiding a rerun of the Anglo-German rivalry, but this time with twenty-first-century armaments, would surely improve.

Democracy is not guaranteed to come to China in the near future, or indeed ever. But a democratic China does seem more plausible, and thus a better bet for keeping the peace, than a computer-driven transformation of the human species. To be sure, the creation and maintenance of order, safety, and peace through the spread of democracy is not a theme of Leviathan. But while Hobbes was a powerful, seminal thinker, there are, in our day, more things between heaven and earth than were dreamt of in his philosophy.