Blood and Leviathan

A Stanford historian thinks war is the engine that drives civilization. Is he right?


Detail of Trajan's Column, Rome
Ken Welsh / Alamy

War! What Is It Good For? Conflict and the Progress of Civilization from Primates to Robots, by Ian Morris, Farrar, Straus and Giroux, 495 pages, $30

Is war good for anything? In the long run, the Stanford historian Ian Morris argues, it's good for almost everything. In War! What Is It Good For?, Morris makes the case that war has played an essential role in mankind's development and in the growth of human well-being. The book endorses not just strong government but imperialism; as applied to recent history, this translates into strong support for the historic role of the British Empire and the current global policies of the United States.

Morris isn't one to shy away from big, sweeping theses. In Why the West Rules—For Now (2010), he took on the much-studied subject of why modernity first appeared in northwestern Europe and has been dominated by that part of the world and its offshoots. Its sequel, The Measure of Civilization (2013), proposed a metric for assessing how "developed" any particular historical culture was.

His new book's argument is rich and subtle. That is not to say it is convincing. It has a number of crucial ambiguities and at least one central thesis that is very controversial and, like all good theses in history, subject to empirical disproof. The story also has an important missing element, one that makes sense of things the author otherwise has difficulty fitting into his argument. Adding that missing element—the way that resource constraints limited human options until innovation took off in the 17th century—gives us a different, more accurate picture.

The book's thesis is Hobbesian, as Morris explicitly lays out. Human beings, he writes, are naturally territorial and aggressive; Lord of the Flies is a better portrait of our nature than Coming of Age in Samoa. Consequently, the default setting for human society is one with little or no large-scale, organized conflict but lots of persistent small-scale violence, such as fights, brawls, and raids.

The result is a very high rate of violent death, amounting to as much as 20 percent of all deaths in hunter-gatherer societies. (This claim is disputed, as Morris notes, but he is correct that the evidence supports this reading of the Stone Age past.) In this, human beings are like one of our two closest biological relatives (chimpanzees) but unlike the other (bonobos). The amount of chronic interpersonal violence means that complex social institutions and trade do not develop—not among chimps, and not among humans for most of our history as a species.

Unlike chimpanzees, Morris continues, human beings have the ability to evolve socially as well as biologically. Our ancestors invented agriculture in those parts of the world (the "lucky latitudes") whose flora and fauna were particularly suited to domestication. This led to a rise in human numbers, to more division of labor, and to greater pressure on resources. The initial response to that pressure was migration into empty lands. Meanwhile, high levels of violent death remained the norm. Eventually, Morris argues, population pressure changed the incentives and led to a major innovation: war.

The obvious immediate result of war is a sharp rise in the number of violent deaths as the scale of killing increases. But war also creates bandit groups that control the means of violence and use it to organize people. The incentives facing these predatory groups initially encourage them to plunder and kill others, but soon it becomes clear that the longer-term incentive is to conquer them (often brutally) and incorporate them into an expanded social unit. Once this is done, the roving bandits become stationary bandits: a polity's ruling class.

This Leviathan then reduces the level of chronic violence in society, Morris writes, by punishing violent conduct and getting the predatory groups to change their behavior, so they become cultured gentlemen rather than coarse warriors. All of this leads to a rise in population and a marked growth in wealth and trade and the division of labor. The consequences include technological development, the emergence of cities, and higher levels of comfort and consumption. Although the number of people killed in the wars that create the Leviathan is high, the rates of death per capita decline, because of both the change in people's behavior and the resulting growth in numbers.

Morris thinks that war is essential for this good result and that it is the primary motor, with the other social phenomena consequences. The Leviathans created by war (such as the Roman Empire, which stands as a proxy for Leviathan states in general in the early part of the book) tend to expand their territory until they reach a point (determined by the interplay of geography, technology, and military organization) where the costs of expansion are greater than the benefits. In the modern world, this is the entire planet, and so we see the development of a global hegemon, initially the British Empire and more recently the United States, that while not directly controlling the entire world provides a legal order for it as a "globocop."

Clearly this is a direct challenge to many cherished libertarian ideals and ideas. If Morris' argument is true, order is not spontaneous but something that can exist at a tolerable level only after powerful states have been created by war; empires are in general a force for good; and human flourishing, innovation, and prosperity depend on a strong, active government. In terms of current policy disputes, it means that the United States should enhance its global role rather than pulling back.

Yet the argument's clarity lays bare several ambiguities that in turn reveal its weaknesses. The major problem that Morris faces is explaining what was going on from roughly the 2nd century A.D. through the 15th century. Up until that point, his long-term story was one of wars leading to ever larger and more settled empires, with a corresponding growth in human development and decline in interpersonal violence. (There was in fact a major intermission of several hundred years at the end of the Bronze Age, but he glosses over this.) In the Middle Ages, this long-term trend stalled. There were still empires and powerful states, but these regularly collapsed completely or, more often, saw a decline in strong central power and the growth of a decentralized, usually feudal social order. The new long-term trend was for the size of effective political units to shrink.

Morris sees all of this in dark terms. He argues that there was a revival of personal violence (although not a complete return to the pre-state level), and he uses the term "feudal anarchy" to describe the society of medieval Europe, as though England during the reign of Stephen were the typical case.

We may leave aside the question of whether this dark picture is an accurate one. As Morris says, this is an empirical question, and more research must be done before it is settled. His difficulty is how to address it in a model where war is the ultimate explanatory factor. His answer is to say there are actually two kinds of war, "productive" and "unproductive," with the second kind dominant between the 2nd and 15th centuries.

It is not clear how we are to distinguish between these two kinds of war and what the criterion is for making this distinction. Much of the time, it seems simply to be about result: Productive wars result in stable and effective states while unproductive wars undermine or destroy them. But this threatens the entire thesis, because it makes the beneficial effects of war either purely contingent or dependent on some other variable factor, which would mean that war would lose its position as the sole root enabler of social development.

His solution is to imply that the distinction rests on the form of military organization and technology. Morris comes very close to saying that cavalry-based warfare is intrinsically unproductive while infantry-based and naval warfare are productive. The horsemen of the steppes, he claims, were the destructive force that repeatedly brought about episodes of unproductive war and so stalled the process described in the first part of the book.

This is highly problematic, to put it mildly. In terms of Morris' own argument, it is never made clear exactly why steppe nomads were not subject to the same incentives as other roving bandits and did not themselves create stable polities after they conquered large areas. The argument appears to be that they would themselves be overthrown in turn by further waves of nomads. Yet settled civilizations did repeatedly defeat nomads and showed they could exploit the nomads' great weakness, their fragmented and tribal social order.

There are also simple concrete objections to this story. For it to work it has to apply right across Eurasia's "lucky latitudes" for the whole of this period, and it simply doesn't. It applies in the Middle East and India, but in Europe there was no major nomad incursion following the defeat of the Magyars at the Lechfeld in 955 until the Mongols briefly invaded eastern and central Europe in 1240. The following year they withdrew and never returned. The Vikings (who do not fit this narrative anyway) also stopped being mobile bandits in the 10th century and followed the pattern of settling down and becoming stationary bandits. Given this, Morris' model would lead you to expect medieval Europe to see the growth of a single large empire. In fact the tendency was toward more fragmentation, not least in Germany and Italy.

It also does not work at the other end of Eurasia. In China, the period saw two classic Leviathans of the earlier kind, the Tang and Song dynasties. Morris claims that these were "zombie" empires that in some sense did not compare to the earlier Han and Roman examples. Yet given the length of time they lasted and the degree of social development they saw (particularly in the case of the Song), this simply does not make sense. In Japan a similar process of weakening and ultimate collapse of central power took place under the Ashikaga Shogunate after the 14th century, but Japan as an archipelago was not substantially affected by events on the Eurasian landmass. There has to be some other factor that explains what was happening, even within Morris' own narrative.

The second ambiguity casts more light on this problem. Morris gives innovation and the human capacity for it a central part in his account. He also explicitly argues that the kinds of innovation that lead to economic growth and social development can happen only after productive war has created a Leviathan. But it is our capacity for innovation that led to the development of war itself. Clearly, innovation is an independent variable and not a simple dependent one. The story of the interplay between governance and war on the one hand, and innovation, exchange, and voluntary cooperation on the other, is complex, with causal arrows running in both directions. Both domains of human conduct are autonomous, and neither is only a consequence of the other.

Moreover, it is obviously not the case that Leviathans are the only kind of political order that emerges from this interplay between conflict and innovation. Repeatedly we see an alternative: a self-sustaining network (sometimes an actual federation) of small political units, particularly city-states. The largest-scale instance of this is in Southeast Asia from the 7th to 15th centuries, but the ancient world and medieval Europe also saw many examples. The evidence of the Hellenistic era between Alexander and Actium shows that this kind of political order is actually associated with high levels of innovation. Morris would argue that it also saw an unacceptable level of chronic small-scale warfare. But how destructive that actually was is an empirical question where the jury is still out.

This brings us to the book's third ambiguity, which becomes apparent in its account of the 500 years since the medieval period ended. For Morris, humanity escaped the trap of the Middle Ages with the military revolution of the 15th through the 17th centuries. In most of the world, this led to a rerun of the ancient Mediterranean or Warring States China, with one state establishing a large empire (Russia, the Ottomans, Safavid Iran, Ming and then Qing China, Mughal India). But in Europe, for largely contingent reasons, no hegemon emerged. Instead of an empire, we got the Westphalian system of sovereign territorial states.

Morris misses a trick here because of his focus on war and relegation of innovation. He concentrates on what he calls the Five Hundred Years' War, in which Europeans (who had pushed the military revolution further because of internal competition) expanded their political control to the rest of the planet and created a world order dominated by Britain. But of course it was not only in warfare that Europeans became more innovative.

Seeing innovation as an independent variable makes events more clear. States' ruling elites have an interest in trade and innovation, because they create wealth that can be taxed. But trade and innovation are also threats. By giving non-military and non-ecclesiastical groups greater economic independence—and by simply enlarging the range of options open to ordinary people—they undermine elites' control.

Furthermore, innovation is risky when resources are finite, because most innovations fail. Consequently, most elites act to check innovation or even reverse it. Empires and large states may give a boost to economic life by providing public goods on a stable basis over a large area, but in the long run they cause stasis by checking innovation.

In Europe from the 17th century onwards, the failure of a hegemon to emerge and the interstate competition that resulted changed the incentives facing rulers. They now had more reasons to encourage innovation and growth, and increasingly they did so. The social status and rewards to innovators and people engaged in exchange rose sharply. The result was the sustained, intensive growth that is a central feature of modernity. For Morris this was a result of the renewal of productive war brought about by the military revolution, but if that were so then the benefits should have been even greater had Europe become united under the Habsburgs or Bourbons—and they should have been greater still in China or the Middle East. They were not.

The most interesting part of the book may be the final chapter, which looks forward to the next 50 years. For Morris, this is a time of great possibility but also great risk. He worries that in the absence of an effective globocop, war will once again become unproductive and we will see a repeat of the middle years of the 20th century (but with far more destructive weapons) or, even worse from his perspective, a relapse into "feudal anarchy."

Morris is optimistic, though. He thinks we still need war and an effective globocop, but only for a little while. Innovation, he argues, promises to so completely transform the human condition that war will finally become redundant. So we need Leviathan just long enough to allow something (the Singularity?) to finally transform the incentives we face so that violence no longer makes sense.

There are two things to say to this. The first is that the evidence suggests a global hegemon is more likely to strangle the innovation we need. It was competition between the states in Europe that led to the sudden upsurge in innovation, as had arguably been the case earlier in the Hellenic world. We should aim for a more decentralized world, perhaps of city-regions, not a planet with a single globocop.

Second, the reason for Morris' optimism comes from his earlier work on measuring social development. He showed just how much more developed the modern world is than any previous civilization, and simply extrapolating that development leads to the conclusion that we are indeed on the verge of a fundamental transformation. The other side of that, however, is that all of the previous "peaks" in human development were not merely much lower than where we are now; they were all at about the same level as each other. Why was this?

The answer is the missing factor in Morris' story, the persistence of Malthusian constraints. After the development of agriculture, our ancestors lived in a Malthusian world. Periodically, civilizations would get one-off gains from one source or another, leading to growth, innovation, and also wars, which led to the formation of large, stable states. Eventually, the Malthusian limits would be hit, and at that point a process of breakdown would begin.

In the long period from roughly A.D. 200 to 1450, the civilizations of settled Eurasia kept hitting Malthusian limits. It is this rather than horsemen that explains why the process that had gone on in the ancient world was not sustained as long as it had been then. After the 15th century, the New World gave Eurasia another productivity-increasing natural windfall, and the process resumed.

Since about 1720, we seem to have escaped from the Malthusian girdle. If we have, then the reason is not simply, much less only, war. It is because of sustained innovation. Productive wars in Morris' sense played a critical part, but only in Europe and probably for highly contingent reasons. It may be that Malthusian constraints are starting to reappear. That and the continuing threat of war is why it really may well be "the Singularity or bust."

The question Morris poses is, "Do we still need the war system to do this?" The answer is not as clear as he supposes. His own evidence shows that it is actually innovation that is crucial, and that wars and the states they engender are more likely to hinder or even stop the process. Rather than Leviathan, we need a different kind of political order, one that is more open, more resilient, and not driven by power.