War and Peace and War: The Rise and Fall of Empires

by Peter Turchin

Different groups have different degrees of cooperation among their members, and therefore different degrees of cohesiveness and solidarity. Following the fourteenth-century Arab thinker Ibn Khaldun, I call this property of groups asabiya. Asabiya refers to the capacity of a social group for concerted collective action. Asabiya is a dynamic quantity; it can increase or decrease with time. Like many theoretical constructs, such as force in Newtonian physics, the capacity for collective action cannot be observed directly, but it can be measured from observable consequences.

In this book, therefore, I discuss three central concepts: the metaethnic frontier theory, which explains asabiya cycles; the demographic-structural theory, which explains secular cycles; and the social-psychology theory, which explains the fathers-and-sons cycles. These theories comprise part of a new science of historical dynamics, or as I prefer to call it cliodynamics (from Clio, “muse of history,” and dynamics, “the study of processes that change with time”). Cliodynamics borrows heavily from two disciplines in the natural sciences. The focus on groups rather than individuals is akin to the approach of statistical mechanics, which integrates over motions of myriads of particles to predict such properties of the ensemble as temperature or pressure. However, the study and prediction of human groups is a much more challenging task because people vary (among other things, for example, in power and ethnic identity). Humans also possess free will. I discuss the implications of these complicating factors for the study of human societies in Chapter 12.

Returning to the main question of the book, we have hit upon a powerful macrohistorical generalization. People originating on fault-line frontiers become characterized by cooperation and high capacity for collective action, which in turn allows them to build large and powerful territorial states. In other words, we have the beginnings of the theory explaining how imperial nations rise to power. But could the association between fault lines and mighty states arising from them be a fluke? After all, so far we have only three examples. The next order of business is to find out whether the postulated relation holds generally. To do that, we travel to the banks of the Rhine and Danube during the first few centuries A.D.

The concept of a “civilizational fault line” was popularized by the political scientist Samuel P. Huntington in his 1996 book The Clash of Civilizations. Huntington argued that after the collapse of the Soviet Union, different countries began aligning themselves not along the ideological divide between communism and liberalism, but reverted to older sources of large-scale identity, based on belonging to various world civilizations. Huntington’s thesis provoked a storm of controversy, and I myself could quibble with many of the points that he raised. Nevertheless, the decade since he wrote the book has amply demonstrated that his main insight is correct. The events of 9/11 and the wars that the United States subsequently waged in Afghanistan and Iraq are precisely the kind of a “fault-line war” that he predicted.

The religious controversies centered on the two natures of Christ. The Nestorians argued that Christ had two separate natures, one human and one divine, in the same person, but not commingled. Monophysites, by contrast, claimed that Christ’s two natures were fully combined into one. Finally, the Chalcedonians maintained a middle-of-the road position that Christ was completely human and completely divine, one and the same Christ having two natures without confusion or change, division, or separation. This probably sounds like complete gibberish to many readers, and it does to me. It is hard to believe that anyone other than a handful of theologians steeped in their arcane lore could make any sense of this distinction. How could a soldier, a peasant, or a boot maker get passionate about this question? Yet, when in 457 a pro-Chalcedonian bishop was imposed on Monophysite Alexandria, the Alexandrians rioted, lynched him, and installed a Monophysite in his place.

Personal misfortune continued to dog him. In the winter of 1384, Ibn Khaldun’s wife and five daughters, sailing from Tunis to join him in Cairo, were lost in a shipwreck. But Ibn Khaldun was not a man to resign himself to despair.

The concept of collective solidarity, or asabiya in Arabic, was Ibn Khaldun’s most important contribution to our understanding of human history. The theory is described in his monumental The Muqaddimah: An Introduction to History. Asabiya of a group is the ability of its members to stick together, to cooperate; it allows a group to protect itself against the enemies, and to impose its will on others. A group with high asabiya will generally win when pitched against a group of lesser asabiya. Moreover, “royal authority and general dynastic power are attained only through a group and asabiya. This is because aggressive and defensive strength is obtained only through ... mutual affection and willingness to fight and die for each other.” In other words, a state can be organized only around a core group with high asabiya. By acting in a solidary fashion, the members of the core group impose their collective will on other constituents of the state and thus prevent the state from falling apart.

The civilization zone is divided into states and empires, which are, in any case, normally quite good at defending themselves against nonstate societies. For one thing, the civilization supports much greater population densities than the desert, so the civilized armies tend to be larger than the “barbarian” ones. Civilizations also have technological advantages, such as fortifications, catapults, better arms, and armor. As long as the state keeps its internal cohesion, it is capable of defending itself against the nomads. (There are exceptions—nobody could stand against the Mongols of Chinggis Khan.) When the state loses its unity and falls into civil strife, however, it immediately becomes easy prey for Bedouins. Ibn Khaldun noticed that political dynamics in the Maghreb tend to move in cycles. When a state in the civilization zone falls into internal strife, it becomes vulnerable to conquest from the desert. Sooner or later, a coalition of Bedouin tribes is organized around one group with a particularly high asabiya. When this coalition conquers the civilization zone, it founds a new state there. The leading group establishes the ruling dynasty, while other Bedouins become the ruling class—the new aristocracy.

The members of the conquering generation and even their children preserve their desert ways. They keep their military skills honed, and, most importantly, their group solidarity high. As generations succeed generations, however, the conditions of the civilized life begin to erode the high asabiya of the former Bedouins. Generally speaking, by the fourth generation the descendants of the founders become indistinguishable from their city-dweller subjects. At this point, the dynasty goes into a permanent decline. It can persist in the “degenerate” state for a few more generations, but sooner or later another Bedouin coalition arises in the desert, and the cycle repeats itself. The members of the degenerated dynasty are dispossessed of their wealth, some killed, and others driven into exile.

THE WILLINGNESS TO SACRIFICE LIFE in the name of the faith has been one of the enduring strands in the history of Islam. One of the best-known examples is the Hashishim sect, which existed from the eighth century until its suppression by the Mongols. The name Hashishim (“Assassins”), actually was what their enemies called them, because they allegedly used drugs to indoctrinate sect members. Their own name for themselves was fedayeen, which in Arabic means “one who is ready to sacrifice life for the cause.” The Hashishim were opposed to the Abbasid caliphs, whom they thought to be impious usurpers. They conducted a campaign of assassination directed mainly against the Sunni Muslim rulers (but they also murdered at least one crusader king in Jerusalem). Because the Hashishim disdained the use of poison or long-range weapons, and relied on the dagger, assassination attempts usually ended in the death of the assassin; these were suicide missions. The parallels with the suicide bombings happening in the Middle East today are palpable. Earlier I cited the words of Khalid ibn al-Walid, “I lead those who love death as you love life.” Fourteen centuries later, perpetrators of terrorist acts in Palestine, Madrid, Moscow, and Baghdad have used precisely the same words.

Here then a powerful general principle of world history is uncovered: A close connection exists between fault-line frontiers and new, expansionist states. However, what about the specific mechanism that I proposed to account for this empirical generalization—the role of frontier in nurturing high degree of cooperation, or asabiya, to use Ibn Khaldun’s term? This explanation runs counter to the “received wisdom” of social science in the twentieth century, when the main current was to downplay the importance of cooperation and altruism while putting on the pedestal self-interested, “rational” motives of behavior. Influential thinkers, such as Carrol Quigley in his The Evolution of Civilizations: An Introduction to Historical Analysis, or Joseph Tainter in The Collapse of Complex Societies, contemptuously dismissed theories, such as Ibn Khaldun’s, as “the softening of the fiber” or “mystical” explanations. The majority of social scientists perceived cooperation and collective solidarity as somehow “soft” and unscientific, while (and this was particularly true for the economists) extolling the virtues of the “rational-choice theory” that explained the collective behaviors of human masses by assuming that all people behave in a purely self-interested manner.

During the twentieth century, the ideas of Mandeville, Smith, and many others have been developed and systematized into what is now known as “the theory of rational choice.” The core of the theory is the postulate that people—“agents”—behave in such a way as to maximize their “utility function.” In principle, the utility function could be almost anything, but in practice almost all applications of the theory in the mainstream economics equate utility with material self-interest. In the most basic

version, the utility is simply the dollar amount that an agent expects to get as a result of a certain action. The agent then should perform the action that yields the greatest payoff—this is what “maximizing utility” means. Agents that behave in ways that maximize their utility functions are “rational.”

Rational self-interested agents cannot join together in a functioning society—this could be one of the fundamental theorems in sociology. In a world where all individuals behave strictly rationally, armies would run away at the first shot (or would not even get together in the first place). Nobody would vote or pay taxes. IRS agents would accept bribes not to prosecute tax evaders, and then pass some fraction of that to the members of the Senate overseeing committee, to buy them off. The courts would make verdicts in favor of whoever can pay more, or has more power to intimidate the judges and juries. The police would let criminals go in exchange for part of their loot. Actually, I am painting too rosy a picture—when all behave in a purely self-interested manner, there will be no IRS, courts, or police. There could only be a Hobbesian war of all against all.

One kind of experiment, which has now been conducted by a number of investigative teams, is called “the public goods game.” Subjects are divided up in groups of four and given an initial endowment of $10 each. The game is played in 10 rounds. Every round each participant can contribute any part, from 0 to 10 dollars, to the group project. The experimenters first double the total amount contributed to the common account, and then divide it up equally among all participants. Thus, for each dollar contributed to the common pot, a participant gains back only 50 cents. On the other hand, he or she also gains 50 cents for each dollar contributed by others. If all participants contribute the maximum amount ($10), they would end up with $20 each, doubling their initial endowment. Clearly a rational, self-interested player will contribute nothing to the common pot, keeping the initial stake plus whatever gains come from the cooperative behavior of the others. In the best case, when the other three all contribute the maximum, the “free-rider” would get $15 in addition to the initial stake, for a total of $25. However, others will make the same calculation and also contribute nothing, so everybody is left with $10, instead of the maximum cooperative payoff of $20. Thus, the rational choice theory predicts that there will be no cooperation. Real people did not behave in the way predicted by the self-interest hypothesis. The average contribution to the common pot in the early rounds wa...

Experiments employing the public goods and similar games have now been conducted by many teams of investigators in many countries. In some studies, stakes were very high—equivalent to three months of salary. The general result is always the same. A substantial proportion of moralistic subjects always behaves in a cooperative, rather than rational fashion, and many people are willing to incur personal costs to punish cheaters. This is not to say, however, that all social groups are alike in their composition with respect to knaves, saints, and moralists. College students, for example, tend to be more cooperative than subjects coming from less-educated and poorer social strata. Graduate students in economics, on the other hand, tend to behave more selfishly than students from other disciplines (probably because they learn too much about rational choice in their classes!). Most interestingly, the strength of cooperative behavior tends to vary among different countries. Particularly good evidence for cross-cultural variation comes from studies that used the “ultimatum game,” which is simpler to set up and cheaper than the public goods game.

THE BEHAVIORAL EXPERIMENTS USING THE public goods and the ultimatum games decisively prove that Machiavelli’s self-interest premise was wrong. It is simply not true that all people behave in entirely self-interested manner. Some people—the knaves—are like that. However, other kinds of people, whom I have called the saints and the moralists, behave in prosocial ways. Furthermore, different societies have different mixtures of self-interested and cooperative individuals. Cultural practices (for example, the harambee system) and social institutions have a strong effect on whether and how collective action can be sustained.

For example, we know that interband warfare is very common among the chimps, our closest evolutionary relatives. Warfare is also nearly ubiquitous among the small-scale societies of hunter-gatherers and farmers. The anthropologist Lawrence H. Keeley presents evidence that somewhere between 20 percent and 60 percent of males in these societies die in wars. By an argument of “interpolation,” therefore, if both chimps and modern pre-state people practiced extensive warfare, so must have our human ancestors.

WHEN HUMANS EVOLVED THE ABILITY to cooperate with unrelated individuals, they relied on face-to-face interactions and memory to distinguish friends and acquaintances from the enemies or untrustworthy individuals in the group. There must have been an intense selection pressure for what science writer Malcolm Gladwell calls the “social channel capacity,” the ability to handle the complexities of living in large social groups. After all, to ensure cooperation you need to remember not only what each group member did to you, but also what they all did to each other. If Mary cheated Jane, she might also cheat you. When Bob fell asleep on guard duty, but John did not shun him, as he was supposed to do, it means John is failing to cooperate in a collective sanctioning task. Making a society work is a complicated business. But social channel capacity cannot be developed beyond a certain point—we cannot remember everyone on Earth, let alone what they have done to one another. As the size of the group increases, the number of relationships to remember explodes. If you belong to a group of 5 people, you only need to keep track of 10 separate relationships. If the group has 20 people, however, you need to remember 190 two-way relationships. The group size increased fourfold, but the number of relationships almost twenty-fold. Among the primates, humans live in the largest groups, and have the largest brains, but a limit is inescapable. “The figure of 150,” estimates the British anthrop...

One example of a symbol representing a social group is the totem of American Indians. As the great French sociologist Emile Durkheim recognized almost a century ago, the totem is “the symbol of the determined society called the clan. It is its flag; it is the sign by which each clan distinguishes itself from the others, the visible mark of its personality.” Another example is the standard of a Roman legion, called the Eagle. The Eagle was a sacred emblem of the legion; for most intents and purposes, it was the legion. It was better to die to a man than allow the enemy to capture the Eagle.

The capacity for symbolic thinking was the last great evolutionary innovation that made possible human ultrasociality. People now did not need to know personally another individual in order to determine whether to cooperate with him, or treat him as an enemy. Particularly good diagnostic features are religious observances and ritual actions. However, one could also look at the details of his clothing and ornamentation (including such permanent markings as tattoos or caste marks). One could listen to his dialect and observe his behavior.

Symbolic demarcation of the group made possible cooperating with strangers who were clearly marked as “one of us.” Symbols made it possible to identify with very large groups of “us,” groups that included many more people than the small circle any individual person could meet and get to know personally. In other words, the evolution of symbolic thinking enabled defining as “us” a group of any size.

SUMMING UP THE MANY STRANDS of argument followed in this chapter, we started with the puzzle of human ultrasociality—our ability to combine into cooperating groups consisting of millions of individuals. Two key adaptations enabled the evolution of ultrasociality. The first one was the moralist strategy: Cooperate when enough members in the group are also cooperating, and punish those who do not cooperate. A band that had enough moralists to tip its collective behavior to the cooperative equilibrium outcompeted, or even exterminated, bands that failed to cooperate. The second adaptation, the human ability to use symbolic markers for defining cooperating groups, allowed evolution of sociality to break through the limits of face-to-face interactions. The scale of human societies increased in a series of steps, from the village and clan to the tribe and tribal confederation, then to the state, empire, and civilization.

Religion was the glue that cemented the people together and gave the early Roman society an extremely high degree of asabiya. The cohesiveness of the society was so high that until the first century B.C. Romans did not need a police force to keep public order. The internally motivated discipline of early Romans, the formalized and ritualized behaviors of their culture, was enough to maintain public order. Punishment for many transgressions was a public declaration that the perpetrator acted dishonorably. According to Tacitus, for example, the only penalty suffered by a prostitute was the shame of having to profess her name before public magistrates.

One cannot overemphasize the importance of these personal qualities of early Romans to their subsequent rise as an imperial nation. Note how the Roman virtues served to limit individualism (gravity and constancy), strengthened ties within family (piety) and community (faith), and sacrifice for the common good (virtus). Romans held no physical or technological advantage over the peoples they conquered. An average Roman was smaller and weaker than an average Gaul. In a one-to-one duel, an average Roman would most likely lose to an average Gaul. On the other hand, a hundred Romans could hold even against a hundred of Gauls, and ten thousand Romans would easily defeat a Gallic army many times their number.

Two FACTORS EXPLAIN THE RISE of the Roman Empire: the high degree of internal cohesiveness of the Roman people, or asabiya, which reached a peak c. 200 B.C.; and the remarkable openness of the Romans to the incorporation of other peoples, often recent enemies. Both factors are necessary for building a world empire. Without high asabiya, an incipient imperial nation cannot survive being surrounded by powerful enemies in the early days of its expansion. Without the ability to truly incorporate the conquered people, an imperial nation cannot grow. Theoretically, there is an alternative: genocide or ethnic cleansing of conquered territory followed by colonization. Many imperial nations employed this strategy to some degree, but in practice all successful ones expanded mainly by cultural assimilation, rather than by biological reproduction. Openness to incorporation is a critical factor in explaining the difference between the imperial careers of the Romans and, say, Macedonians, as opposed to the Spartans, or Athenians.

I am not the first one to draw parallels between the Iberian Reconquista and the Russian conquest of the steppe. Several historians, including James Powers, have noted how the similarities of the frontier environment in these two societies resulted in many similar social institutions. Probably the most striking parallel is the remarkable egalitarianism and easy social mobility that characterized each society. As in Muscovy, the frontier warriors served either as cavalry or infantry. The mounted caballeros enjoyed a higher social status compared to the peones who fought on foot. They also had access to better land and pasturage, and better opportunity for booty in warfare.

When a raiding party returned, the town council announced a day on which everyone had to bring to the town plaza whatever booty they captured. All spoils, including livestock, clothing, arms, and precious metals, were auctioned. A portion of the proceeds was used to reward acts of heroism, but the bulk was distributed to everybody who participated in the expedition, with the size of the share dependent on the equipment. (Thus, cavalrymen received greater shares than those who fought on foot.) Anybody who tried to conceal an item was punished. The system curbed self-serving behavior that could be detrimental to the collective effort—all too many battles in history were lost because soldiers were more intent on plundering the captured camp of the enemy instead of nailing down victory. By making sure that each received his fair share, this method of booty division promoted cooperation on the battlefield. Clearly, the system was designed by a bunch of moralists!

The municipal militias played the key role in the Iberian Reconquest. There was no single center orchestrating military operations. Instead various Christian kingdoms (Navarre, Leon, Aragon, Portugal, and Castile) operated independently of each other, and often fought with each other.

The terrible famines of the fourteenth century left a deep imprint on the European psyche. One of the most famous fairy tales begins like this. “Hard by a great forest dwelt a poor woodcutter with his wife and his two children. The boy was called Hansel and the girl Gretel. He had little to bite and to break, and once when great dearth fell on the land, he could no longer procure even daily bread. Now when he thought over this by night in his bed, and tossed about in his anxiety, he groaned and said to his wife: ‘What is to become of us? How are we to feed our poor children, when we no longer have anything even for ourselves?’” Everybody knows what happened then. The children were abandoned in the forest and eventually found their way to a gingerbread house, where lived an old woman who wanted to cook and eat them.

The bubonic plague was the most spectacular cause of the plunge in population, but by no means the only one. After all, the population decline began even before the plague struck in 1348. The other causes of population decline were famine, warfare, and falling birth rates. Furthermore, the Black Death was not a unique, unprecedented event in world history. Other spectacular epidemics, such as the Plague of Athens in 430 B.C., the Antonine plague (A.D. 165-180), and the plagues of Justinian (A.D. 542-546), always strike during the same phase of the secular cycle—at, or just past, the population peak. Less spectacularly, the bubonic plague staged a comeback during the next secular cycle in Europe, and played an important role in the population declines of the seventeenth century (for example, the Great Plague of London of A.D. 1665). In general, epidemics almost always play a role in secular population declines. The most important factor explaining the spread of epidemics during this phase of the cycle is increased mobility of people, resulting from the migration of landless peasants to towns and cities, increased vagrancy, and the movement of rebel bands and troops. Additionally, large segments of population are undernourished, or on the brink of starvation, and therefore become susceptible to disease agents. Thus, the conditions of overpopulation create a fertile ground for the spread of epidemics, and also ensure a high death toll.

Every episode of internal warfare develops like an epidemic or a forest fire. In the beginning of the conflict, each act of violence triggers chains of revenge and counter-revenge. With time, participants lose all restraint, atrocities become common, and conflict escalates in an accelerating, explosive fashion. After the initial explosion, however, violence drags on and on, for years and sometimes even for decades. Sooner or later most people begin to yearn for the return of stability and an end to fighting. The most psychopathic and violent leaders get killed off or lose their supporters. Violence, like an epidemic or a forest fire, “burns out.” Even though the fundamental causes that brought the conflict on in the first place might still be operating, the prevailing social mood swings in favor of cessation of conflict at all costs, and an uneasy truce gradually takes hold. Those people, like the generation of Charles the Wise, who directly experienced the period of civil warfare, become “immunized” against it, and while they are in charge, they keep things stable. The peaceful period lasts for a human generation—between 20 and 30 years. Eventually, however, the conflict-scarred generation dies off or retires, and a new cohort arises, people who did not experience the horrors of civil war, and are not immunized against it. If the long-term social forces, which brought about the first outbreak of internal hostilities, are still operating, the society will slide into the se...

WE HAVE THUS SEEN THAT THE very stability and internal peace that strong empires impose contain within it the seeds of chaos. Stability and internal peace bring prosperity; prosperity causes population increase. Demographic growth leads to overpopulation; overpopulation causes lower wages, higher land rents, and falling per-capita incomes for the commoners. At first, low wages and high rents bring unparalleled wealth to the upper classes, but as their numbers and appetites grow, they too begin to suffer from falling incomes. Declining standards of life breed discontent and strife. The elites turn to the state for employment and additional income, and drive up its expenditures at the same time that the tax revenues decline because of the impoverished state of the population. When the state’s finances collapse, it loses control of the army and police. Freed from all restraints, strife among the upper classes escalates into civil war, and the discontent among the lower classes explodes into popular rebellions.

The collapse of order brings in its wake the four horsemen of apocalypse—famine, war, pestilence, and death. Population declines, and wages increase, while rents decrease. As incomes of commoners recover, the fortunes of the upper classes hit the bottom. Economic distress of the elites and lack of effective government feed the continuing internecine wars. But civil wars thin the ranks of the elites. Some die in factional fighting, others succumb to feuds with neighbors, and many just give up on trying to maintain their noble status and quietly slip into the ranks of commoners. Intra-elite competition subsides, allowing order to be restored. Stability and internal peace bring prosperity, and another secular cycle begins. “So peace brings warre and warre brings peace.”

Secular cycles are one of the most pervasive rhythms of history. They affect practically all facets of social life, from homicide rates to the styles of architecture. The phase of the secular cycle also determines the trend in social and economic inequality—whether it increases or decreases. This aspect is of particular interest because of the corrosive effect that glaring inequality has on the willingness of people to cooperate, which in turn underlies the capacity of societies for collective action. The effect of growing inequality is not limited to the escalation of “class warfare” between the poor and the rich. Increasing inequality within classes also leads to intense conflict of commoner versus commoner and

aristocrat versus aristocrat. Growing inequality, thus, is an important part of imperiopathosis-the process by which imperial nations lose their high asabiya. What are the social forces that cause inequality to grow, and how does inequality affect societies?

Although the model of Axtell and Epstein might seem to have little relation to reality (it is not much more than a computer game), its results illustrate a profound principle. The poorer agents are at a disadvantage, compared to the richer ones, and, as a result, tend to lose ground. By contrast, the richer agents tend to increase their stores of resources with time. In the language of dynamical sciences, this is called a “positive feedback loop”—the rich get richer, and the poor get poorer. Social scientists came up with another name for it, the “Matthew principle,” because the New Testament says: “For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath” (Mathew 13:12). The Matthew

Destruction of the great fortunes continued under the Tudors, who had it in for their over-rich and over-mighty subjects. The first two Tudors, Henry VII and Henry VIII, employed judicial murder with great effect, systematically exterminating all potential claimants to the English throne, who also happened to be among the richest landowners. Elizabeth I crafted a gentler method—a kind of “progressive taxation” scheme. When one of her subjects became too wealthy, she invited herself to his castle along with her whole court. After some weeks of dining and wining the queen and hundreds of her followers, the unfortunate host was financially ruined for many years to come, and was too busy paying off his debts to contemplate rebellion.

We do not know whether the real d‘Artagnan fought as many duels as the fictional one, but he probably fought his share, because France of his time was at the crest of the wave of a dueling epidemic. Dueling had almost disappeared in France during the fifteenth and early sixteenth centuries. Under François I and Henri II, a handful of judicial duels took place with royal sanction. As the numbers of surplus elites increased, however, so did their propensity to resolve their quarrels by murdering each other. After 1560, dueling for personal honor and without royal sanction became so common that contemporary commentators believed more noblemen died from it than in combat. One estimate was that 7,000 to 8,000 were killed in the two decades after 1588. It was said that Henri IV granted more than 6,000 pardons for the killing of gentlemen in duels during the first 10 years of the seventeenth century. Dueling was effectively eliminated only during the reign of Louis XIV, at the very end of d’Artagnan’s life. (He was killed in battle in 1673.)

The rise and fall of the dukes of Buckingham and de Guise graphically illustrates the dangers of extreme inequality for the social order. Rampant inequality feeds into the perception of the extant social order as unjust and illegitimate, and creates excellent breeding conditions for the rise of revolutionary ideologies. In the early modern period, these ideologies took the religious form. Later, the dominant revolutionary ideologies were nationalistic and Marxist. Today, we are seeing the rise of religious-based revolutionary ideologies again, such as the Wahhabism. There are huge differences between the English Puritans, the French Jacobins, the Russian Bolsheviks, and the Islamic Al Qaida, but there is at least one common thread running through all these ideologies and movements associated with them—a burning desire for social justice.

WHEN RICH GET RICHER AND POOR get poorer, cooperation between social classes is undermined. But the same process is operating within each class. When some nobles are growing conspicuously more wealthy, while the majority of nobility is increasingly impoverished, the elites become riven by factional conflicts. Within the secular cycle, as the disintegrative phase follows the integrative one, inequality rises and falls. A life cycle of an imperial nation usually extends over the course of two, three, or even four secular cycles. Every time the empire enters a disintegrative secular phase, the asabiya of its core nation is significantly degraded. Eventually, this process of imperiopathosis reaches its terminal phase—the imperial nation loses its ability to cooperate, and the empire collapses. Most empires, therefore, fall for internal reasons. Paraphrasing Arnold Toynbee, great empires die not by murder, but by suicide. Chapter 11 Wheels Within Wheels The Many Declines of the Roman Empire Few topics in history have generated so much heated controversy and so little enlightenment as the decline and fall of the Roman Empire.

general theory for the rise and decline of empires we have. The crucial variable in it is the collective capacity for action, the society’s asabiya. Competition between societies leads to asabiya increase, whereas competition within a society causes its asabiya to decline. As we have seen in Part I of this book, metaethnic frontiers, where groups and civilizations clash, are the crucibles within which high-asabiya societies are forged. The almost inevitable consequence of high capacity for collective action, however, is territorial expansion that pushes the frontiers away from the center and removes the very forces that fostered high asabiya in the first place. Thus, success breeds eventual failure; the rise carries within it the seeds of the fall—peace brings war, and war brings peace. In the language of nonlinear dynamics, rise-and-fall phenomena are explained by negative feedback loops.

A typical imperial nation goes through two or three, and sometimes even four secular cycles during the course of its life. Finally, the disintegrative phase of each secular cycle will see two or three waves of political instability and civil warfare, separated by periods of fragile peace. The characteristic time scales, therefore, are a millennium for the asabiya cycle, 2 to 3 centuries for a secular cycle, and 40 to 60 years (two generations) for fathers-and-sons cycles. These are just orders of magnitude; there is no exact periodicity in any of these processes.

Massive population growth, coupled with the Roman custom of equal division of property among the heirs, resulted in rapidly increasing economic inequality. Several generations of property division among multiple heirs resulted in each heir’s share being grossly insufficient for feeding the family. The history was repeating itself, again. Some impoverished landholders were forced to sell their land to the aristocrats flush with the spoils of Rome’s conquests and eager to invest their fortune in land. Others tried to go on, ran up unsustainable debt levels, and also lost their land (or even freedom). The end result of this process was the gradual disappearance of the class of small landowners, which had been the backbone of the Roman state and army. Some citizens, unable to repay their debts, were turned into slaves. Others sold themselves into slavery because they were unable to feed themselves. The majority became landless proletarians and either worked the land of aristocratic landowners or drifted to Rome and other large cities in search of work. Finally, a few—those with few children, the thrifty and hardworking, or simply the lucky ones—grew in wealth and aspired to better their social standing.

Whereas in fourth century B.C. the majority of Roman citizens were in the “middle class”—they owned enough land to feed themselves and their families—two centuries later few of such free smallholders remained. The upper and lower classes of the Roman society had drifted apart. At the bottom were the vast multitudes of slaves, freedmen, and proletarians; at the top, all wealth and power was concentrated in the hands of a small group of aristocrats. Inequality was further exacerbated by the Roman institution of slavery. Millions of slaves, captured during the wars of conquest, flooded Italy during the second century B.C. Because slaves had no human rights, and legally could hold no property (in practice, some masters allowed them to accumulate funds to buy themselves out of slavery), their presence in massive numbers made the Roman society during the late Republic even more unequal than is usual in pre-industrial states. One of the most striking developments in the second century B.C. was the growth of both the numbers and wealth of the Roman elites. The scale of senatorial fortunes grew at an astronomical rate. One of the foremost members of the Roman aristocracy, L. Aemilius Paullus, who put an end to the kingdom of Macedon in 167, left a fortune of a measly 1.44 million sesterces upon death. A century later, the fortune of the famous orator Cicero was 13 million sesterces. And Cicero was a “new man.” (He was born in a provincial town and was the first of his clan to enter...

Conspicuous consumption is inherently divisive because it draws boundaries between the haves and the have-nots. It elicits envy and weakens solidarity. But it is even more important as a symptom of deeper processes—growing inequality and within-group competition for resources and power that gradually undermine group solidarity.

A TURNING POINT WAS THUS CROSSED during the second century B.C. Whereas the Roman aristocrats of the early Republic competed in who could die for patria in the most glorious way, in the late Republic they competed in who could throw the most sumptuous banquet. In 275 B.C., possession of 10 pounds of silver plate was considered as “anti-social behavior,” two centuries later possession of 10,000 pounds of silver was a source of pride for the owner.

1993, Robert Putnam published Making Democracy Work: Civic Traditions in Modern Italy. “Social capital,” as Putnam explains, “refers to features of social organization, such as trust, norms, and networks that can improve the efficiency of society by facilitating coordinated actions.” Putnam’s social capital is asabiya for modern democratic societies, with an emphasis on its nonmilitary aspects. Along with a growing number of professional scientists and lay readers, I applaud Putnam’s work, but I prefer Ibn Khaldun’s term asabiya, acknowledging as it does the long history of this particular approach to the understanding of human affairs.

Well before Putnam, and even before the Italian experiment in devolution of powers to regional governments, anthropologists knew that something was wrong with the society of the Italian south—the Mezzogiorno, as it is known in Italian. A particularly interesting study is that by the American anthropologist Edward Banfield, who spent a number of years in a southern Italian village during the 1950s and 1960s. In 1967, he published a book detailing his findings, The Moral Basis of the Backward Society. Banfield describes the extreme atomization of the southern Italian society, in which all cooperative efforts are limited to the smallest possible societal unit, the family. Relations even to such kin as cousins, and sometimes even grown-up siblings, are rife with distrust and lack of cooperation. Community-level cooperative efforts are virtually impossible. Banfield called this type of society “amoral familism,” and defined its basic philosophy as this: “Maximize the material, short-run advantage of the nuclear family; assume that all others will do likewise.” This is the philosophy of the knave, in the technical sense of the term that I introduced in Part I. No wonder, then, that the Mezzogiorno society cannot function as a society. Even calling it a society is misleading; it is really a conglomerate of atomized nuclear families.

WHEN TRYING TO UNDERSTAND THE amoral familism of the Italian south, Edward Banfield drew an explicit contrast with the vibrant civic culture of a small Midwestern American town in the 1950s, a social group with which he was intimately familiar. Banfield’s observations echo in a remarkable way those of Alexis de Tocqueville. We have already had a chance to consult Tocqueville’s study of the civic life in America. But Tocqueville also traveled in Naples and Sicily as a young man, before he went to America, and in the long essay he wrote describing the trip he remarked on the culture of distrust and duplicity that pervaded the southern Italian society. It is remarkable how stable this particular manifestation of asabiya (or, rather, lack of it) has been in that region.