The causes, development, and outcomes of revolutions vary greatly. In some revolutions--as in China in 1949 or Cuba in 1959--a planned assault by a revolutionary organization on the existing government played a critical role. In others--as in England in 1640 and France in 1789--revolutionary organizations only developed once the ruling government had already called assemblies of elites to deal with an ongoing crisis. And in yet other revolutions--as in Russia in 1917 and Iran in 1979--revolutionary leaders were active early but only took power opportunistically, once a combination of strikes, demonstrations, and popular uprisings by diverse groups had already led to the abdication of the ruler. No one pattern can serve as an archetype for all others, nor is there a single formula for how revolutions are created. The term "revolution" denotes a broad generic type, and actual revolutions vary in many details.

Scholars have yet to agree on a precise definition of revolution. Some writers will only consider fundamental changes in institutions as revolutions; others prefer to make the degree of change a variable to be explored. Some authors consider violence to be intrinsic to revolutions; others consider violence to be a common, but not crucial, element in revolutionary change. Some scholars think it best to define revolutions only in terms of objective criteria; others think it vital to include a sense of the purpose and meaning of revolutionary actions.

Though not universally accepted, the following definition will guide this survey: a political revolution is a process of change in the institutions of a government--and the principles on which they are based--that involves the collapse or overthrow of the authority of the existing government, in which the change in institutions occurs mainly through the actions of those living under that government, and in which the change is motivated by beliefs that the principles on which the existing government is based are irremediably ineffective or unjust.

Events that do not involve the collapse or overthrow of government authority are not revolutions. The British reform movement of 1828-32, the women's suffrage movement, and the South African reforms of 1984 were major reforms, with dramatic and fundamental consequences, but not political revolutions. Also, far-reaching changes that are the result of military occupation and the refashioning of government institutions mainly by outside powers are not revolutions: the constitutions settled on the defeated WWII powers by the Allies marked fundamental changes in the political history of Germany and Japan, but not revolutions. And although rebellions, revolts, coups d'etat, dynastic succession struggles, and civil wars over such issues as corruption, resource control, or levels of taxation are examples of political violence, they are not revolutions if no attempt is made to remodel the underlying principles of governance. The fall of Chinese, Ottoman, and Mughal emperors, the Wars of the Roses in England, and varied coups that simply rotate rulers or factions, or cases where military leaders seize power to "guard" existing constitutions, are not revolutions, for no fundamental change in the principles of governance occurred.

In some cases, a collapse in state authority seems near, or occurs to only a limited degree, but the other elements of revolution are present. For example, in South Africa from 1960 to 1984 government authority was persistently challenged, fundamental change occurred, and the principles of the Mrikaner government were widely believed unjust. In Germany and other central European countries in 1848, and in Russia in 1905, collapses in state authority took place for a limited time, or in limited regions, and many actors thought these regimes ineffective or unjust, yet the regimes recovered and only enacted reforms without changing their principles of absolute monarchy or imperial rule. In these cases, we may speak of "revolutionary situations" that produced either reforms or unsuccessful revolutions.

"Social revolutions" meet two additional criteria: first, the collapse or overthrow of government involves the mass mobilization of popular groups, and second, changes also occur in the principles underlying the distribution of wealth and elite status. Social revolutions that occurred in countries that by their size or power were one of the great powers of their era are sometimes called "great revolutions," namely those of France in 1789, Russia in 1917, and China in 1949.

This article will consider two approaches to understanding revolutions:

(1) examining the history of revolutions, exploring the empirical variety of the phenomenon; and (2) examining the theory of revolutions, reviewing social scientists' attempts to uncover the causes and effects of revolutions by comparing and dissecting various revolutions and their constituent elements.

The Roman republic was founded through the overthrow of Etruscan Kings who ruled the communities near the mouth of the Tiber. While the Republic prospered and grew for several centuries, the late Republic was wracked by civil wars between elite factions, which were finally ended by the development of imperial rule under Augustus. The decades in which the authority of the Roman Senate gave way to the rule of the Caesars has been described as a second Roman revolution.

The Renaissance and the Reformation witnessed numerous struggles among Kings and Popes, secular lords and prelates, and leaders of diverse religions and factions. Although in most cases these were territorial and dynastic wars, in some cases parties representing different principles of governance contended. In Italy, the governments of city-states saw struggles similar to those of the Greek city-states, with republican and aristocratic factions contending for power in a series of revolutions. Their most famous revolutionary leader was Girolamo Savonarola, who led a successful campaign for citizen rule in Florence against the Medicis in 1994. However, he was executed in 1498, and the Medicis returned to power in 1512.

It was in the context of these struggles that the word "revolution" was first applied to political events, denoting the cyclic fortunes of the parties who alternately rose high in victory and were brought low in defeat. In Britain, Charles I's efforts to reduce his dependence on the landed elite assembled in Parliament led to a confrontation in 1640 over a variety of Crown initiatives in state finance and church organization. The breadth of the conflicts--involving a revolt by Scottish Presbyterian elites and uprisings by Irish peasants as well religious and political divisions in England--split the British elites into Royalist and Parliamentarian factions. A series of civil wars among these factions from 1641 to 1649 led to the execution of the King. More important, the principles of governance by King, aristocracy, and a monopolistic Church were declared wanting, and the monarchy, House of Lords, and established Church were abolished. The new government consisted of a single assembly led by a Lord Protector of the Commonwealth (the title taken by Oliver Cromwell, the military leader of the Parliamentary forces). But it was not successful in establishing lasting political institutions. Factional fighting led to the dissolution of Parliament, and Cromwell ruled through increasingly unpopular military lieutenants in the English counties. After Cromwell's death in 1660, the monarchy, Lords, and Anglican Church were restored. The 17th century English philosopher Thomas Hobbes spoke of these changes too as a "revolution," with power moving in a cycle from King to Parliament to Cromwell and back t6 the King once again.

In 1689, further conflicts over religion and concern about the King's power led to a dynastic contest, with William of Orange, supported by English Protestant elites, invading England and wresting the Crown from the Catholic King James II. Although this episode was dubbed "the Glorious Revolution" by William's supporters, it involved no significant challenge to the basic principle that England should be ruled by a King and Parliament of landed elites, both united in support of the Anglican church. Nonetheless, it did have a far-reaching impact. For the Act of Parliament that recognized William's claim to the throne enunciated certain rights and responsibilities of the King and Parliament, explicitly balancing their roles. Although these roles were not new, by putting that balance in writing for the first time the Act formalized a notion of constitutionally limited rule that had a major influence on future revolutions.

Also in the 16th and 17th centuries (1566-1648), the Netherlands subjects of the Catholic Habsburg dynasty fought a series of battles aimed at overturning dynastic rule. Although not successful in freeing all the lowlands from Spain, this revolution did succeed in creating a new state in the northern Dutch provinces, governed as an oligarchic republic by a primarily Protestant local elite.

A few observations hold of all the revolutions mentioned so far: although there were sporadic attacks by peasants on landlords or their property, and some urban tumults, most popular mobilization took place under elite control, usually as recruitment into elite-led armies that challenged the military forces of the old regime. Second, none of the revolutions created, in a single rapid change, a permanent fundamental alteration of their societies. In all cases (including the Netherlands revolutions, where success ebbed and flowed for almost a century) the fortunes of different parties alternated, and only in the Dutch case did the monarchical or dynastic authorities fail to re-establish their control. Thus these events followed the course of "revolutions" in their original, circular, sense. Finally, all the revolutionary parties justified their actions in terms of concrete parties or religions, rather than abstract rights, constitutions, or universal secular ideals. English Parliamentarians spoke for the rights of Englishmen. Dutch Patriots opposed the Catholic Habsburg regime. Greek and Italian city-states rang with arguments over the virtues of citizens or the follies of democratic assemblies and the finer judgment of elite oligarchies, yet these remained tied to local concerns, and were mainly supports to complaints against the vices of particular parties or rulers. Even the Athenians, who sought to spread democratic regimes throughout their empire, did not think of democracy as suitable for any peoples other than Greeks. The era of mass uprisings, universal ideals, and sweeping and permanent change still lay in the future.

The "Great" Revolutions

Despite the differences in the times and places that they occurred, the "great revolutions" of France in 1789, Russia in 1917, and China in 1949 share a number of key characteristics. First, their ideologies were rooted in the philosophies of the Enlightenment, a period which firmly believed in the necessity of progress brought by the action of human reason to overturn false authorities and discover enduring, universal truths. Each revolutionary leadership--particularly the French populist Robespierre, the Russian revolutionaries Lenin, Trotsky, and Stalin, and the Chinese leaders Mao Zedong and Zhou Enlai--sought to create an ideal regime, confident that there was only virtue in destroying the old order, and persuaded that they could rationally conceive, justify, and create a superior society.

Second, these revolutions created long-lasting changes in the political, economic, and social institutions of the societies in which they occurred. This is not to say that all or even most of the specific institutional changes they brought were permanent. But in every case, the ruling elites under the old regime--a privileged nobility based on the birth in France, a state nobility titled and led by the Tsar in Russia, and a Confucian-trained bureaucratic elite in China--had their roles permanently reduced or eliminated, and fundamental changes in state administration, economic organization, and the standing of organized religion occurred that were never reversed.

Third, each revolution's success depended in large measure on the support of popular groups--urban workers and peasants--who took action against the state or old regime elites. The mobilization of these groups into politics continued during the course of the revolution, with the new regime building mass-based armies through recruitment of its popular base. These armies were involved in extensive wars against counterrevolutionary forces, both internal and external. In each case, warfare to make or defend the revolution became the cardinal organizing principle of the early revolutionary government. Also in each case, the revolutionary regimes at some point successfully expanded their domain, France controlling much of Europe under Napoleon, Russia building a soviet empire that included informal control of eastern Europe after WWII, and China controlling and colonizing Tibet.

Fourth, the revolutionary leadership responded to the pressures of conflict with counterrevolutionary forces by seeking to purge their countries and regimes of any active or potential counter-revolutionary actors. These efforts led to periods of state "terror," in which individuals or whole groups suspected of disloyalty would be sought out and harshly punished, often by summary execution or staged trials.

Fifth, the revolutionary regimes emerged from their struggles with larger, more highly centralized, and more powerful governments than had existed under the old regime. Napoleon in France, Stalin in Russia, and Mao in China were military heroes who emerged as absolute leaders controlling vast bureaucracies and mass armies, which molded details of life left untouched by the old regime. Moreover, these strengthened revolutionary regimes took a missionary role, confident that the universal truths of their revolution could be exported to other societies.

Sixth, and only recently apparent in the cases of Russia and China, the revolutionary regimes could not be sustained. In France, major aspects of the revolutionary project faded after the fall of Robespierre. In Russia, the communist party and its socialist policies collapsed in a combination of economic failures and factional conflicts. And in China, the communist economic and social goals of the revolution have been explicitly abandoned, and the continued monopoly of power of the communist party is in question, most recently challenged by mass student and workers protests in 1989.

Despite these many similarities, there were important differences in the causes and development of these revolutions. In 18th century France, arguably the richest and most powerful nation of its day, the revolution developed mainly out of a fiscal crises and intra-elite conflicts. In the 1780s, after two decades of experimentation with fiscal and economic reforms, the Crown acknowledged that its tax system would soon be unable to provide sufficient revenues for its bureaucratic and military responsibilities, and asked help from the notables of the kingdom to refashion its finances. But the fiscal system was so enmeshed with principles of elite privilege that a simple solution could not be found. Instead, conflicts among the King and various elite groups rent the elite assemblies that were called to debate the issues of privilege and taxation.

These conflicts among the state and its elites, along with the fervent declarations on all sides that change was necessary, encouraged peasants and workers to anticipate changes that would benefit them as well. When harvests failed in 1788, peasants in many areas of France refused to pay dues to their landlords, and in some cases attacked estates to seize and destroy the feudal charters that gave landlords political and fiscal rights over their tenants' domains. Moreover, urban workers watched the elite conflicts with concern, fearful that the King or conservative elites would halt the process of reform that they thought would bring lower prices for bread. In July 1789, reacting to the King's closure of the assembly, a crowd of Parisians attacked the royal prison of the Bastille, and forced its commander to surrender. Capitulating to fears of growing mob violence, the Crown reopened discussions with the assembly. Also reacting to the swelling crowds in Paris demanding change, and the fait accompli of peasants denying feudal obligations, the assembly took on the task of making sweeping changes in France's economy and political institutions.

Over the next ten years, conflicts between moderates and radicals, efforts by the King and emigre conservatives to enlist foreign support to reverse the revolution, and actions by the revolutionary government in Paris to raise funds by taking control of the Church and remodeling local government gave rise to increasingly violent conflicts. The revolutionary government faced urban riots, regional rebellions, and international warfare. Taking emergency powers, a Committee of Public Safety under the leadership of Robespierre used dictatorial powers to eliminate internal and external enemies. But Robespierre's enemies had him executed as well. Internal stability developed only after 1799, when Napoleon staged a coup and took power.

Napoleon built on the administrative changes of the revolution, led the armies of the revolution to conquer much of Europe, and used the loot of conquest to help stabilize political and economic conditions in France. Going from success to success, Napoleon faltered only when he sought to carry French power all the way to Moscow. After losing much of his army to long marches amidst the Russian winter, he returned to Paris in defeat. In a last bid ~o regain his power, in 1815 Napoleon led a French army against the combined forces of Britain and Prussia at Waterloo, only to be defeated and exiled. The monarchy was restored to France. Republicans, monarchists, and Bonapartists would contend for power for the next sixty years; but for the moment the French Revolution was at an end.

In contrast to France, Russia in 1917 was arguably the poorest and most backward of the major European powers. Its heavy industries, concentrated in Moscow and St. Petersburg, served mainly the state's needs for military infrastructure and supplies, rather than consumer markets. Its agriculture remained primitive, marked by its relatively recent emergence from serfdom. Its armies, though large, were poorly equipped; its merchant and professional classes small, and its people generally poor. The state's power rested not on the support of a powerful social elite, but on its absolute command of the military and bureaucracy, and the absence of any social groups to counter them.

If in France contention with a powerful social elite started the revolution, in Russia it was contention with a foreign adversary. Stung by defeat by Japan in 1905, Russia entered WWI hoping for better. Instead, Germany's armies chewed up the Tsar's forces, leading to the collapse and mass desertion of many units. By 1917, humiliated and his army in tatters, facing strikes in the factories and growing peasant unrest in the countryside, the Tsar abdicated. Leading professionals and intellectuals proposed the election of a national assembly to replace the crumbling Tsarist regime, and a moderate government was elected under the leadership of Alexander Kerensky. Yet this moderate regime lasted only a few months.

Unable to bring itself to accept defeat in the war, or to respond immediately to the growing demands of workers for higher wages and of peasants for ownership of the lands they worked, the Kerensky government temporized. In October 1917, Kerensky was overthrown in a coup. The coup was carried out by a workers' movement, mobilizing mainly factory workers in state enterprises in St. Petersburg and Moscow, joined by mutinous military units, and led by the Bolshevik wing of the Russian communist party, whose leaders promised to give power to the workers' congresses (the soviets) and respond to the most pressing demands of Russians with the straightforward slogan of "Peace, Bread, and Land."

As in France, the new revolutionary government did not go unchallenged, and the next four years were spent organizing armies to contend with counterrevolutionary forces both at home and from abroad. By 1921, however, the Bolshevik Party under Lenin and its armies under Trotsky were victorious. Rebuilding the state bureaucracy through the recruitment of worker cadres to serve alongside (and keep watch on) former Tsarist officials, the Bolsheviks developed a dual political structure in which the Communist Party hierarchy operated in parallel with, but also in command over, the civil and military bureaucracies.

Upon Lenin's death, infighting broke out in the Party over how best to maintain the Revolution and build Russia's economic and political strength. Stalin, who emerged as the ultimate leader of the Party in the 1930s, undertook three major campaigns that produced millions of casualties. The first, against the peasantry, drew revenues from the countryside to support economic development, often to the point of leaving the peasants literally starving. The second, against his actual and suspected opponents in the Party, became a large scale purge using surveillance and terror tactics to consolidate his dominance of the state. The legacy of this campaign was a huge secret police, a network of state prisons, and the complete subordination of all ideology and scientific thought to the demands of the Party. The third, the war against Germany in WWII was the most disastrous in terms of casualties. However, Russian heroism in the sieges of Leningrad and Stalingrad; the skill of the regime in moving heavy industry beyond the range of the advancing German armies; and the powerful, ally-aided counterattack that took Russian troops to Berlin and established Soviet hegemony over Eastern Europe won Stalin and the Party the gratitude of a war-weary population, who saluted his victory in the "Great Patriotic War."

For three decades after WWII, the Party presided over a dramatic industrial and scientific rebuilding. After Stalin's death, the Party attempted to base its power on economic growth and military prestige, rather than sheer coercive terror. Becoming an economic and military superpower, and contesting for the allegiance of Third World countries with the United States, and its west European allies, the Soviet regime seemed frighteningly strong.

Yet from 1975, the centrally planned economy began to slow down. The production of goods declined in quality and then in volume. Agriculture remained primitive compared to European production. Overcome at last by the strains of supporting a military superpower's budget on a developing nation's economy, in the late 1980s the Party leadership under Gorbachev sought to reform the Party's stranglehold on all aspects of the economy. However, criticism and reform of the Party only undermined its appeal. In 1991, when conservatives in the Party attempted a coup to counter Gorbachev's reforms, neither the coup plotters nor Gorbachev received public support. Instead, Boris Yeltsin, a nationalist politician and former Party member, attracted support for a policy of taking government away from the Communist Party, and Russia out of the Soviet Union. Nationalist leaders with similar programs came forth in the Ukraine, the Baltic states, the Caucasus, and Central Asia, and in a few months, the Soviet Union dissolved into over a dozen newly independent states. Although some of these states retained communist leaders, while others elected non-communist nationalists, and still others succumbed to civil war, the letters "USSR" were stripped off the Kremlin walls; the revolutionary state of the Union of Soviet Socialist Republics was no more.

China's process of revolution was different from those of both France and Russia. Although military defeat of the old regime was a factor, neither urban workers' uprisings nor autonomous peasant attacks on landlords played a key role in the overturning or collapse of the old regime. Instead, the revolutionary forces built up a patriotic army in the countryside that liberated large regions from central government control, and eventually was able to drive its opponents out of the country.

Although the largest and traditionally strongest power in Asia, China had suffered throughout the 19th century from humiliating defeats at the hands of Western powers. Its major seaports were reduced to colonial enclaves, and its government was forced to pay reparations to the Western nations that it resisted. Overturned in 1911 by provincial bureaucrats and businessmen who sought a more modern form of government under the Republican leadership of Sun Yat-sen, the Imperial regime gave way to a contending congeries of warlords and would-be modernizing leaders. In the l920s, one of the latter, the general Chiang Kai-shek, led a campaign that established military control of China. Yet his domination lasted hardly a decade before a Japanese invasion and partial conquest of China pushed his regime into the interior.

Among the would-be modernizers of China, as well as republicans and military nationalists, there was a small group of intellectuals who sought to establish a Communist Party that would lead a soviet-style revolution. Despite help from Stalin, their efforts in the 1920 to mobilize workers for an urban insurrection ended in disaster. Unlike the defeated Tsarist regime, the still-powerful military forces of Chiang efficiently suppressed the urban uprisings, sending the Communist leaders fleeing into the countryside.

There the Communists regrouped. Deciding that the had to turn to guerrilla warfare, and organize the peasantry against Chiang's regime, Mao developed a strategy of intervening in conflicts between peasants and landlords, and providing various kinds of services, to win the peasants' support. In some areas, the Communist Party seized land from wealthy landlords and divided it among poor peasant families. In other areas, the Party simply guaranteed a maximum level of landlord rents. Everywhere, they reorganized the villages, economically and politically.

Although Chiang's forces pursued Mao into the countryside, eventually forcing the Communists to undertake a "long march" of over a thousand miles to the remote northwest, the Japanese invasion prevented Chiang from giving full attention to eliminating the Communists. Instead, Mao and Chiang agreed to a united front against the Japanese. In practice, this meant that Chiang's forces retreated to the south, leaving most of the north and west open to Mao's efforts at building a peasant base.

After the allied defeat of the Japanese in 1945, Mao and Chiang returned to their unfinished battle. Two decades of building a popular base in the countryside had enabled the Communists to create an effective army of supporters. Chiang, in contrast, dependent on allied aid and unable to repress the corruption of his own forces, had lost or alienated most of his domestic support. With military support from Russia, Mao defeated Chiang's forces in a massive civil war, and in 1949 took control of mainland China while the remnant of Chiang's regime fled to Taiwan.

The French, Russian, and Chinese Revolutions, despite their shared features, thus represent three distinctive paths to revolution: elite rebellion with popular urban and rural support; mobilization of industrial workers under the leadership of a professional revolutionary Party to seize power from a collapsing regime; and rural peasant mobilization of a military force to wrest power from the existing government. Each of these paths has served as a model for different modern revolutions.

Modern Revolutions

Since 1750, revolutions have occurred in dozens of states. They are so many and so varied that space precludes a detailed description of each. However, they can be surveyed according to the character of the regimes that they aimed to replace: colonial regimes, empires, monarchies, dictatorships, and even republics.

The first major anti-colonial revolutions were those in the Americas, including the American Revolution against Britain (1776), the Latin American Revolutions of Independence from Spain (1808-1830), and the Haitian Revolution against France (1795). In the revolutions against Britain and Spain, elites native to the colonies opposed governance from Europe, seeking instead to erect independent regimes. In both cases, constitutional republics emerged, led by military heroes (George Washington in the United States, Simon Bolivar in South America).

But in the long term, these revolutions diverged. In the United States, a large small-holder population, which grew with westward settlement, was incorporated into the political system, preventing any consolidation of political control by landed elites. In the 1860s, conflicts between the slave-holding southern states and the free (slavery-prohibiting) northern states erupted into Civil War. In a sense, this conflict too was a revolution, for the southern states briefly threw off the authority of the government in Washington, and created a political system in which large landowners had a privileged role, in contrast to the more pluralist, small farmer and urban artisan based politics of the rest of the United States. Yet this attempted revolution failed with a complete victory of the Union forces over those of the Southern Confederacy.

In Latin America, however, the confinement of major settlement to the areas of Spanish rule and the prevalence of the hacienda system of concentrated landowning meant a polarization of power and the emergence of landed oligarchies. For the next century, factions of these oligarchies, with their allies in the military, would contend for power. Although the principles of constitutional government and democratic governance were rarely questioned, in practice governance was subject to frequent coups and the alternation of republican governments and military guardianships in a seemingly unending dance that continues in some Latin American nations to this day.

A second wave of anti-colonial revolutions developed against European-imposed governments in Africa and Asia after World War II. In Africa, Algeria's struggle against France (1954-1962) was the most drawn out and violent of the anti-colonial revolutions. However, notable revolutions or attempts at revolution also occurred in Kenya and Zimbabwe (against British settler regimes), and in Guinea-Bisseau, Angola and Mozambique (against Portuguese colonial rule). In most cases, the revolutions followed the Chinese model, with guerrilla war against the government organized from the countryside.

In Asia, a number of colonial territories sought their independence in the period immediately following Japan's defeat and withdrawal from mainland Asia. India was the largest of these. India's Independence Movement is not always acknowledged as a revolution, due to the extraordinarily modest violence of its Ghandi-led mass mobilization. However, no less than the American wars of Independence, India's elite-led mobilization forcibly expelled British rule. Unfortunately, soon after independence, India was split by civil and religious conflicts, first with Pakistan separating from India, then with Bangladesh seceding from Pakistan. India has remained a steadfast constitutional democracy, with only a brief interlude of emergency rule. But Pakistan and Bangladesh have alternated periods of military and democratic regimes.

In Vietnam, Laos, and Cambodia (French) and in Indonesia (Dutch), the colonial powers attempted to restore their regimes after 1945, and were only expelled through force. Yet after the French were defeated in 1954, the United States sought to prevent a complete victory by the Communist forces under Ho Chi Minh by backing conservative dictatorships in South Vietnam and Cambodia. After another two decades of fighting, the Americans were finally forced to withdraw, leading to a consolidated Communist state in Vietnam. However, in Cambodia the defeat of the American-supported dictatorship gave rise to a struggle for power between the traditional royal family and a radical communist group, the Khmer Rouge. Briefly winning power, the latter undertook an extraordinary genocidal campaign to eradicate western influences on Cambodian society. Only intervention by Vietnam, and later the UN, to expel the Khmer Rouge and restore the royal family stemmed the slaughter. In Indonesia the expulsion of the Dutch led to personalist politics under powerful military leaders.

The 19th and 20th centuries also produced numerous nationalist, anti-imperial revolutions. In most cases, these revolutions sought to free particular peoples from multi-national empires, although in some cases they aimed at assembling smaller states into larger ones. Thus the German and Italian Revolutions of 1848 sought not only to overturn royal authority, but to join various states into united national republics.

In Europe, the main nationalist revolutions were those of Greece against the Ottomans (1821), of Poland against Russia (1830), of Italy and Hungary against the Habsburg empire (1848), of Rumania against Russia (1848), and of Prussia and other Germany states against their dynastic rulers (1848). Of all these, only the Greeks were successful, the rest being turned back, often with the aid of Russian troops.

Other important nationalist revolutions were those in Arabia (the Saudi Revolution), which created an Islamic fundamentalist state, and in Turkey, where Kemal Attaturk built a secular nationalist state on the ruins of the collapsing Ottoman Empire. In the 1990s, nationalist revolutions contributed communist to the collapse of the USSR, with various new regimes replacing leadership in Eastern Europe and the former Soviet republics.

In addition, most of Europe's remaining monarchies were dispatched by republican revolutions in the 19th and 20th centuries. Germany's Hohenzollern dynasty was overthrown in the aftermath of WWI, giving way to the dynamic but unstable Weimar republic. France's last King was dethroned in 1848, in a revolution that initially created a republic, but eventually yielded to a Bonapartist coup. Another urban rising in Paris, in 1871, ended the rule of Napoleon III, and finally ushered in an age of stable republican regimes in France. In 1860, the Kingdom of Naples was overrun by the revolutionary forces of Garibaldi, whose success led to the unification of Italy. And in 1910, a revolution overthrew Manuel II of Portugal, creating a short-lived republic which gave way to dictatorship.

Traditional regimes in Asia and Africa were challenged as well. In China, the first genuinely revolutionary movement was the Taiping rebellion of the mid-l9th century, which aimed at erecting a Christian-inspired messianic state. Although Taiping was a failure, it helped pave the way for a republican revolution that overthrew the Imperial dynasty in 1911. In Japan, the Shoguns who had ruled the island nation since the 17th century were overturned in 1865 by a coalition of provincial governors and reforming samurai. The new Meiji regime modernized Japan's political and social system by abolishing the Shogunate and samurai ranks and importing Western science, industry, and government institutions. In Iran, a modernizing constitutional revolution occurred in 1905. In Egypt, the royal family was overthrown in 9152 by the nationalist regime of Gamal Abdel Nasser, whose success inspired other modernizing, military revolutions in the Middle East, most notably in Yemen, Iraq, and the Sudan. In Ethiopia, a traditional empire was overthrown by a military coup in 1974, whose efforts at revolutionary transformation provoked nationalist revolts in Eritrea and Tigre. In Mghanistan, the traditional ruler Zahir shah was overthrown in 1973 and a republic declared.

While nationalist and anti-colonial revolutions, as well as more peaceful transitions from colonial rule, often attempted to create constitutional democratic regimes, such regimes rarely rested on the kind of broad civil society, with a dominant strata of small farmers, artisans, modest merchants, and skilled workers, necessary for self-rule. Instead, a polarized class-structure dominated by a wealthy elite perverted democratic principles and produced incessant factional strife, with various elite factions, including military and civilian rulers, vying for the right to "defend the nation and the constitution" by controlling the state. In some cases, fairly stable dictatorial regimes emerged, in which a single individual managed to control civil and military patronage and concentrate most power in his own hands. Although these regimes continued to operate with constitutional assemblies, and left the basic class structure of society untouched, they in fact rigged elections and turned the constitutional courts and legislatures into mere facades. Notable examples of such personalistic dictatorships emerged in the Philippines (Ferdinand Marcos), South Korea (Syngman Rhee), Cuba (Fulgencio Batista), Portugal (Antonio Salazar), Mexico (Porfino Diaz), Iran (Shah Pahlevi), and Nicaragua (the Somozas). In each of these countries, after decades of successful personalist rule, the dictatorships began to falter. Corruption, increased attacks on the remaining authority of domestic elites, and economic crises undermined elite support for the dictators. At the same time, the growth of a middle class of workers and professionals led to greater demands for political openness. When combined with the mobilization of peasants or the urban poor, who sought relief from exploitative landowners or from declining employment and wages, these changes isolated the dictators.

The first of these dictators to fall was Diaz in Mexico, whose rigged election in 1910 provoked rural and urban revolts. Unfortunately, varied popular and elite factions could not settle their differences, and attempts at radical revolution, limited constitutionalism, and counterrevolution wracked the country in a decade-long civil war. Next was Batista in Cuba, overthrown in 1959 by an peasant-urban coalition led by Fidel Castro. In South Korea, popular riots ended Rhee's regime in 1960. In 1974, radicals in the Portuguese military toppled Marcello Caetano, who had inherited Salazar's dictatorship, triggering an outpouring of popular support. In 1979, the Shah of Iran was toppled by mass strikes and urban protests. The same year, urban and rural guerrillas supporting the Sandinista Party forced the last Somoza in Nicaragua to flee. And in the Philippines in 1986, protests against a rigged election drove Marcos from power. Although similar in their targets, the sources and outcomes of these revolutions ranged widely. In Mexico, Nicaragua, and Cuba peasant armies played a significant role. In Korea, Iran, Portugal, and the Philippines urban protestors and military defectors were the key revolutionary actors. Mexico, after its civil war, developed a capitalist, one-party state; Cuba under Castro became a one-party state but of socialist design. In Iran, the broad coalition of socialist workers, liberal professionals, and religious organizations that toppled the Shah gave way to an Islamic, clerical-led republic. In Nicaragua, South Korea, Portugal, and the Philippines, despite strong Marxist influences in the first, an interlude of military rule in the second, and attempted counterrevolutionary coups in the latter two, stable constitutional democracies appear to have emerged.

Although colonial regimes, empires, and dictatorships have been the usual target of revolutions, republican regimes have not been immune. Where civilian governments have been internally divided and ineffective, economic hardships have become severe, and radical nationalist movements have managed to organize coalitions of shopkeepers, small farmers, church and military supporters, radical regimes have not merely overthrown feeble democracies, but--unlike more common military coups--have sought to destroy the constitution and create wholly new institutions of mass mobilization and one-party rule. In three major cases in this century--Italy in 1922 under Mussolini, Germany in 1933 under Hitler, and Spain in 1936 under Franco-rightist regimes set about deliberately dismantling constitutional democracies and creating fascist states. But in other cases, the thrust came from the left. In 1952, tin miners and urban professionals combined to overthrow the oligarchic elite of Bolivia. In 1968, a leftist military regime took power in Peru and attempted to remodel the economic and political foundations of the society. And in 1978, a similarly radical military coup overthrew the republican regime in Afghanistan. In most cases, although the revolutionary regimes aimed at permanent rule they were remarkably short-lived. Italy's and Germany's regimes were successful in remodeling their societies (including in Germany's case a horribly successful genocidal effort to rid the territories under German control of Jews), but they were destroyed in 1945 as a consequence of defeat in WWII. In Bolivia, Peru, and Afghanistan the efforts to remodel society were only partially successful, and ran into severe resistance that the regimes could not overcome. Military coups in Bolivia in 1964 and in Peru in 1975 returned both countries to the previous pattern of alternation of democracy and dictatorship in the context of defense of weak constitutional institutions. Afghanistan'5 radicals were defeated by an Islamic counterrevolution in 1992 despite a massive Soviet invasion in support of the radical regime. Only Franco's regime in Spain lasted a full generation before giving way to democratic reforms.

In short, although the "great revolutions" still command attention, the modern world has witnessed a great many revolutions, against varied kinds of regimes, and with varied results. This immense variety has greatly complicated the task of seeking general principles that underlay revolutions.

Many scholars adopting this view tried to understand why ordinary individuals would join revolts, and thus focused on individual and group psychology. Among the founders of modern social science, Sigmund Freud and Max Weber both argued that the masses were drawn into revolutionary struggles by "charismatic" leaders, who acted as surrogate fathers providing a sense of belonging (Freud), or as surrogate prophets providing a sense of salvation (Weber). Vilfredo Pareto and Gaetano Mosca argued, in a similar vein, that the masses were cajoled or intimidated into revolutionary action by talented men who wanted power; but the masses remained followers, and what occurred in revolutions was a mere circulation of different elites. Alexis de Tocqueville allowed the masses more initiative, arguing that when conditions improved and burdensome social institutions were losing their hold, revolution was most likely, for this was precisely when ordinary people would find the remaining inequalities and oppressive institutions most irksome. Tocqueville thus believed that elites who tried to reform obsolescent institutions helped bring on revolutions, for they taught the masses that current institutions were both mutable and in need of change.

After WWII, more materialist views developed. James Davies and Ted Robert Gurr argued that revolution occurred when the masses felt "relative deprivation," that is, a gap between their expected welfare and their actual condition. Other scholars, probing the nature of rational choice, considered why ordinary individuals might choose to support revolutionaries and concluded that they would not even if they felt deprived, unless they were persuaded by strong offers of potential rewards and bound by strong ties of commitment to communities affected by revolutionary struggles.

The major alternative to "mass" arguments was the class society theory traceable to Karl Marx. In this view, different groups of people had different economic positions: some controlled land, others controlled businesses, some controlled nothing but themselves and their labor. Ordinarily, one class dominated all others, and the political rulers acted on behalf of this class. Revolutions occurred when the leading class was weakened by changes in society's economic organization; members of the subordinate classes would then revolt against the leading class.

This view provided not only an explanation of why revolutions occurred, but a model of history. In Marxist theory history unfolded through a series of revolutions: Feudal rulers and their landed elites would first be overthrown in a series of revolutions led by merchant and manufacturing capitalists (the bourgeoisie); these revolutions would destroy feudalism and usher in an age of capitalist expansion. The English Revolution of 1640 and the French Revolution of 1789 were key examples in Marxist historiography. But Marxism also looked to the future: capitalism itself would fall into crisis from squeezing too much from its workers; the bourgeoisie would then become victims of a worker's revolution aimed at overturning the capitalist system of wage labor and private property, and implementing in its place a socialist economy and minimal state.

Although the mass and class models of revolution have been the most common models for the last two centuries, in recent decades scholars have moved away from these views. They have come to insist that social organization is more complicated than a simple opposition between rulers and ruled. Societies have many different groups, with different levels of status, wealth, and power. Even the "masses" are divided into urban and rural, old and young, industrial and service workers, different regional and ethic groups, and so forth, making it impossible to speak simply of the conditions and likely actions of a "typical" person.

Moreover, despite decades of scholarship concerned with class identity and class consciousness, the history of the proletariat and bourgeoisie, and efforts to relocate the motor of capitalism in international economic trade and exploitation of the developing world, Marxist theories of revolution have fallen into disuse. Their main flaw has been that extensive empirical study of the cardinal cases--the English and French Revolutions--has shown conclusively that they were not class revolutions. Neither the key actors, their supporters, nor their goals, nor the revolutions' outcomes, can be validly attributed to any particular "class."

Social scientists therefore now speak of complicated social "systems," and social "structures," with many interrelated components. They recognize that social systems have a large capacity to tolerate injustice, oppression, and inequality, and still function. To understand why revolutions occur, we need to understand how societies function, and how their various structures cohere or break down.

Systems and Structures

Viewing a society as a system leads us to consider a series of relationships. There are external relationships between the society and its physical environment--the supply of raw materials, population flows, technical production processes, waste disposal. There are external relationships between the society and its economic and political environment--trade relationships, borrowing from and economic dependence on other countries, matters of international defense, and various treaties and foreign aid relationships. And there are internal relationships between different groups within society that have different functions--workers, religious leaders, political leaders, leaders in the creation and distribution of information and entertainment, and economic and business leaders.

Under normal conditions, oppression, injustice, and discontent are scattered throughout the social system and kept in check by the separation and balances among the various groups in the system. Some relationships may be oppressive and create conflict and strain, but others may work more-or-less smoothly. Chalmers Johnson therefore has argued that only if there are multiple dysfunctions in a society--that is, if many of the normal external and internal relationships in society are under stress--is a society likely to have a revolution.

Yet if all societies should be seen as social systems, it remains true that some societies are more stable than others. That is, the particular social structure--the organization of various social groups and their particular relationships--makes a difference. In some societies, the social structure is extremely rigid. In these cases, although the social system may be quite stable as long as its environment is stable, it is difficult for the society to respond to changes in its environment--such as changes in population, or pressures of war, or technological changes in the economy--without suffering multiple dysfunctions that spread throughout the society. In other societies, the social structure is flexible, and various groups have the ability to create changes in leadership and social policy. In these societies--including all modern industrial democracies--changes in the environment can be dealt with through changes in public policy and political alignments, allowing these societies to survive great social stress without suffering a revolution.

Theda Skocpol has shown that the social structures of countries that experienced "great revolutions,"--France under King Louis XVI, Russia under Tsar Nicholas II, and China under Chiang Kai-shek's nationalist regime--had certain features that made them highly vulnerable to revolution. Their royal or imperial governments were financially or militarily weak compared to other states, making them vulnerable to costly wars. Their aristocracies were not in tight control of the countryside, making the control of the peasantry depend on the strength of the (already weak) central government. And finally, the peasantry had autonomous forms of organization to foster collective action against elites; traditional village assemblies in France and Russia, and the Communist Party organization built up in rural China in the 1930s and 1940s. Thus in the event of a war that weakened the state, or conflicts between the state and elites that paralyzed the government, popular uprisings could not be contained. The fiscal crisis and elite rebellions of 1789 in France, the military defeat of Russia in WWI, and the Japanese invasion of China in WWII therefore opened the way for mass revolts.

In contrast, in nineteenth century England and Germany--countries with stronger states, and with aristocracies that were both more in control of the government and more in control of the countryside--the pressures of war and popular unrest led to flexible reform movements carried through by states and elites, rather than to revolutions.

Viewing societies as systems, each with particular social structures, therefore helps us to understand why some countries have experienced revolutions and others have not. Yet there are so many different societies, and different social structures, that we need some further guide to a general understanding of when particular societies seem to be entering revolutionary situations, and why.

A Process Model of Revolution

Revolutions are sometimes for convenience's sake described as if they were a single event, such as the Russian Revolution of 1917, or the Nicaraguan Revolution of 1979. In fact, revolutions are long processes, in which the old government weakens, a struggle for power takes place, and then authority is reestablished by a new government. Although we often identify such processes by the date on which the old government is first attacked, there is more to a revolution than that first assault.

Charles Tilly has argued that a revolution begins when an opposition first undertakes a mobilization of people against the government. He suggests that we need to understand not only why people might rebel, or how certain social structures are vulnerable to revolution. We also need to understand how people go about preparing to act, and how governments react once a revolution is underway.

More recently, Jack Goldstone, with Ted Robert Gurr and Farrokh Moshiri, has examined revolutions from the seventeenth century to the 1980s, and found that certain relationships can be found in cases from the early modern revolutions of Europe to modern revolutions in Nicaragua and Iran.

These scholars have argued that we can recognize when a revolutionary situation has arisen, and how it is likely to unfold, once the characteristic process of revolution is understood. This process model notes that many different combinations of causes and social structures can produce a revolutionary situation. However, whatever the particular causes, revolutions only occur if they produce conflicts at many different levels of society. Only such widespread conflicts can undermine an existing government and lead to radical social change.

We can thus determine whether potential causes of revolutionary conflict--e.g. international pressures, economic changes, population shifts, corruption, religious conflicts, fiscal crises, etc.--are likely to produce a revolution in a particular society by assessing the following trends: the level of popular grievances and their potential for mobilization; the degree of elite conflicts; and the extent of state weakness. In addition, attention to the process of revolution requires that we consider the roles of international forces, revolutionary coalitions, ideology and nationalism, war and state terror, and the outcomes of revolution.

Popular Grievances and Mobilization. A revolution requires supporting forces, whether they are urban crowds that attack officials and riot and demonstrate, or peasants who attack landlords and protect rural guerrillas, or soldiers in revolutionary armies who create and defend the revolution. Popular groups thus need a motive to participate in revolution.

Yet it is an odd paradox of history that popular groups who participate in revolutions are generally not interested in revolution per se. Instead, they are interested in correcting specific grievances. The peasants whose riots in the French countryside supported the French Revolution simply wanted more land at lower cost--they did n6t care if it was the King or the Revolutionary Assembly who abolished the landlords' rights to extract extra payments and fees. The cowboys and farmers who supported Emiho Zapata's and Pancho Villa's revolutionary armies in the Mexican revolution simply wanted protection from business speculators who were trying to take over their land. The urban demonstrators who supported the Ayatollah against the Shah of Iran wanted a more Islamic, more genuinely Iranian society, where the virtue of their daughters and the income of their families would not be constantly threatened by foreign business dealers, corrupt speculators, and Western modernizers. If the Shah would not protect them, they would turn to someone who would.

Popular grievances at the outset of revolutionary situations are thus often simply a demand that traditional rights, livelihoods, and virtues be protected. These demands do not come from the poorest of the poor --vagabonds, criminals, and the destitute play virtually no role in revolutionary crowds. Instead, demands for change come from individuals who have incomes, and modest means, which they are in danger of losing.

These dangers usually come from two major sources. One is population growth, which in traditional societies can overburden farmland, labor markets, and food supplies, leading to the decay of traditional routines and livelihoods. The other major source is rapid economic development, which--although in many cases it brings social and economic improvement--can sometimes lead to a decay of traditional livelihoods before people can adapt and find new industrial and service jobs. In particular, if economic development is managed by a corrupt government, in such a way that its benefits come mainly to a small elite group while the pains of adjustment are widespread, economic development can lead to great popular grievances.

Yet if popular grievances in revolutionary situations are mainly about particular threats to traditional incomes and livelihoods, or violations of traditional rights, how are these grievances assembled and directed toward revolution? Grievances will not move people to action unless people have means to discuss, plan, and act on those grievances together, with confidence that collective action will gain them some result. Thus rising grievances must be coupled to significant potential for collective action.

Collective action is facilitated when individuals belong to communities whose members are accustomed to discussing common issues and acting jointly to solve them. These need not be formal organizations or even revolutionary parties. They may be neighborhood groups, workplace organizations, religious congregations, schools or universities, or peasant villages. Revolutionary actors usually recruit through, and base their solidarity on, some such organizations.

In addition, the "space" for individuals to discuss and take action is increased in settings where individuals are not under close supervision of landlords or state officers. Autonomous peasant villages, frontier regions, and great urban concentrations offer privileged settings for mobilization. Internal migration--to frontier areas or cities--thus offers increased opportunities for mobilization to occur.

Finally, it should be noted that many revolutions have occurred during periods with unusually large youth cohorts in the population. The recklessness and idealism of youth can thus also be a factor in revolutionary mobilization.

In sum, popular action in revolutions is likely only where there is a high potential for mass mobilization, drawing on a combination of pressing grievances, existing networks, population concentration in locales favorable to mobilization, and the fervor of youth.

However, popular actions alone cannot create either a coordinated national movement or a new revolutionary regime. For these to develop, popular grievances must combine with actions by elites.

Elite Conflicts. It is another paradox of revolutions that they are led by elites--that is, by individuals and groups who have considerable status and power in the existing social system. The French Revolution was led by nobles who turned against the King; the Iranian Revolution was led by religious and merchant leaders who turned against the Shah; the Nicaraguan Revolution was led by sons and daughters of the economic elites, and supported by business leaders. This is not to say that in a revolution all elites turn against the regime. Rather, in a revolutionary situation, certain elite groups and individuals come into conflict with the government. They then seek support by mobilizing popular groups which, as noted above, have grievances of their own. This coalition of revolutionary elites and popular supporters then struggles for power against the government.

Why would elites turn against the existing arrangements that support their privileged positions? The answer lies in examining the relationships of particular elite groups--to the state, to other elites, and to the populace. In a stable society, elites are supported by the government and give their support to it. Elites compete for power and status, but not to the degree of destroying each other. And elites draw income and status from the populace--either directly through rents and taxes, or indirectly through profits from asset ownership or control of important offices--while providing in return certain services for the populace, including government, legal protection, and support in times of difficulty.

When these various relationships become disrupted, however, elites can become divided, competitive, and come into conflict with the state and with other elite groups. If the state attacks elite privileges or wealth to expand the government's own power; if the elites find that opportunities for status and wealth are shrinking, so that they or their children might lose their positions; if popular poverty and disorder make it difficult for elites to draw revenues from the population; many elites are likely to conclude that a new government, perhaps even a new system of government, is necessary.

There are many potential sources of disruption of elite relationships: a changing international economy or military involvement that threatens the income or position of elites; a growing population or faltering economy that creates widespread scarcity, and hence reduces the profits and goods to be divided among elites; changes in the domestic economy, or corruption of government, that weakens or eliminates traditional elite positions; or the arrival of new claimants to elite positions from ethnic or economic groups who previously had little wealth or status but have acquired wealth and now demand inclusion in the society's elite ranks.

In a flexible society, with widespread elite participation in the political system and free movement of individuals into and out of elite groups, such conflicts are unlikely to grow. Elite groups will be able to carry through changes in state policy, form coalitions with other elites and popular groups, and create reforms to resolve such conflicts. However, in a society with a rigid state that excludes many elites from power--such as a traditional monarchy or a modern personal dictatorship--such conflicts may fester and grow. Thus it is not only the range of elite conflicts, but the ability of the state and elites to peacefully resolve those conflicts, that determines the likelihood of revolution.

State Weakness. States, in order to rule society, require two things. First, they need sufficient money, raised by taxation or control of companies or raw materials (e.g., oil). Second, they need sufficient political support--from bureaucrats, military leaders, businessmen, other elite groups, and the populace in general--to have their orders carried out at least willingly, if not enthusiastically. To some degree, strength in one area may compensate for weakness in the other. That is, if the state lacks money but has political support, it may be able to gain approval for new policies to raise revenues. And, if the state has a large independent income, it may be able to hire soldiers and police to help enforce the carrying out of state policies. But to some degree, both needs remain important. A state cannot function if bankrupt; and even a rich state cannot survive if no one will obey it. Thus a state may be strong (high in resources and political support) or weak (low in both categories), or moderately weak--that is, strong in one respect and weak in the other.

A strong state can muddle through a considerable period of popular grievances and limited elite opposition. With adequate funds and political support, there is room for compromise and reform. However, if a state is weak, popular unrest or elite opposition may lead to conflicts that it cannot resolve without compromising its own existence. In such weak states, conflicts between the state and other groups can escalate and lead to revolution.

Two kinds of state that are moderately weak are traditional monarchies-such as the kingdoms of early modern England and France or the imperial governments of Russia and China--and modern personal dictatorships--such as those of the former Shah of Iran, or Ferdinand Marcos in the Philippines. Traditional monarchies are often politically strong, because the long tradition of hereditary kingship commands much popular and elite respect. However, they are often economically weak, because traditional tax systems are generally rigid and incapable of responding to changes in the population and the economy. Thus monarchies and empires often become vulnerable to revolt when they stop expanding and their revenues freeze or decline, while their populations continue to grow. If this economic weakness combines with a loss in war, or a growth in corruption, or religious conflicts that lead to a loss of political support, then a traditional kingdom or empire can be fatally weakened and open to revolution.

Personal dictatorships are often economically strong, through control of foreign aid or control of companies and resources that provide the state with revenues. However, they are generally politically weak, because they exclude from economic and political power everyone but the dictator and a small circle of cronies. In such states, the government may seem powerful as long as it is economically strong enough to manage the economy well, generously reward supporters, and punish adversaries. However, if a change in the international or domestic economy, or in international support, leads to a decline in state resources, or if the state is greatly strained by borrowing and excessive spending, the state may dramatically weaken. Opponents of the state may then speak up and demand a change. The state may respond by seeking to confiscate more wealth from elites and the population or by attacking its critics. Often, these measures do not strengthen the government but leave the dictator isolated and widely hated. Precisely these conditions led to revolutions in Iran, Nicaragua, and the Philippines.

In the 1980s, Communist states in Eastern Europe and the Soviet Union also developed both kinds of weakness--the rigidities and dismal performance of their economies led to financial weakness, while the closed governments that excluded everyone except Communist party leaders from economic and political power, led to loss of political support. These states thus grew vulnerable to revolution towards the end of the decade.

In Communist China, on the other hand, agricultural and trade reforms led to excellent economic performance (growth rates of almost 10% per year in GNP in the 1980s). This strong economic performance gave the state both economic strength and political support. Although the exclusion from power of Chinese who are not Party members, and a period of high inflation in the cities, led to protests by students and workers in 1989, China's government was then strong enough to stamp out most opposition. However, the Party has lost ideological support as socialism has been set aside, and economic growth may not continue at this rate forever. lf economic growth should falter, or the regime is unable to maintain financial strength to counter its closed and ideologically weakened political structure, China's communist regime too could be vulnerable to revolutionary change.

International Pressures. The relationships among the general population, elites, and states do not develop in a sealed environment. Forces outside of national borders often affect domestic politics. Foreign economic or military aid may prop up a weak government, international economic conditions may affect national growth and state revenues, and direct foreign intervention may seek to support a government or to topple it. For example, Soviet intervention in Eastern Europe crushed attempted revolutions in Hungary in 1956 and in Czechoslovakia in 1968. But when Soviet leader Mikhail Gorbachev reduced Soviet influence in Eastern Europe in 1989, widespread revolutions occurred.

Coalitions and Conflict. We have already noted that in a revolutionary situation, different social groups may oppose the government for different reasons. Societies have many different elite groups--political, economic, and religious--and different popular groups--urban, rural, and people from different regions or ethnic groups. Some elites may oppose the government because it excludes them from power; others may object to government corruption or incompetence; some may be angered by a lack of opportunities for gaining wealth and status for themselves or their families; others may object to foreign influence or dependence. Popular groups tend to have more traditional concerns--peasants threatened with loss of their land, urban workers threatened with loss of their jobs or excessively high costs of feeding their families. Both elites and popular groups may be threatened by government actions that violate traditional cultural or religious principles, or elevate one regional or ethnic group above others. Once demonstrations or revolts have begun, government repression, if it is too widespread or erratic, may drive elite and popular groups into the ranks of the opposition.

If these diverse groups are to create a revolution, rather than be turned against each other and suppressed by the government, they must find some principle for cooperation, some means of building a coalition against the state. Such a cross-class coalition, including a variety of popular and elite groups, is the key to successful revolutions.

In the early phases of a revolution, such a coalition is usually led by moderate reformers (since most extreme radicals are either in jail, in exile, or in hiding.) However, as the revolution progresses, this coalition must face a variety of conflicts. First, the coalition must fight against the government and forces seeking a counterrevolution. Second, once the old government is defeated, the coalition often undergoes internal conflicts over how extreme the revolution should be. These conflicts generally lead to changes in revolutionary ideology, and then to state terror and war.

In particular, the revolutionary coalition often fragments, with different factions competing for popular support and state power. In such cases, civil war and revolutionary violence may be greater after the fall of the old regime than in the events leading up to its collapse. The French revolutionaries' campaigns against moderate groups in western and southern France, Stalin's campaign against the peasantry, Mao's cultural revolution against moderate bureaucrats and pragmatists in China, and the Iranian clerics' campaign against western liberals were comparable to or greater, in their intensity, than the campaigns that brought revolutionaries to power. In such clashes, ideological and physical conflicts may escalate, reshaping revolutionary politics among more radical lines.

Ideology and Nationalism. Revolutionaries at first need a broad, overarching set of ideas that will unite the opponents of the government. A simple set of ideas that seems to promise something for everyone is the usual result. Slogans such as creating democracy," or "forging an Islamic Republic" promise much and do not demand detailed explanation.

However, as revolutionary struggles against counterrevolutionaries continue, revolutionary leaders need a stronger ideology, one which will inspire sacrifice and deeper bonding among supporters. Such an ideology usually takes the form of extreme nationalism, an "us against them" attitude, in which revolutionaries and their supporters claim to be the true defenders of the virtue of their country, while all counterrevolutionaries are branded as enemies and traitors.

In the beginning stages of revolutions, therefore, one generally finds a broad coalition proclaiming moderate goals to satisfy everyone. But as the struggle for power develops, moderate goals seem less satisfying. More extreme leaders, with a stronger, more radical ideology, often come to the fore. They claim the mantle of true defenders of the revolution and the nation. And they attack everyone who opposes that claim.

The ideology of revolutionary leaders also profoundly shapes the institutions of the post-revolutionary state. Enlightenment-inspired revolutionaries sought to create constitutional regimes that promoted individual enterprise and limited state power; Marx and Lenin-inspired revolutionaries, in contrast, sought to create one-party states that tolerated little dissent and directed the economy. Revolutionary leaders' religious beliefs--whether fundamentalist (as among English Puritans and Iranian clerics) or secular (as in France, Russia, and China)--have governed religious organization and practice. Adherence to capitalism or socialism has determined the degree of revolutionary states' efforts to redistribute property and income. And post-revolutionary democracies have only emerged--as in the Philippines and Nicaragua--where the revolutionary leadership was firmly committed to democracy as a major goal.

Finally, it should be noted that broad cultural frameworks constrain or promote revolutionary change. Where cultural frameworks are available that view history as progressive, particularly if they stress the purification of earthly society as a sign or requisite of a future divine triumph, revolutionary leaders are likely to use these ideas to promote and justify a thorough remaking of society. Protestant theology, and its secular offshoots of rational liberalism and Marxism, have thus been extremely favorable frameworks for revolutionary change, and their spread has often paved the way for revolution. On the other hand, in cultural frameworks that view history as cyclical, or view earthly change as irrelevant to spiritual victories (as did conservative Catholicism, and most classic and East Asian religions), the urge to radical social transformation is likely to be muted. Where only such frameworks are available, even in the event of political crises and state breakdown, elites are more likely to seek a revival of traditional institutions than to attempt a remaking of society.

War and State Terror. It is yet another paradox of history that revolutions, which are generally intended to relieve suffering by acting on the grievances of various popular and elite groups, instead often bring great suffering and loss. When revolutionaries fight for power, they need to engage in all-out war. First, they need to fight the old government and its allies. When the counterrevolutionaries are mostly within their country, they may engage in civil war. And when foreign countries seek to turn back the revolution, international war results. Most revolutions, including those in Iran, Nicaragua, and Vietnam, led to both civil and international wars, with hundreds of thousands of casualties.

In addition, revolutionary coalitions often split apart when trying to decide on how far to. go in prosecuting a war, in destroying the old government, or in redistributing property and power. Then moderates and more extreme radicals end up fighting; and since the radicals are usually better at mobilizing popular support, the radicals often gain a period in power, in which they terrorize their opponents.

During the period of state terror, the new government leads a search for enemies, and attempts to purge them from society. The search whips up popular enthusiasm and often disregards legal niceties. The overriding aim is to purify society. The period of terror may be brief, may last for years, or may recur at intervals. State terror may involve informers or secret police, show trials, executions, long prison sentences, or exile and re-education camps for any act of opposition to the state. Notable periods of state terror occurred in the French, Russian, Chinese, Cambodian, and Iranian revolutions, with somewhat more modest state coercion in the Vietnamese, Cuban, Mexican, Afghan, and Iraqi revolutionary regimes.

Revolutionaries often justify the costs of terror and war as necessary sacrifices to achieve revolutionary outcomes. However, revolutions have in fact produced rather mixed and often disappointing results.

Outcomes

The outcomes of revolutions involve changes in institutions, attitudes, geopolitical relationships, and economic organization. Although revolutionary outcomes vary in the degree and effectiveness of change they produce, a few generalizations are possible.

Stronger Government Authority. Revolutions occur when weak governments are unable to respond to the grievances of the population and elites and unable to defend themselves against attacks by opponents. Revolutionaries are therefore generally aware of the need to strengthen the government in order to avoid being overthrown in turn. Revolutionaries usually seize resources and increase taxation, and greatly expand the size of government. They often seize land and other assets from the rich, and either administer or redistribute these assets to gain popular support. Revolutionaries also often abolish unpopular dues, obligations, or old elite privileges. In addition, revolutionaries spend considerable effort in spreading a strongly motivating nationalist ideology. For all these reasons, they can--once they have established power--generally count on widespread popular support. New revolutionary governments thus tend to be stronger, both economically and in terms of political support, than the governments they replaced. Since revolutionary governments excel at mobilizing their populations for war to defend the revolution, new revolutionary states also tend to be much more formidable and aggressive military powers than before.

National Pride. Although it is perhaps intangible, the most common and significant outcome of revolution is to fill the citizens of the new revolutionary state with great pride in their independence and self-determination. A sense of standing up to other countries, and to bad leaders, and of seizing one's destiny makes revolutionary periods deeply exciting and meaningful to those involved. This national pride can sustain a revolutionary government long after it has begun to run into other economic or political difficulties, as in contemporary Cuba and Vietnam. On the other hand, the lack of national pride in the Communist governments in Eastern Europe, which were imposed by Russia after World War II, helped pave the way for revolutions in those countries once those governments grew weak. In addition, where new regimes (whether achieved by revolution or other means) fail to create a sense of national identity, state weakness can create openings for the assertion of alternative identities, and sharp conflicts between different groups, as occurred following the collapse of Yugoslavia.

Problems of Economic Growth and Inequality. Revolutions have, unfortunately, been unable to simultaneously solve the problems of providing economic growth and reducing inequality. Revolutions that led to capitalist societies--such as the American Revolution of 1776, the French Revolution of 1789, and the Mexican Revolution of 1911--have allowed room for enterprising individuals to produce and accumulate great wealth and have achieved considerable economic growth. However, they have also allowed considerable inequality and even great poverty--sometimes greater than in the pre revolutionary society--to develop.

Revolutions that have led to socialist societies--such as the Russian Revolution of 1917, the Chinese Revolution of 1949, and the Cuban Revolution of 1958--have done rather better at increasing equality and eliminating extreme poverty. Though all revolutions tend to involve some redistribution of land or income, such redistribution's have been more thorough and long-lasting in socialist societies. And socialist revolutionary societies have excelled at spreading literacy and improving access to medical care. However, socialist societies have also choked individual efforts to be enterprising, and their heavy regulation of the economy has tended to stifle flexibility, innovation, and overall growth. Thus socialist societies, though they may show rapid initial economic growth, tend to reach a plateau where they stagnate. As their population grows and capitalist societies pass them by, socialist societies tend to provide a more equal, but increasingly less satisfying, economic life for their people. At that point, the government's own economic resources, and its political support, may decline, thus greatly weakening the state. This process left the governments of the Soviet Union and Eastern Europe vulnerable to revolution in 1989-1991.

Difficulties of Democracy. Revolutions generally promise greater democracy and equal rights for all, including ethnic and religious minorities and women. However, democracy often falls victim to the strains of fighting against counterrevolutionary forces. War and terror require tight central control and lead to militarization of society. The search for counterrevolutionary enemies tends to shepherd people into a single, revolutionary party. Thus revolutions commonly lead to dictatorships or one-party states, with at best limited protection, and often persecution, for minority groups who lie outside the aggressive nationalist ideology of the revolutionary government. The persecution of Tibetans in China, of Kurds in Iran, and of Native Americans in Nicaragua are but a few examples of ethnic persecution in new revolutionary states. Moreover, where women's rights have long been neglected, revolutions led by men--despite good intentions--are unlikely to greatly change the condition of women.

Democracy is only likely to emerge in post revolutionary societies that do not face strong internal counterrevolutionary threats, or after such threats have been defeated, and where the revolutionary leadership is firmly committed to democracy. India, the Philippines, Portugal, Nicaragua, and the United States are among the few cases of nations that have become stable democracies following revolutions. However, after several decades, as large professional and middle classes emerge, even a one-party revolutionary state may face renewed calls for pluralist democracy, which were suppressed when the state first consolidated its power. This has been the case in Mexico, China, the former Soviet Union, and Eastern Europe.

Mass theories and class theories of revolution are too simple to account for this variation and complexity. A process model that pays attention to changes in the structures of and relationships among states, elites, and popular groups, and to the roles of revolutionary coalitions, international pressures, and ideologies, is more useful.

Revolutions occur in countries that are facing the pressures of international conflict or population growth with weak states, contentious and divided elites, and populations whose grievances and mobilization potential are high. As long as such conditions occur--and there are still prospects of such conditions developing in many parts of Africa, the Middle East, Latin America, Asia, and even China--the history of revolutions will not be over.

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