Most historians cringe at talk of the "lessons of history." Trained as specialists and wary of sweeping comparisons, they flinch from attempts to make past events speak directly to current policy. They remind us of what makes circumstances unique, highlighting differences where others see similarities.

Politicians and policymakers, on the other hand, have few compunctions about drawing on historical analogies to frame and explain policy choices. Scholars may wince at their shallow thinking and imprecision, but such practitioners always have the last word. And even if we try to understand our world purely in its own terms, implicit, historically grounded beliefs -- in trends and turning points, analogies and metaphors, parallels and lessons -- inevitably shape our views. Better, then, to ask explicitly how history should inform our understanding of the present.

The historical analogy making the rounds of late is the notion that the United States today is an empire that can and should be compared with imperial powers of the past. This idea gained immediacy when U.S. soldiers trod in the footsteps of Alexander the Great in Afghanistan and U.S. tanks rumbled through the ancient imperial heartland of Mesopotamia: ruling and remaking distant, recalcitrant peoples looks very much like an imperial project.

Casual talk of a Pax Americana -- harking back to the Pax Britannica, itself an echo of the Pax Romana -- implies that the United States is following a pattern of imperial dominance that holds precedents and lessons. The metaphor of empire merits neither angry rejection nor gleeful embrace. It instead deserves careful scrutiny, because imperial history contains analogies and parallels that bear critically on the current U.S. predicament.


An empire is a multinational or multiethnic state that extends its influence through formal and informal control of other polities. The Indian writer Nirad Chaudhuri put it well: "There is no empire without a conglomeration of linguistically, racially, and culturally different nationalities and the hegemony of one of them over the rest. The heterogeneity and the domination are of the very essence of imperial relations. An empire is hierarchical. There may be in it, and has been, full or partial freedom for individuals or groups to rise from one level to another; but this has not modified the stepped and stratified structure of the organization."

Most people throughout history have lived under imperial rule. The current international system, with nearly two hundred independent states and not a single confessed empire, is a historical anomaly. Most empires, however, have had only regional scope and limited ambitions. In the nineteenth century, the French, Russian, Turkish, and Austro-Hungarian Empires jostled one another at the margins and waged war in conjunction with other allies, but none towered over the rest. Of past empires, only ancient Rome and the British Empire in the nineteenth century had enough power and influence to dominate the international system. Each exerted not only military strength, but also cultural influence; each made international economic order possible; each was envied, resented, and ultimately displaced -- not by a single foe but by a combination of enemies abroad and weaknesses within.

How does the United States compare with Britain and Rome? Start with the reserve currency of empire: military strength. Rome's legions hacked their way to world power, suffering a series of military disasters in the process: Gauls, Greeks, Carthaginians, Persians, and numerous barbarian bands inflicted on Roman forces defeats of a kind that U.S. troops have not suffered since the early days of the Korean War. The legions shed their blood in internecine warfare, clashes among rival dictators, and massive revolts by humiliated clients and mutinous subjects -- ills without contemporary American parallel. Rome recruited many of its soldiers from conquered lands. These soldiers owed allegiance chiefly to their own leaders and fellow troops, not to a government, constitution, or homeland. Thus, although Rome dominated its world, it did so with none of the assurance or domestic solidity of the United States.

The British army, meanwhile, relied on pluck, not numbers. Its force was negligible compared with the great conscript armies of continental Europe; Bismarck once scoffed that if the British were to land their army on the Baltic coast, he would send the Berlin police force to arrest it. From 1815 to 1914, the British Empire essentially withdrew from the game of continental warfare, a fact that British statesmen recognized as a restraint on their behavior. As for the Royal Navy, it ruled the seas but teetered constantly on the verge of technological obsolescence and (as it believed) overall inferiority. The French introduced ironclad warships before the British did, and even when the British made a breakthrough -- as with the Dreadnought class big-gun battleships -- it was with the knowledge that their technological rivals, Germany and the United States, would soon follow suit.

U.S. military power is of a different order entirely. The United States now accounts for between 40 and 50 percent of global defense spending, more than double the total spending of its European allies (whose budgets are so riddled with inefficiencies that, aside from territorial defense, peacekeeping, and some niche capabilities, the European pillar of NATO is militarily irrelevant). In virtually every sphere of warfare, the United States dominates, an unprecedented phenomenon in military history. On and above the earth and on and below the sea, U.S. military technology far surpasses that of any potential opponent. No other power has the ability to move large and sophisticated forces around the globe; to coordinate and direct its own forces and those of its allies; to keep troops equipped, fed, and healthy; and to support those troops with precision firepower and unsurpassed amounts of information and intelligence.

Viewed from within, of course, the picture looks very different. U.S. soldiers know all too well their own deficiencies and vulnerabilities: they grouse about aging trucks, jammed rifles, and intermittent data links. Viewed from the outside, however, the world has seen nothing like the U.S. military. British infantrymen in 1900 shot more accurately than their continental European counterparts but did not differ all that much from them in terms of equipment and unit skills (and the Tommies found themselves inferior to Boer citizen-soldiers equipped with German-made rifles). Today, an average U.S. battalion has better kit -- from body armor to night vision devices -- than any comparable unit in the world; with a few exceptions (mostly allies of the United States), it trains more effectively in the field; and it has officers and sergeants groomed by a military schooling system more thorough than any in history.

This qualitative advantage looms even larger at the higher levels of the armed forces. No other military has the B-2 bombers or the satellite constellation, the aircraft carriers or the long-range unmanned aircraft of the U.S. Navy and Air Force. No other country is remotely close to having the resources afforded by a $400 billion defense budget or the accumulated military-industrial capital of years of spending on construction and infrastructure. No other research establishment can match that of the United States, which receives more money than the entire defense budget of its largest European ally.

Put thus, U.S. military power seems to invite hubris. But again, viewed from within the picture appears different. Generals and admirals fret over forces stretched too thin, anticipate threats from unconventional and irregular opponents who will avoid U.S. strengths and seek out weaknesses, and worry that their political masters will succumb to the intoxication of great power or their fellow citizens will fail to understand the commitment of money and blood that any war requires. Such leaders understand better than their civilian superiors the fragility of great military strength. But that does not undermine the basic fact of U.S. predominance. Augustus lost his legions in the Teutoburger Wald, Disraeli his regiments at Isandhlwana -- in both cases, succumbing to primitive opponents inferior in weaponry and, according to the imperial powers, culture as well. Not even in Vietnam, where the odds of such a debacle's occurring were highest, did U.S. forces suffer a similar defeat. Today, the legions of the United States have no match, and the gap between them and other militaries is only growing.

No empire, of course, can sustain itself by raw military power alone. It requires, at the very minimum, sufficient resources to generate power. Here, too, the contrasts between the United States and its imperial predecessors are striking. Rome was a city, Britain a set of moderately sized islands on the periphery of Eurasia. The United States spans a vast, rich continent. In the middle of the nineteenth century, the United Kingdom's population numbered only slightly more than half that of France and considerably less than those of the rising powers -- Germany, the United States, and Russia. Its once-impressive economic lead over the rest of Europe had dwindled everywhere but in the area of finance. By the end of the century, it had fallen behind Germany in the production of steel and electrical power. The United States, in contrast, is the third most populous country on the planet and, unlike most developed countries, has a birth rate at or near replacement rate. It accounts for just under a third of the world's economic production. It does not not live off plunder or accumulated finance or the farming of large estates. Its economy remains the largest, most productive, and most dynamic on the planet.

The might of Rome and Britain depended on ideas as much as on power or resources: imperial power resided in science, literature, and education. Gauls learned Latin, and Indians learned English. Yet the United States can claim greater influence in the realm of ideas as well. In the ancient world, Greek was the language of philosophy; in the nineteenth and early twentieth centuries, German was the language of science. Today, English is the lingua franca of the planet for everything from air traffic control to entertainment. U.S. universities dominate in higher education, while low- and middle-brow American culture floods a planet that simultaneously loathes and embraces Spielberg, Starbucks, and MTV. American music, food, idiom, work styles, and manners are inescapable.


And yet, can the United States be an empire? Raymond Aron famously called the United States "the imperial republic," but even that title sits uncomfortably with Americans. On the whole, the United States has proven itself reluctant to exercise prolonged formal control over states or peoples who do not have the option of becoming its citizens. A country whose sacred texts begin "We the people" and talk of "inalienable rights," which celebrates self-government and legal equality, can never comfortably enjoy imperial rule as traditionally understood. And indeed, even the United States' most overtly imperial endeavor -- rule over Cuba and the Philippines following the Spanish-American War -- generated internal opposition and ended in a remarkably swift, self-imposed retreat.

A longer historical perspective, moreover, suggests that democracy and empire are ultimately incompatible. The tragedy of Athens in Thucydides' Peloponnesian War lies in democracy's difficulty in withstanding the pressures of imperial necessity, compulsions that corrupt and even destroy the freedoms at the root of democracy. The British empire could liberalize domestically and exert dominion externally only so long as Britons believed their subjects to be inferior, childlike, or incapable of self-government, a prejudice undermined by the spread of democratic principles. Whether or not one agrees with the current U.S. attempt to create a democratic Iraq, no one dares suggest (at least not publicly) that Iraqis are, by virtue of history, culture, faith, or race, incapable of ruling themselves.

When the United Kingdom granted independence to the Irish Republic after World War I, it acknowledged the fundamental principle of self-determination -- a concession, some observers have noted, that spelled the end of the British empire and perhaps of all European empires. In the twentieth century, three waves of disintegration -- the first induced by nationalism and World War I, the second by World War II, the third by the collapse of the Soviet Union -- brought an end to the empires that had dominated the three previous centuries: the Austro-Hungarian, Turkish, British, French, Dutch, Portuguese, and Russian.

To be sure, influence and even a few possessions linger, and the imperial era left a strong legacy in everything from institutions and attitudes to street names and school systems. And some forms of imperial rule persist. What is the European and U.S. presence in Yugoslavia, for example, if not a kind of neocolonialism? Dour white men may no longer raise flags and color overseas possessions in red on their maps, but that hardly changes the reality of hierarchy and subordination in international politics. American claims of benign intentions to spread democracy are surely no less and no more sincere than the missions civilisatrices of imperial powers in the past.

But the basic fact remains: empires have dissolved, and they will not return. To talk about the United States as an empire is, from this point of view, to engage in useless and potentially dangerous anachronism, a temptation to hubris, overstretch, and disregard of the claims of the international community.

In the end, however, the applicability of a particular term (debates about empire tend to degenerate into semantic squabbles) does not matter. The fact of the overwhelming power of the United States does. No potential adversary comes close to it, and, for the moment, there is no question of a countervailing coalition to block, let alone replace, it. Its roots lie in a growing and extraordinarily productive population, a stable political system, and a military that is unsurpassable in the foreseeable future. And the United States will not, as some hope and others fear, bind itself to an international institutional and legal order that will domesticate and restrain it. If nothing else, domestic politics would prohibit it. No U.S. leader in the next decade or two will call for a dramatic reduction in defense spending or deny that this country must be the strongest in the world, ready to exert its power globally and act unilaterally if necessary.

The "Age of Empire" may indeed have ended, then, but an age of American hegemony has begun. And regardless of what one calls it or how long it will last, U.S. statesmen today cannot ignore the lessons and analogies of imperial history.


The logic of the Cold War was one of ideological struggle and bipolar contest. The logic of contemporary international politics is that of predominance and its discontents. The first lesson of imperial history is that the absence of rivals does not diminish the challenges for statesmen. Indeed, to crawl inside the heads of British statesmen in the nineteenth century (or, more imaginatively, of Roman leaders during the republic and early empire) is to find leaders weighted down by anxieties.

One overwhelming problem results from the sheer scope of imperial politics. In virtually any government, a handful of people make the critical decisions on foreign and security policy. The larger the empire, the less likely that this small group will know what it must about the nature and extent of imperial problems. Leaders face an unattractive set of options: mastering the challenges of one segment of their political universe while scanting others; dealing with all problems superficially; or devolving large areas of policy to proconsuls and viceroys.

The imperial power faces another fundamental disadvantage in its contests with smaller states or political movements: its leaders cannot focus in the way their opponents can. Smaller actors who recognize this can manipulate an imperial center's politics. Both the Indian National Congress and the Irish Republican Army contained astute students of British politics who knew how to wrestle with a metropolitan government that only intermittently concentrated its attention on the problems of India or Ireland. The stumbles and follies of U.S. foreign policy result in part from a similar problem: its demands simply exceed the capacity of the handful of men and women who manage them. The U.S. decision-making elite, moreover, has none of the social uniformity and cohesion of the Roman Senate (with its ladder of political-military-religious advancement, intermarriage, and adoption) or the British upper class (with its network of universities, clubs, country houses, and regiments). The openness of the American elite may make it more dynamic, but it also makes it harder to lead.

The universal enmity that hegemonic power breeds presents another, and perhaps graver, challenge to imperial statesmen. Empires have no peers and precious few friends. Indeed, to the imperial mind, "friendship" means a relationship in which clients render services and patrons provide protection. The result, as Great Britain found out at least twice during its heyday (first during the American Revolution, when the European powers turned against a global empire forged during the Seven Years' War, then in the Boer War, when European sympathy went exclusively to the unruly British subjects), is diplomatic and military isolation. An empire's opponent always looks like the underdog, the imperial power always the bully. The victories of insurgents become inspiring tales of audacity and sacrifice, the triumphs of legions the inevitable consequence of superior technology, training, and numbers. The empire's claims to act for the good of the international system will always be dismissed (often rightly) as the mere exercise of self-interest. (In moments of reflection, the more honest imperialists confess as much: Rome introduced the Britons to Latin, togas, arcades, baths, and banquets, of which Tacitus remarked, "The unsuspecting Britons spoke of such novelties as civilization, when in fact they were only a feature of their enslavement.")

The inevitability of anti-imperial sentiment may help explain the tide of anti-Americanism that has swept much of the world since September 11, 2001. Some of that antipathy surely emerged in reaction to the personality of an assertive U.S. president whose manner and core beliefs aggravate the elites of Europe and the Middle East. Some surely results from understandable apprehension about U.S. courses of action, in the Middle East especially. But some also stems from the swirl of hostility to the colossus, to all it embodies, and, indeed, to the very fact of its existence. The consequences of that hostility may be managed and mitigated in the years ahead, but some level of antipathy will remain, perhaps grow, and conceivably become dangerous. To be an empire, or something like an empire, is to be envied, resented, suspected, mistrusted, and, often enough, hated.


From imperial problems arise maxims of imperial policy. Few outside of university classics departments read the major Greek and Roman historians today, but their works still have much to offer. The ancient world considered Rome's success both a marvel and a puzzle: the Romans seemed to lack a deep culture, wise statesmen, and invariably successful armies, yet they managed to conquer their world and keep it. The ancients wondered how they did it, and so too did political philosophers of the Renaissance and the Enlightenment, such as Machiavelli and Montesquieu.

Polybius and many who followed him sought an explanation in the role of the Senate, a body that, although internally divided, provided a degree of steadiness to otherwise turbulent policy. Underlying the turmoil of Roman politics, these authors claimed, was a consistent imperial style that persisted despite the rise and fall of consuls and dictators. That style had some simple rules. "Above all, their constant maxim was to divide," Montesquieu observed, and it is such a simple guide to conduct in foreign affairs that its importance is easily overlooked. It was no accident that Rome never faced a coalition of the many powers and peoples that opposed it. Rome's rise was neither foreordained nor without perils: it faced more numerous enemies, more wily commanders, and more ferocious warriors than it had at its command. It picked its fights, however, and took care not to take on the great powers of the world all at once or to allow unified powers to arise against it -- a piece of wisdom that, two millennia later, imperial Germany failed to learn. In 2003, the United States stumbled into similar wisdom when, after decades of benign indifference to the formation of a European Union under Franco-German direction, it realized the merits of siding with the weaker factions inside the EU. (It turned out, however, to be inept in its conduct of a policy that Roman statesmen would have found trivial.)

Reflecting on the practices of the Romans as described by Livy, Machiavelli noted, "One of the great prudences men use is to abstain from menacing or injuring anyone with words." Roman statesmen did not generally bluster or fume. They did not threaten or menace. Instead, they made requests and promises and followed through on both. When the simply clad Roman senator Gaius Popilius Laenas delivered Rome's demand that Antiochus IV withdraw from Egypt, he did not threaten the Syrian king. Rather, he walked over to the problematic monarch and with his staff drew a circle around him in the sand, insisting on an answer to the Senate before Antiochus stepped out of it. The Seleucid king turned pale and acceded, and this act of submission destroyed his reputation in his own luxurious court.

Great Britain, too, made an art of imperial understatement. Throughout the nineteenth century, its leaders assiduously sought to prevent a grand coalition from rising against it, even if that meant accommodating U.S. or Japanese claims. U.S. statesmen today might similarly benefit from maintaining a discreet silence and avoiding offense until absolutely necessary. In retrospect, for example, the brusque manner of the Bush administration's rejection of the Kyoto Protocol, the International Criminal Court, and other measures dear to European hearts created a climate of opinion that made the prewar crisis over Iraq much worse than it need have been. And even if the administration had decided to punish its wayward allies for not supporting the war, it should never have publicly announced its decision to ban their companies from postwar reconstruction contracts, but merely excluded them without saying a word.

U.S. power is so obvious a fact, particularly to non-Americans, that there is no need to remind anyone of it. If the United States intends to exercise its power effectively, even against the wishes of its allies, it should do so with a bland smile, not boastful words. Weaker states will inevitably view the strongest power as arrogant, inconsiderate, and demanding. There is no need to make it any worse than it must be: Roman discretion offers as important a historical example as Roman assertion.


The military burden of past empires fell not only on the power at the center. The British had their Indian Army, the Romans auxiliaries who proved indispensable to the success of armies built around the legion, itself a masterpiece of ancient military organization. Even the United States has, and will have, far too few soldiers for the tasks at hand. In some ways, Washington has succeeded at handling its own auxiliaries: NATO is, in practical terms, a military alliance that allows the United States to bring forces other than its own to bear on the unstable periphery of Europe. But in other ways, the United States has yet to master the art of developing foreign military institutions, especially when it must do so swiftly. And history suggests that the hope expressed by some U.S. leaders -- of handing off peacekeeping and humanitarian intervention to smaller powers -- is misplaced: the auxiliaries did not fight without the legionaries there to back them up, and the British interlaced the Indian Army with British units and officers.

For Britain, like Rome, imperial governance required proconsuls. The viceroy of India wielded enormous authority, which he often exercised at variance with the views of the government back home. Belief in the superior judgment of "the man on the spot" was the unofficial credo of the British Empire, and although centralizing tendencies existed, they had to yield to the necessities of distance. London had few promising alternatives before the advent of near-instantaneous communication, and travel times in the empire were measured in weeks, not hours. Around the necessity of delegation grew up cultures of initiative, authority, and responsibility, without which empire could not have survived.

The United States does not rule parts of the world in the way the European empires did, but it faces similar challenges. Theater combatant commanders (formerly known as commanders-in-chief, or CINCs) have served as its proconsuls. Their standing in their regions has usually dwarfed that of ambassadors and assistant secretaries of state. They have had the regional outlook, the sophisticated staffs, and the resources to make things happen. It is small wonder that much of U.S. policy abroad has been effectively militarized, at the expense of a State Department whose collective strength has rarely matched the quality of individual diplomats.

As happened in the case of Rome (although to a far lesser degree), these U.S. proconsuls have become politicized. Once out of uniform (and, in some cases, even before) they endorse or denounce politicians; once retired, one recently ran for president, an activity usually reserved for successful commanders in great conflicts. No retired American general, of course, will cross the Rubicon in arms, and their various missteps in recent years will likely cause most of them to return to the dignified silence that characterized many of their predecessors. The phenomenon is revealing, however, because of what it says about the weakness of the civilian side of the U.S. policymaking apparatus -- which has created the vacuum into which generals are drawn.

The United States needs to develop its own versions of viceroys, legates, residents, and procurators. The troubles of Iraq following the overthrow of Saddam Hussein showed that, however skilled its armies, the United States has neither the cadre of administrators nor the organizations necessary to establish order and begin establishing domestic institutions that will prevent a relapse into violence and disorder. Indeed, in this respect especially, the imperial analogy breaks down. In the old days, the great powers -- for reasons of pride, greed, and sheer competitiveness -- desired colonies. In the twenty-first century, in contrast, the projection of power into another country results not from the lure of profit or ambition but from the fear of chaos. Formal colonial rule has lost all legitimacy. And yet, what can substitute for it? International administration of the kind found in Kosovo and Bosnia has a mixed record at best; although the United Nations can usefully provide legitimacy for such rule, and although individuals and organizations have served valiantly and effectively (the name Sergio Vieira de Mello comes to mind), the UN's failures outweigh its successes. And even those successes have required the backing of military powers acting out of traditional self-interest. To legitimize colonial rule by some other name, and to create institutions that can conduct it, has become one of the great challenges of contemporary statecraft -- necessary not only to ease the misery of anarchy, but also to avert the dangers posed by anarchy in the age of weapons of mass destruction and suicide bombers.


History "gives no comfort to the many able, subtle, dedicated minds that crave finality and certitude," Jacques Barzun once noted. But it does offer training for the tough-minded who can tolerate uncertainty and operate within it.

In the end, it makes very little difference whether one thinks of the United States as an empire or as something else -- a hyperpower sui generis, a new order of political entity. Many of the practical problems it faces resemble those faced by past empires, and that alone requires reflection. The results of such reflection, however, are sobering, because soon comes a time when empire no longer looks quite as attractive as it does at the peak of its success and influence. Thucydides captured this by juxtaposing two speeches by the Athenian statesman Pericles. In the great funeral oration delivered over the first casualties of the war with Sparta, he celebrates Athens as "the school of Hellas," "a pattern to others" rather than "imitators ourselves." In words that may remind some of John F. Kennedy at the outset of his presidency, he calls a generation to greatness. Yet after setbacks in war and the ravages of the plague, he warns his countrymen that "to recede is no longer possible, if indeed any of you in the alarm of the moment has become enamored of the honesty of such an unambitious part. For what you hold is, to speak somewhat plainly, a tyranny; to take it perhaps was wrong, to let go is unsafe."

Herein lies one of the curses of empire: to let go never looks safe, and indeed rarely is. The United Kingdom withdrew from its leading role in world affairs without too much damage to itself (although at the price of massive bloodshed in places such as India and Yemen), but that had much to do with the readiness of the United States to take its place -- to fill the vacuum left by British power and take up the British role in many parts of the world. Nor did the British have much choice in their withdrawal from empire, other than by, as Machiavelli put it, "anticipating necessity," pulling back just before forces too strong for them to master would have compelled them.

The United States today also has less choice about its role in world affairs than its worried leaders and their critics, or its anxious friends and numerous enemies, think. The logic of empire is a logic of extension, and the strategic conundrum of empire is that of overcommitment and overstretch. Despite the wishes of French and Chinese politicians, no countervailing state or federation will restore a balance-of-power system akin to that of Europe in the eighteenth and nineteenth centuries, at least not in the near future. Despite the wishes of idealists, no international institution has proven capable of effective action in the absence of the power generated and exercised by states. And a third possibility -- anarchy unleashed after a disgusted United States recalls its legions in a spurt of democratic disgust at and indifference to the rest of the planet -- is too horrifying to contemplate. The real alternatives, then, are U.S. hegemony exercised prudently or foolishly, consistently or fecklessly, safely or dangerously -- and for this, U.S. leaders must look back to school themselves in the wisdom that will make such statesmanship possible.

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  • Eliot A. Cohen is Robert E. Osgood Professor and Director of the Philip Merrill Center for Strategic Studies at Johns Hopkins University's School of Advanced International Studies and the author of Supreme Command: Soldiers, Statesmen, and Leadership in Wartime.
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