THE URGE to apply era-defining labels to global affairs is strong and enduring. A label and a few easy-to-understand attributes associated with it can impart a reassuring simplicity to what is actually a complex and often-intractable reality. While the disadvantages of era labeling, including oversimplification, are probably as great as the advantages, the practice is here to stay.

Indeed, American analysts and commentators have struggled with this era-defining business ever since the collapse of the Soviet Union and of Communism in Eastern Europe. The Cold War between the United States and the USSR was such a dominant backdrop for U.S. foreign policy for so long that it overshadowed every attempt to characterize international affairs in any other terms during those years. The strength of the Cold War paradigm was demonstrated during the first decade after the Cold War, when the defining term most often heard was “the post–Cold War era.” That inherently unsatisfying nomenclature described what the era wasn’t but not what it was. Some attempted to encapsulate the times some other way, usually with an emphasis on economically oriented nonstate actors, but no one formula seemed to catch on.

Then, with the terrorist attacks of September 2001, after which the administration of George W. Bush declared a global “war on terror,” many thought we finally had a new defining theme. Some saw in this struggle nothing less than a looming “World War IV,” to be waged against radical Islam (with the Cold War viewed as the third world war after the two hot global conflicts of the twentieth century). This notion persists in many minds, but neither terrorism nor radical Islam provides a valid basis for understanding and characterizing current international affairs as a whole. Terrorism is only a tactic, and one that has been around for millennia. Radical Islamists are a fringe of a larger phenomenon in world politics, hardly of sufficient worldwide weight to reshape global affairs. Hence, much of this reasoning represents in large part an overreaction to a single terrorist incident.

And therein lies a problem with the era-defining enterprise. Most such efforts use too short a time frame and attempt to extract too broad a theme from single episodes, such as the breakup of the Soviet Union or Al Qaeda’s 9/11 attacks on American soil. But an understanding of the present requires that we look much further into the past, not to stretch the time frame of various eras but rather to get a sufficient sweep of political, social and technological developments to truly understand how the present has flowed from what came before.

By looking far back into history, we can see in the past two decades the long-in-coming consequences of that phenomenon known as nationalism but now in full and unfettered form. It took three and a half centuries for the basic components—the sovereign state, popular attachment to the state and worldwide spread of this popular attachment—to emerge in full force. It took two centuries to shake off the occluding and delaying effects of empire and of Left-Right competition that culminated in the dominating East-West conflict known as the Cold War. The ingredients of nationalism may be centuries old, but the combined result, viewed globally, is new. We are living today in the nationalist era.

THIS REALITY of our time has been obscured in recent years by the intellectual struggles of the early post–Cold War period to define the era and then by the impact of the 9/11 attacks on the American consciousness. In some instances, the two together have generated an added layer of muddle. Some of the ideas about World War IV, for example, reflect the concept of clashing civilizations developed by the late Samuel P. Huntington, who argued that among the many dimensions of civilizations, as he defined them, the most important is religion. Huntington was on to something, as demonstrated by the role of religion in many armed conflicts, large and small, in recent times. Yet there is plenty of evidence to support the chief legitimate criticism of Huntington’s concept, which is that there is at least as much conflict within civilizations as between them. We are seeing that in spades today with conflicts within Islam, one of Huntington’s civilizations.

More generally, ask any group of reasonably well-informed observers to name the principal characteristics of the current global system, and you are likely to get agreement on a few essentials. The United States is still the preeminent military power. China is the most conspicuous and important rising power, with its strength manifesting itself so far more on the economic than the military front. Demographic trends underlie decline in Russia and Japan. And so forth. All true, but the essentials do not add up to a single, clear, era-defining concept.

The polarity of the international system—the number of major powers or blocs of powers that have disproportionate weight in world affairs—is a favorite basis for trying to distinguish one era from another. A generation of students of international relations has been taught that the world of the Cold War was bipolar and the world since the Cold War is something else. Exactly what that something else is, however, has been a matter of disagreement.

Some say we live in a unipolar world, with the United States being the single pole. What commentator Charles Krauthammer termed the “unipolar moment” in 1990 continues in some eyes as much more than a moment. This view is held not only by those who share Krauthammer’s neoconservative objectives but also by analysts who look at how far the United States is still ahead of all other countries, based on several measures of strength. An alternative concept is multipolarity, with different possible formulations of who exactly, besides the United States, qualifies as a pole. China surely is one, and another is the European Union—which contains most of what were once the great powers in an earlier period of multipolarity and whose economy today, considered as a unit, is the world’s largest.

Some focus on a duopoly of China and the United States, with talk of a G-2 as being more important than the G-8 or G-20. Even with this focus, how should one characterize the relationship of the Big Two, which cannot simply be equated with the U.S.-Soviet relationship during the Cold War? Harvard Law School’s Noah Feldman suggests the term “Cool War” to capture both a traditional struggle for power and deep economic interdependence. Clever, though probably not catchy enough to come into general use. In any event, this and other possible descriptions of the U.S.-Chinese relationship—which does not have the kind of globally preoccupying impact, including proxy wars in far-flung places, that the Cold War did—do little to characterize contemporary world affairs as a whole.

Richard Haass, president of the Council on Foreign Relations, advances another option by saying that we live in a time of “nonpolarity,” in which power is diffused among many different state and nonstate actors. This idea, along with ongoing disagreements among others about how many poles the current international system has, suggests that the whole concept of polarity doesn’t really help define the current era of global affairs. One problem is the multiplicity of dimensions by which to measure national power and thus to assess who qualifies as a major power. Another is that a large portion of what matters, and what is troubling or challenging, in world affairs today does not have much to do with the number, relative strength or relationships of major powers, important as they are. Haass’s idea of nonpolarity reflects this reality, but like “the post–Cold War era,” it says more about what today’s world isn’t than about what it is.

ALL THIS debate over how best to define our time brings us back to the nation-state. Over the entire history of human organization, from bands of hunter-gatherers to the international institutions of today, its emergence is one of the most important developments of humankind. Those international-relations courses that drill into students the concept of Cold War bipolarity also teach them that the modern nation-state was born in the mid-seventeenth century. The birth certificate was the Peace of Westphalia of 1648, which marked the end of the religion-driven Thirty Years’ War and codified the concept of state sovereignty. What is sometimes called the Westphalian system is reflected in the clean lines drawn between states on today’s world map.

During the first century and a half of that system in Europe, it provided the board on which monarchs and their ministers competed in a multiplayer chess game. This was classical European balance-of-power politics, history’s most pristine example of multipolarity in action, in which the number and relative strength of major powers mattered much more than ideologies or internal politics. Rulers formed alliances, occasionally fought restrained wars with small armies, and otherwise maneuvered to try to add more land and people to their realms. The masses were not players in this game other than as part of the booty that occasionally was won by one ruler and lost by another.

This elegant game was upset by the French Revolution, in which the masses first made themselves heard in a big way. They did so not only in internal affairs but also in conflicts between France and the other European powers, with the levy en masse becoming for the first time a major part of international wars and the increasingly large armies that would fight them. Large citizen armies, even if formally an output of conscription, were made politically possible by a strong sense of loyalty and attachment of the general population to its nation-state—a sense that had been missing during the earlier monarchical chess game. The combination of the Westphalian state and popular, emotional identification with it produced true nationalism, in which both statehood (actual or aspirational) and mass sentiment based on the nation are the key ingredients.

The full impact of nationalism on world affairs and even European affairs would be delayed, however, by other developments. One was the force of empire. Napoleon Bonaparte’s attempt at empire was short lived, but Russian, Prussian and Austrian power expanded to subsume much of Europe, while the Ottomans clung to earlier conquests in the southeastern part of the Continent. State sovereignty was divorced from many nationalities other than the few that were at the top of an imperial heap. Many others were repressed or divided, such as the Poles, or co-opted, such as the Magyars in what became the dual monarchy of Austria-Hungary.

Although this remained the political structure of Europe into the twentieth century, other processes were percolating that would add to the strength of future nationalism. The historian E. H. Carr, in a short book entitled Nationalism and After, describes some of these, which he calls the “socialization of the nation.” Relevant trends during the last third of the nineteenth century, seen especially in Germany, included extension of the franchise and an increased economic role of the state. Together, these factors further increased the sense among ordinary citizens not only that their primary loyalty belonged to their own nation-state but also that their own fortunes were wrapped up with the nation-state’s fortunes. These trends continued into the great nationalism-fueled European bloodletting known as World War I.

That war did not reverse the increase in nationalism, and not only because revanchism left from the war was at least as strong as revulsion over the bloodshed. Carr points to a couple of other reasons: autarkic policies that further identified citizens’ economic prospects with those of only their own state and not others; and the large increase in the number of European nation-states as empires were broken up. There was plenty of nationalist sentiment left to fuel a second round of carnage two decades later.

Carr wrote during the closing days of that World War II bloodletting. Showing tinges of the Marxism that would characterize some of his later work, he believed that after this war nationalism would finally subside—hence the “and after” part of his title. Some of his predictions turned out to be rather good. He expected that advances in military technology, especially air power, would render national frontiers strategically less significant than before. He anticipated the establishment of multiple regional organizations and what would become United Nations peacekeeping forces. He foresaw that Great Britain would have to establish closer ties with Western Europe. He advocated humanitarian exceptions to state sovereignty—a posture that today is called the “responsibility to protect” doctrine. And he foreshadowed Huntington in talking about civilizations as “great multinational units in which power will be concentrated.”

On his basic prognosis for nationalism, however, Carr was badly mistaken. Given his firm conviction that the end of World War II would mark the end “of the old fissiparous nationalism, of the ideology of the small nation as the ultimate political and economic unit,” it seems reasonable to suspect he would be taken aback in our time to see nations as small as Kosovo gaining independence. And he would be chagrined to find that in his native Britain, even though it did get closer to the Continent in the postwar years, there is more talk today about getting out of Europe than about getting more deeply in.

THE FULL extent to which strong and inexorable nationalism would prove Carr wrong would not become visible until after a couple of other developments. One was decolonization in the less developed world, which peaked around 1960 but continued well after that. This process has added new nation-states whose numbers dwarf the new European states that were created after World War I and that Carr identified as part of what propelled nationalism in the interwar years. The Westphalian state has been sold successfully worldwide, despite its made-in-Europe label.

The other development harks back again to the French Revolution, which began two centuries in which competition between ideologies of the Left and the Right was a dominant theme of global politics and conflict. Between the fall of the Bastille in 1789 and the fall of the Berlin Wall in 1989, Left-Right conflict had many manifestations, from the Holy Alliance and Three Emperors’ League on the right to the Comintern and Socialist International on the left. Whatever the exact form it took, the Left-Right dimension was so dominant for so long—more than half the lifetime of the modern nation-state—that it preempted, disguised or diverted much of what would have been consequences of the growth of nation-states and popular attachment to them. Left-Right conflict intruded in significant ways even in the nationalism-fueled conflict of the first part of the twentieth century, exemplified by the Bolsheviks’ quick relinquishment at Brest-Litovsk of large amounts of the Russian empire to get out of World War I and by the role that fear of Communism played in the rise of European fascism.

The final phase of these two centuries was the Cold War, in which competition between the Left and the Right became competition between East and West. This phase, too, delayed or disguised many of the consequences of nationalism, subordinating them to the East-West conflict. Suppression of German nationalism, for example, was inextricably linked to the West’s confrontation with the East, as rearmament of West Germany was permitted only within the context of the Western alliance’s integrated military command. Britain’s willingness to tiptoe into European integration, as a founding member of the Western Union Defence Organization in 1948, was all about the need for cohesion in the West to stand up to a new Soviet threat. Soviet domination of Eastern Europe also delayed completion of the process, begun at Versailles after World War I, of giving postimperial European nationalities their own states. It was only after that domination ended that Germany was made whole and the southern Slavs of Yugoslavia and northern Slavs of Czechoslovakia got their own states. As did, of course, the national republics of the Soviet Union, which became the biggest recent class of entrants into the Westphalian club.

And so we see the emergence of the nation-state as the defining reality of our time, surpassing in significance all the recent preoccupations over civilizational clash, globalization, history’s end and great-power polarity. Indeed, it could be argued that the age of nationalism actually is a product of the human condition.

That the nation-state should be the primary focus of loyalties and conflicts flows directly from human nature and how it evolved. Possession (or hoped-for possession) of a well-defined patch of the earth’s surface is a manifestation of the “territorial imperative” that author and screenwriter Robert Ardrey popularized in a book of that name almost fifty years ago and that is a dominant trait of many species most closely related to humans. Attachment to a nationality whose home is more or less coterminous with that patch is also a deeply rooted, birds-of-a-feather trait. Once established, a nation-state adds institutional imperatives to the biological and evolutionary ones to make it even more the focus of attention. The state becomes the source of both obligations and, as Carr notes of the late nineteenth century, benefits. National myths, which help to achieve cohesion and cement loyalty within nationalities, often exacerbate suspicions and resentment between nationalities; think, for example, of how some Serbian national mythology centers on memories of a military defeat by the Turks more than seven centuries ago. Perhaps nation-states, including small ones, are not, as Carr puts it, the “ultimate” type of economic and political unit, but it should not be surprising that the intense attachments to them that constitute nationalism underlie a large proportion of the policies, conflicts and problems prevalent in today’s world.

NATIONALISM INFUSES and drives many of the most salient and active confrontations around the globe. The object of the Obama administration’s foreign-policy pivot—East Asia and the western Pacific—is a prime example. The most visible conflicts there largely take the classic nationalist form of territorial disputes. This is chiefly true of unresolved differences between China and its neighbors over islands in the East and South China Seas and over the land border in the Himalayas with India. Some of the disputes involve economic interests such as hoped-for undersea hydrocarbons, but all of them involve more visceral sentiments of competing nationalities, exhibiting their individual territorial imperatives, that a given piece of real estate is historically and rightfully theirs.

Nationalism in China, as in most other nations, is a combination of natural sentiment bubbling up from below and exploitation of that sentiment from above. President Xi Jinping voices nationalist themes, and needs to voice them, not only to preserve national unity but also to sustain political support for necessary reforms and to claim legitimacy for the regime now that Communist ideology no longer does the trick. China, which owes its growth and prosperity to its three-decade capitalist trek, epitomizes how the receding of the great Left-Right struggle of the past has opened the way to more unreserved expressions of nationalism.

China also illustrates how some of the globalizing forces such as border-hopping information technology, which often have been seen as eroding the role of the nation-state, can actually enhance that role and increase popular identification with the nation. In a country as large and previously undeveloped as China, modern mass communications have expanded the exposure and perspective of millions from village or district to the nation as a whole. In general, modern electronic communications enhance the symbols and affinities of a nation (as well as the powers of a national government) more than they do those of a tribe or subnational region.

The role of nationalism is just as apparent on the non-Chinese side of those East Asian territorial disputes. In Japan, the resurgent nationalism that is identified most often with Prime Minister Shinzo Abe reflects the broader yearning of an exceptionally homogeneous population that has taken decades to find a capacity for the kind of assertiveness that was crushed by the disaster of World War II. In Vietnam, the nationalism that the United States failed to recognize as its actual adversary during the Vietnam War, when it was obsessed with Communist ideology, is now expressed so clearly and strongly that even the most obtuse could not miss it. Amid the disputes over islands in the South China Sea, demonstrators in the streets of Hanoi shout, “Down with the henchmen of China.” The Vietnamese regime knows that suppressing rather than identifying with such feelings toward China would risk turning the demonstrations squarely against the government.

The magnificent supranational experiment in Europe is an obvious challenge to the proposition that identification with the nation-state is the dominant pattern in world politics today. That experiment has indeed solidified an apparently irreversible shift in which war is now unthinkable between some states that have warred often in the past. But a reassertion of nationalism is a major part of the European Union’s current troubles, in ways that go beyond the economic issues conventionally viewed as the main problems. Efforts to deal with debt problems in the euro zone have been plagued as much by national stereotypes, in which northern Europeans see southerners as lazy and southerners see the northerners as arrogant, as they have by the technical problems of having a common monetary policy without a common fiscal policy. The growing strength of nation-based sentiment in Europe shows up in many endeavors that are still organized along national lines, from soccer tournaments to the Eurovision Song Contest.

Britain’s shaky involvement with European integration illustrates some of the larger trends involved. When Britain was first negotiating for entry into what was then the European Economic Community, most of the issues were narrowly defined economic ones, such as what would happen to imports of butter from New Zealand. Today the issue of Britain’s relationship with the Continent is addressed in broader terms centered on the meaning and importance of British nationality. This trend coincides with the rise of the United Kingdom Independence Party (UKIP), which calls for British withdrawal from the European Union. Prime Minister David Cameron once dismissed the party as “a bunch of fruitcakes, loonies and closet racists,” but the UKIP’s electoral success—it garnered a quarter of the vote in local council elections this May—has forced opponents to take it seriously. The Cameron government’s toughened stance on immigration and commitment to hold a referendum on British membership in the EU are some of the results.

Cameron also has agreed with Scottish nationalists to hold a referendum on independence. This is an example of how the transfer of some powers from national capitals to Brussels, far from diminishing nationalist sentiment, has provided a supranational umbrella under which some nationalities, especially ones unhappy with the arrangements within their current states, have become more assertive. These include Flemings and Catalonians as well as Scots.

However successful the European experiment will ultimately be economically and in forever banishing intra-European war, it has far to go in establishing a sense of continent-wide identity that can displace national identities grounded in language and culture. Even greater cultural and linguistic commonality may, as the example of Latin America suggests, be insufficient to overshadow the histories and identities of nation-states. The Liberator, Simón Bolívar, thought a shared Hispanic culture could be the basis for a region-wide federation, but it was not to be. Today the Andean country named after Bolívar does not even have full diplomatic relations with its neighbor Chile, due to a territorial dispute left over from a nineteenth-century war.

Africa continues to be a monument to the strength of the nation-state as a point of reference and object of competition, no matter how arbitrarily drawn its boundaries or deficient its central governments’ control over their territories. The secession of South Sudan was a rare exception to a continent-wide resistance to tampering with the colonial boundaries left by European powers. A similar pattern has prevailed since the breakup of the Soviet Union in Central Asia, where arbitrary boundaries are the product of Stalin’s divide-and-rule line drawing. The arbitrariness underlies some intrastate ethnic tensions such as those between Uzbeks and Kyrgyz, but nationalist themes also have helped such figures as Nursultan Nazarbayev of Kazakhstan to transition successfully from a provincial Communist Party boss to a national leader with a secure hold on power.

The USSR’s principal successor state, Russia, has exhibited a surge of nationalism since the Communist regime’s dissolution. The process partly parallels the one in China, in which the old Communist ideology could no longer serve as a unifier and legitimizer. But in Russia there is also popular anger over economic dislocation and the lack of growth, as well as perceived threats to ethnic Russians from minorities that are still part of the Russian Federation. The term “Russian nationalist” is thus most closely associated with a xenophobic and extreme-right sensibility, although the nationalist resurgence in Russia extends far beyond that.

Some of the intensified Russian nationalism has in effect been exported in the form of migrants to Israel. The migrants shared with all Soviet citizens the illiberal and undemocratic political culture of the Communist era, along with racially tinged attitudes toward nationalities of the Caucasus. But Russian Jews did not have their own national republic to cling to when the union broke up. Today, immigrants from Russia constitute one of the most fervidly nationalist segments of Israel’s population.

The region surrounding Israel would appear to constitute another challenge to the idea of the dominance of nationalism, given the conspicuous attention to religion rather than nationality and especially to what is commonly perceived as a region-wide conflict between Sunni and Shia. That attention is a reminder that no one way of labeling the world explains everything, and religious conflict certainly explains a lot in the Middle East. Many of the recent and ongoing conflicts in that region, however, can properly be characterized, at least in part, as struggles to liberate nation-states from the yoke of particular clans, ruling families or religious sects, or from the influence of foreign powers. That certainly is true, for example, of the wars in Iraq and Syria. Nationality has trumped religion when the two have directly conflicted, as when Iraqi Shia fought for Sunni-controlled Iraq during the eight-year war against Shia Iran. Identification with individual nation-states has been more durable even than region-wide “Arab nationalism,” including the Arab nationalism of Pan-Arabism’s leading champion, Gamal Abdel Nasser, whose political union between Egypt and Syria was short lived. The boundary lines drawn during World War I by Mark Sykes and Francois Georges-Picot have lasted, just like the colonial boundaries in Africa. The leading challenge to those lines, in northern Iraq, has come from the biggest unrealized nationalist aspiration left over from the post–World War I treaties: that of the Kurds. Likewise, the most salient long-running conflict with the broadest repercussions in the Middle East is a clash between two nationalist ambitions: those of Israeli Jews and Palestinian Arabs.

THE FACT that nationalism in the Middle East has not yet gotten completely out from the shadow of religious conflict, as nation-states in Europe did in the seventeenth century, is part of a larger regional historical lag in which the Middle East also has been slower to get out from the shadow of empire. Historian Niall Ferguson, explaining why the twenty-first century is likely to be less bloody in most of the world than the twentieth, cites as one reason the fact that the messy dissolution of empires is now mostly behind us. But he names one major, conflict-ridden regional exception—the Middle East—where an empire is troubled but not yet dissolved, by which he means the American empire.

Troubled empire or not, the United States exhibits as much nationalism as anyone else—even though Americans do not call it nationalism. More often it is termed “American exceptionalism,” which carries the connotation not just of assertion of national identity and values but also of being something bigger and better than anyone else’s nationalism. Exceptionalism is what the citizens of a superpower get to call their own nationalism.

The United States also is part of the worldwide trend of increased and intensified nationalism during the past quarter century. Politically, this has partly taken the form of one of the two major U.S. parties moving away from the internationalism and realism of Eisenhower and Nixon in favor of a foreign policy of neoconservatism, the most muscular expression of American exceptionalism. A perceptive analyst of American nationalism, Anatol Lieven, suggests that this party can now most appropriately be called the American Nationalist Party. The trends involved are not limited to one side of the political spectrum, however; they are reflected in prevailing American habits and attitudes ranging from the wearing of flag pins on lapels to unquestioningly imputing goodness to a wide range of U.S. actions overseas simply because it is the United States that is doing them.

The intensity of American nationalism points to the chief prescriptive implications of living in the nationalist era, which come under the heading of knowing oneself. Americans should understand how much their own first inclinations for interacting with the rest of the world stem from the same kind of nationalist urges that underlie inclinations in other countries, however much the American version is portrayed differently by affixing the label of exceptionalism. They should bear in mind that first inclinations and urges are not always in the best interest of the nation that is the object of their affection and attachment. U.S. policy makers should be continually conscious of how U.S. actions may step on someone else’s nationalist sentiments, eliciting the sort of counteractions that almost always are elicited when competing nationalist perspectives confront each other.

In assessing sundry problems overseas and how to deal with them, one of the first questions that should be asked is how a problem reflects nationalist sensibilities and ambitions, of masses as well as elites, in other countries. The resulting perspective is more apt to yield sound, policy-relevant insights than is a vision of transnational contests between good and evil, between moderates and extremists, or between democrats and autocrats. Sometimes the policy implication may be for the United States to do less; other times it may be to do more—as perhaps, for example, with the Israeli-Palestinian conflict, where a two-state solution appears increasingly out of reach but where a one-state formula seems inconsistent with the strong nationalist aspirations of both sides.

No single model of the world can generate an all-purpose grand strategy. But the best fit for the nationalist era is a pragmatic realism that takes as the basic ingredient of global affairs the sometimes conflicting and sometimes parallel interests of individual nation-states—while recognizing the power that can be generated by nationalist sentiments within nation-states.

Paul R. Pillar is a contributing editor at The National Interest. He is also a nonresident senior fellow at the Brookings Institution and a nonresident senior fellow at Georgetown University’s Center for Security Studies.

Image: Pullquote: Exceptionalism is what the citizens of a superpower get to call their own nationalism.Essay Types: Essay