Myth of multipolarity - American power staying power Analysis by Foreign Affairs

The Foreign Affairs magazine has published an article arguing that the United States still possesses vast economic leverage, but it has a greater need to act in concert with its allies to make sanctions effective. Caliber.Az reprints the article.

In the 1990s and the early years of this century, the United States’ global dominance could scarcely be questioned. No matter which metric of power one looked at, it showed a dramatic American lead. Never since the birth of the modern state system in the mid-seventeenth century had any country been so far ahead in the military, economic, and technological realms simultaneously. Allied with the United States, meanwhile, were the vast majority of the world’s richest countries, and they were tied together by a set of international institutions that Washington had played the lead role in constructing. The United States could conduct its foreign policy under fewer external constraints than any leading state in modern history. And as dissatisfied as China, Russia, and other aspiring powers were with their status in the system, they realized they could do nothing to overturn it.

That was then. Now, American power seems much diminished. In the intervening two decades, the United States has suffered costly, failed interventions in Afghanistan and Iraq, a devastating financial crisis, deepening political polarization, and, in Donald Trump, four years of a president with isolationist impulses. All the while, China continued its remarkable economic ascent and grew more assertive than ever. To many, Russia’s 2022 invasion of Ukraine sounded the death knell for US primacy, a sign that the United States could no longer hold back the forces of revisionism and enforce the international order it had built.

According to most observers, the unipolar moment has come to a definitive end. Pointing to the size of China’s economy, many analysts have declared the world bipolar. But most go even further, arguing that the world is on the verge of transitioning to multipolarity or has already done so. China, Iran, and Russia all endorse this view, one in which they, the leading anti-American revisionists, finally have the power to shape the system to their liking. India and many other countries in the global South have reached the same conclusion, contending that after decades of superpower dominance, they are at last free to chart their own course. Even many Americans take it for granted that the world is now multipolar. Successive reports from the US National Intelligence Council have proclaimed as much, as have figures on the left and right who favor a more modest US foreign policy. There is perhaps no more widely accepted truth about the world today than the idea that it is no longer unipolar.

But this view is wrong. The world is neither bipolar nor multipolar, and it is not about to become either. Yes, the United States has become less dominant over the past 20 years, but it remains at the top of the global power hierarchy—safely above China and far, far above every other country. No longer can one pick any metric to see this reality, but it becomes clear when the right ones are used. And the persistence of unipolarity becomes even more evident when one considers that the world is still largely devoid of a force that shaped great-power politics in times of multipolarity and bipolarity, from the beginning of the modern state system through the Cold War: balancing. Other countries simply cannot match the power of the United States by joining alliances or building up their militaries.

American power still casts a large shadow across the globe, but it is admittedly smaller than before. Yet this development should be put in perspective. What is at issue is only the nature of unipolarity—not its existence.

Minor third

During the Cold War, the world was undeniably bipolar, defined above all by the competition between the United States and the Soviet Union. After the collapse of the Soviet Union, the world turned unipolar, with the United States clearly standing alone at the top. Many who proclaim multipolarity seem to think of power as influence—that is, the ability to get others to do what you want. Since the United States could not pacify Afghanistan or Iraq and cannot solve many other global problems, the argument runs, the world must be multipolar. But polarity centers on a different meaning of power, one that is measurable: power as resources, especially military might and economic heft. And indeed, at the root of most multipolarity talk these days is the idea that scholarly pioneers of the concept had in mind: that international politics works differently depending on how resources are distributed among the biggest states.

For the system to be multipolar, however, its workings must be shaped largely by the three or more roughly matched states at the top. The United States and China are undoubtedly the two most powerful countries, but at least one more country must be roughly in their league for multipolarity to exist. This is where claims of multipolarity fall apart. Every country that could plausibly rank third—France, Germany, India, Japan, Russia, the United Kingdom—is in no way a rough peer of the United States or China.

That is true no matter which metric one uses. Polarity is often still measured using the indicators fashionable in the mid-twentieth century, chiefly military outlays and economic output. Even by those crude measures, however, the system is not multipolar, and it is a sure bet that it won’t be for many decades. A simple tabulation makes this clear: barring an outright collapse of either the United States or China, the gap between those countries and any of the also-rans will not close anytime soon. All but India are too small in population to ever be in the same league, while India is too poor; it cannot possibly attain this status until much later in this century.

These stark differences between today’s material realities and a reasonable understanding of multipolarity point to another problem with any talk of its return: the equally stark contrast between today’s international politics and the workings of the multipolar systems in centuries past. Before 1945, multipolarity was the norm. International politics featured constantly shifting alliances among roughly matched great powers. The alliance game was played mainly among the great powers, not between them and lesser states. Coalition arithmetic was the lodestar of statecraft: shifts in alliances could upset the balance of power overnight, as the gain or loss of a great power in an alliance dwarfed what any one state could do internally to augment its own power in the short run. In 1801, for example, the Russian emperor Paul I seriously contemplated allying with rather than against Napoleon, heightening fears in the United Kingdom about the prospect of French hegemony in Europe—worries that may have, according to some historians, led the British to play a role in Paul’s assassination that same year.

Today, almost all the world’s real alliances (the ones that entail security guarantees) bind smaller states to Washington, and the main dynamic is the expansion of that alliance system. Because the United States still has the most material power and so many allies, unless it abrogates its own alliances wholesale, the fate of great-power politics does not hinge on any country’s choice of partners.

In multipolar eras, the relatively equal distribution of capabilities meant that states were often surpassing one another in power, leading to long periods of transition in which many powers claimed to be number one, and it wasn’t clear which deserved the title. Immediately before World War I, for example, the United Kingdom could claim to be number one on the basis of its global navy and massive colonial holdings, yet its economy and army were smaller than those of Germany, which itself had a smaller army than Russia—and all three countries’ economies were dwarfed by that of the United States. The easily replicable nature of technology, meanwhile, made it possible for one great power to quickly close the gap with a superior rival by imitating its advantages. Thus, in the early twentieth century, when Germany’s leaders sought to take the United Kingdom down a peg, they had little trouble rapidly building a fleet that was technologically competitive with the Royal Navy. The situation today is very different. For one thing, there is one clear leader and one clear aspirant. For another, the nature of military technology and the structure of the global economy slow the process of the aspirant overtaking the leader. The most powerful weapons today are formidably complex, and the United States and its allies control many of the technologies needed to produce them.

The multipolar world was an ugly world. Great-power wars broke out constantly—more than once a decade from 1500 to 1945. With frightening regularity, all or most of the strongest states would fight one another in horrific, all-consuming conflicts: the Thirty Years’ War, the Wars of Louis XIV, the Seven Years’ War, the Napoleonic Wars, World War I, and World War II. The shifting, hugely consequential, and decidedly uncertain alliance politics of multipolarity contributed to these conflicts. So did the system’s frequent power transitions and the fleeting nature of leading states’ grasp on their status. Fraught though the current international environment may be compared with the halcyon days of the 1990s, it lacks these inducements to conflict and so bears no meaningful resemblance to the age of multipolarity.

Don't bet on bipolarity

Using GDP and military spending, some analysts might make a plausible case for an emergent bipolarity. But that argument dissolves when one uses metrics that properly account for the profound changes in the sources of state power wrought by multiple technological revolutions. More accurate measures suggest that the United States and China remain in fundamentally different categories and will stay there for a long time, especially in the military and technological realms.

No metric is invoked more frequently by the heralds of a polarity shift than GDP, but analysts in and outside China have long questioned the country’s official economic data. Using satellite-collected data about the intensity of lights at night—electricity use correlates with economic activity—the economist Luis Martinez has estimated that Chinese GDP growth in recent decades has been about one-third lower than the officially reported statistics. According to leaked US diplomatic cables, in 2007, Li Keqiang, a provincial official who would go on to become China’s premier, told the US ambassador to China that he himself did not trust his country’s “man-made” GDP figures. Instead, he relied on proxies, such as electricity use. Since Xi took power, reliable data on the Chinese economy has gotten even harder to come by because the Chinese government has ceased publishing tens of thousands of economic statistics that were once used to estimate China’s true GDP.

But some indicators cannot be faked. To evaluate China’s economic capacity, for example, consider the proportion of worldwide profits in a given industry that one country’s firms account for. Building on the work of the political economist Sean Starrs, research by one of us (Brooks) has found that of the top 2,000 corporations in the world, US firms are ranked first in global profit shares in 74 percent of sectors, whereas Chinese firms are ranked first in just 11 percent of sectors. The data on high-tech sectors is even more telling: US firms now have a 53 percent profit share in these crucial industries, and every other country with a significant high-tech sector has a profit share in the single digits. (Japan comes in second at seven percent, China comes in third at six percent, and Taiwan comes in fourth at five percent.)

The best way to measure technological capacity is to look at payments for the use of intellectual property—technology so valuable that others are willing to spend money on it. This data shows that China’s extensive R & D investments over the past decade are bearing fruit, with Chinese patent royalties having grown from less than $1 billion in 2014 to almost $12 billion in 2021. But even now, China still receives less than a tenth of what the United States does each year ($125 billion), and it even lags far behind Germany ($59 billion) and Japan ($47 billion).

Militarily, meanwhile, most analysts still see China as far from being a global peer of the United States, despite the rapid modernization of Chinese forces. How significant and lasting is the US advantage? Consider the capabilities that give the United States what the political scientist Barry Posen has called “command of the commons”—that is, control over the air, the open sea, and space. Command of the commons is what makes the United States a true global military power. Until China can contest the United States’ dominance in this domain, it will remain merely a regional military power. We have counted 13 categories of systems as underlying this ability—everything from nuclear submarines to satellites to aircraft carriers to heavy transport planes—and China is below 20 percent of the US level in all but five of these capabilities, and in only two areas (cruisers and destroyers; military satellites) does China have more than a third of the US capability. The United States remains so far ahead because it has devoted immense resources to developing these systems over many decades; closing these gaps would also require decades of effort. The disparity becomes even greater when one moves beyond a raw count and factors in quality. The United States’ 68 nuclear submarines, for example, are too quiet for China to track, whereas China’s 12 nuclear submarines remain noisy enough for the US Navy’s advanced antisubmarine warfare sensors to track them in deep water.

A comparison with the Soviet Union is instructive. The Red Army was a real peer of the US military during the Cold War in a way that the Chinese military is not. The Soviets enjoyed three advantages that China lacks. First was favorable geography: with the conquest of Eastern Europe in World War II, the Soviets could base massive military force in the heart of Europe, a region that comprised a huge chunk of the world’s economic output. Second was a large commitment to guns over butter in a command economy geared toward the production of military power: the percentage of GDP that Moscow devoted to defense remained in the double digits throughout the Cold War, an unprecedented share for a modern great power in peacetime. Third was the relatively uncomplicated nature of military technology: for most of the Cold War, the Soviets could command their comparatively weak economy to swiftly match the United States’ nuclear and missile capability and arguably outmatch its conventional forces. Only in the last decade of the Cold War did the Soviets run into the same problem that China faces today: how to produce complex weapons that are competitive with those emerging from a technologically dynamic America with a huge military R & D budget (now $140 billion a year).

Bipolarity arose from unusual circumstances. World War II left the Soviet Union in a position to dominate Eurasia, and with all the other major powers save the United States battered from World War II, only Washington had the wherewithal to assemble a balancing coalition to contain Moscow. Hence the intense rivalry of the Cold War: the arms race, the ceaseless competition in the Third World, the periodic superpower crises around the globe from Berlin to Cuba. Compared with multipolarity, it was a simpler system, with only one pair of states at the top and so only one potential power transition worth worrying about.

With the demise of the Soviet Union and the shift from bipolarity to unipolarity, the system transformed from one historically unprecedented situation to another. Now, there is one dominant power and one dominant alliance system, not two. Unlike the Soviet Union, China has not already conquered key territory crucial to the global balance. Nor has Xi shown the same willingness as Soviet leaders to trade butter for guns (with China long devoting a steady two percent of GDP to military spending). Nor can he command his economy to match US military power in a matter of years, given the complexity of modern weaponry.

Partially unipolar

To argue that today’s system is not multipolar or bipolar is not to deny that power relations have changed. China has risen, especially in the economic realm, and great-power competition has returned after a post–Cold War lull. Gone are the days when the United States’ across-the-board primacy was unambiguous. But the world’s largest-ever power gap will take a long time to close, and not all elements of this gap will narrow at the same rate. China has indeed done a lot to shrink the gap in the economic realm, but it has done far less when it comes to military capacity and especially technology.

As a result, the distribution of power today remains closer to unipolarity than to either bipolarity or multipolarity. Because the world has never experienced unipolarity before the current spell, no terminology exists to describe changes to such a world, which is perhaps why many have inappropriately latched on to the concept of multipolarity to convey their sense of a smaller American lead. Narrowed though it is, that lead is still substantial, which is why the distribution of power today is best described as “partial unipolarity,” as compared with the “total unipolarity” that existed after the Cold War.

The end of total unipolarity explains why Beijing, Moscow, and other dissatisfied powers are now more willing to act on their dissatisfaction, accepting some risk of attracting the focused enmity of the United States. But their efforts show that the world remains sufficiently unipolar that the prospect of being balanced against is a far stiffer constraint on the United States’ rivals than it is on the United States itself.

Ukraine is a case in point. In going to war, Russia showed a willingness to test its revisionist potential. But the very fact that Russian President Vladimir Putin felt the need to invade is itself a sign of weakness. In the 1990s, if you had told his predecessor, Boris Yeltsin, that in 2023, Russia would be fighting a war to sustain its sphere of influence over Ukraine, which Russian officials back then assumed would end up as a reliable ally, he would scarcely have believed that Moscow could sink so low. It is ironic that now, when unipolarity’s end is so frequently declared, Russia is struggling to try to get something it thought it already had when US primacy was at its peak. And if you had told Yeltsin that Russia would not be winning that war against a country with an economy one-tenth the size of Russia’s, he would have been all the more incredulous. The misadventure in Ukraine, moreover, has greatly undermined Russia’s long-term economic prospects, thanks to the massive wave of sanctions the West has unleashed.

But even if Russia had swiftly captured Kyiv and installed a pro-Russian government, as Putin expected, that would have had little bearing on the global distribution of power. There is no denying that the outcome of the war in Ukraine matters greatly for the future of that country’s sovereignty and the strength of the global norm against forceful land grabs. But in the narrow, cold-hearted calculus of global material power, Ukraine’s small economy—about the same size as that of Kansas—means that it ultimately matters little whether Ukraine is aligned with NATO, Russia, or neither side. Further, Ukraine is not in fact a US ally. Russia would be very unlikely to dare attack one of those. Given how the United States has reacted when Russia attacked a country that is not a US ally—funneling arms, aid, and intelligence to the Ukrainians and imposing stiff sanctions—the Kremlin surely knows that the Americans would do much more to protect an actual ally.

China’s revisionism is backed up by much more overall capability, but as with Russia, its successes are astonishingly modest in the broad sweep of history. So far, China has altered the territorial status quo only in the South China Sea, where it has built some artificial islands. But these small and exposed possessions could easily be rendered inoperative in wartime by the US military. And even if China could secure all the contested portions of the South China Sea for itself, the overall economic significance of the resources there—mainly fish—is tiny. Most of the oil and gas resources in the South China Sea lie in uncontested areas close to various countries’ shorelines.

Unless the US Navy withdraws from Asia, China’s revisionist ambitions can currently extend no farther than the first island chain—the string of Pacific archipelagoes that includes Japan, the Philippines, and Taiwan. That cannot change anytime soon: it would take decades, not years, for China to develop the full range of capabilities needed to contest the US military’s command of the commons. Also, China may not even bother to seek such a capacity. However aggravating Chinese policymakers find their rival’s behavior, US foreign policy is unlikely to engender the level of fear that motivated the costly development of Washington’s global power-projection capability during the Cold War.

For now, there is effectively only one place where China could scratch its revisionist itch: in Taiwan. China’s interest in the island is clearly growing, with Xi having declared in 2022 that “the complete reunification of the motherland must be achieved.” The prospect of a Chinese attack on Taiwan is indeed a real change from the heyday of total unipolarity, when China was too weak for anyone to worry about this scenario. But it is important to keep in mind that Beijing’s yearnings for Taiwan are a far cry from revisionist challenges of the past, such as those mounted by Japan and Germany in the first half of the twentieth century or the Soviet Union in the second; each of those countries conquered and occupied vast territory across great distances. And if China did manage to put Taiwan in its column, even the strongest proponents of the island’s strategic significance do not see it as so valuable that changing its alignment would generate a dramatic swing in the distribution of power of the kind that made multipolarity so dangerous.

What about the flourishing partnership between China and Russia? It definitely matters; it creates problems for Washington and its allies. But it holds no promise of a systemic power shift. When the aim is to balance against a superpower whose leadership and extensive alliances are deeply embedded in the status quo, the counteralliance needs to be similarly significant. On that score, Chinese-Russian relations fail the test. There is a reason the two parties do not call it a formal alliance. Apart from purchasing oil, China did little to help Russia in Ukraine during the first year of the conflict. A truly consequential partnership would involve sustained cooperation across a wide variety of areas, not shallow cooperation largely born of convenience. And even if China and Russia upgraded their relations, each is still merely a regional military power. Putting together two powers capable of regional balancing does not equate to global balancing. Achieving that would require military capabilities that Russia and China individually and collectively do not have—and cannot have anytime soon.

Rough times for revisionism

All this might seem cold comfort, given that even the limited revisionist quests of China and Russia could still spark a great-power war, with its frightening potential to go nuclear. But it is important to put the system’s stability in historical perspective. During the Cold War, each superpower feared that if all of Germany fell to the other, the global balance of power would shift decisively. (And with good reason: in 1970, West Germany’s economy was about one-quarter the size of the United States’ and two-thirds the size of the Soviet Union’s.) Because each superpower was so close to such an economically valuable object, and because the prize was literally split between them, the result was an intense security competition in which each based hundreds of thousands of troops in their half of Germany. The prospect of brinkmanship crises over Germany’s fate loomed in the background and occasionally came to the foreground, as in the 1961 crisis over the status of Berlin.

Or compare the present situation to the multipolar 1930s, when, in less than a decade, Germany went from being a disarmed, constrained power to nearly conquering all of Eurasia. But Germany was able to do so thanks to two advantages that do not exist today. First, a great power could build up substantial military projection power in only a few years back then, since the weapons systems of the day were relatively uncomplicated. Second, Germany had a geographically and economically viable option to augment its power by conquering neighboring countries. In 1939, the Nazis first added the economic resources of Czechoslovakia (around ten percent the size of Germany’s) and then Poland (17 percent). They used these victories as a springboard for more conquests in 1940, including Belgium (11 percent), the Netherlands (ten percent), and France (51 percent). China doesn’t have anything like the same opportunity. For one thing, Taiwan’s GDP is less than five percent of China’s. For another, the island is separated from the mainland by a formidable expanse of water. As the MIT research scientist Owen Cote has underscored, because China lacks command of the sea surface, it simply “cannot safeguard a properly sized, seaborne invasion force and the follow-on shipping necessary to support it during multiple transits across the 100-plus mile-wide Taiwan Straits.” Consider that the English Channel was a fifth of the width but still enough of a barrier to stop the Nazis from conquering the United Kingdom.

Japan and South Korea are the only other large economic prizes nearby, but Beijing is in no position to take a run at them militarily, either. And because Japan, South Korea, and Taiwan have economies that are knowledge-based and highly integrated with the global economy, their wealth cannot be effectively extracted through conquest. The Nazis could, for example, commandeer the Czech arms manufacturer Skoda Works to enhance the German war machine, but China could not so easily exploit the Taiwan Semiconductor Manufacturing Company. Its operation depends on employees with specialized knowledge who could flee in the event of an invasion and on a pipeline of inputs from around the globe that war would cut off.

Today’s revisionists face another obstacle: while they are confined to regional balancing, the United States can hit back globally. For instance, the United States is not meeting Russia directly on the battlefield but is instead using its global position to punish the country through a set of devastating economic sanctions and a massive flow of conventional weaponry, intelligence, and other forms of military assistance to Kyiv. The United States could likewise “go global” if China tried to take Taiwan, imposing a comprehensive naval blockade far from China’s shores to curtail its access to the global economy. Such a blockade would ravage the country’s economy (which relies greatly on technological imports and largely plays an assembly role in global production chains) while harming the US economy far less.

Because the United States has so much influence in the global economy, it can use economic levers to punish other countries without worrying much about what they might do in response. If China tried to conquer Taiwan, and the United States imposed a distant blockade on China, Beijing would certainly try to retaliate economically. But the strongest economic arrow in its quiver wouldn’t do much damage. China could, as many have feared, sell some or all of its massive holdings of US Treasury securities in an attempt to raise borrowing costs in the United States. Yet the US Federal Reserve could just purchase all the securities. As the economist Brad Setser has put it, “The US ultimately holds the high cards here: the Fed is the one actor in the world that can buy more than China can ever sell.”

Today’s international norms also hinder revisionists. That is no accident, since many of these standards of behavior were created by the United States and its allies after World War II. For example, Washington promulgated the proscription against the use of force to alter international boundaries not only to prevent major conflicts but also to lock in place the postwar status quo from which it benefited. Russia has experienced such strong pushback for invading Ukraine in part because it has so blatantly violated this norm. In norms as in other areas, the global landscape is favorable terrain for the United States and rough for revisionists.

America's choice

The political scientist Kenneth Waltz distinguished between the truly systemic feature of the distribution of capabilities, on the one hand, and the alliances that states form, on the other. Although countries could not choose how much power they had, he argued, they could pick their team. The US-centric alliance system that defines so much of international politics, now entering its eighth decade, has attained something of a structural character, but Waltz’s distinction still holds. The current international order emerged not from power alone but also from choices made by the United States and its allies—to cooperate deeply in the economic and security realms, first to contain the Soviet Union and then to advance a global order that made it easier to trade and cooperate. Their choices still matter. If they make the right ones, then bipolarity or multipolarity will remain a distant eventuality, and the partial unipolar system of today will last for decades to come.

Most consequentially, the United States should not step back from its alliances and security commitments in Europe or Asia. The United States derives significant benefits from its security leadership in these regions. If America came home, a more dangerous, unstable world would emerge. There would also be less cooperation on the global economy and other important issues that Washington cannot solve on its own.

Indeed, in the era of partial unipolarity, alliances are all the more valuable. Revisionism demands punishment, and with fewer unilateral options on the table, there is a greater need for the United States to respond in concert with its allies. Yet Washington still has substantial power to shape such cooperation. Cooperation among self-interested states can emerge without leadership, but it is more likely to do so when Washington guides the process. And American proposals frequently become the focal point around which its partners rally.

Keeping US alliances in Asia and Europe intact hardly means that Washington should sign a blank check: its friends can and should do more to properly defend themselves. Not only will they need to spend more; they will need to spend more wisely, too. US allies in Europe should increase their capacity for territorial defense in areas where the United States can do less while not trying to duplicate areas of US strength. In practice, this means focusing on the simple task of fielding more ground troops. In Asia, US allies would be wise to prioritize defensive systems and strategies, especially with respect to Taiwan. Fortunately, after more than a decade of ignoring calls to prioritize a defensive strategy for securing the island—turning it into a difficult-to-swallow “porcupine”—Taipei appears to have finally awakened to this need, thanks to Ukraine.

In economic policy, Washington should resist the temptation to always drive the hardest bargain with its allies. The best leaders have willing followers, not ones that must be coaxed or coerced. At the heart of today’s international order is an implicit pledge that has served the United States well: although the country gains certain unique benefits from its dominance of the system, it doesn’t abuse its position to extract undue returns from its allies. Maintaining this arrangement requires policies that are less protectionist than the ones pursued by either the Trump or the Biden administration. When it comes to trade, instead of thinking just about what it wants, Washington should also consider what its allies want. For most, the answer is simple: access to the US market. Accordingly, the United States should put real trade deals on the table for its partners in Asia and Europe that would lower trade barriers. Done properly, market access can be improved in ways that not only please US allies but also create enough benefits for Americans that politicians can overcome political constraints.

The United States must also resist the temptation to use its military to change the status quo. The 20-year nation-building exercise in Afghanistan and the invasion of Iraq were self-inflicted wounds. The lesson should be easy enough to remember: no occupations ever again. Any proposal to use US military force outside Asia and Europe should be deeply interrogated, and the default response should be “no.” Preventing China and Russia from changing the status quo in Asia and Europe was once relatively easy, but now it is a full-time job. That is where the US military’s focus should lie.

Ultimately, the world in the age of partial unipolarity retains many of the characteristics it exhibited in the age of total unipolarity, just in modified form. International norms and institutions still constrain revisionists, but these states are more willing to challenge them. The United States still has command of the commons and a unique capacity to project military power across the globe, but China has created a fiercely contested zone near its shores. The United States still possesses vast economic leverage, but it has a greater need to act in concert with its allies to make sanctions effective. It still has a unique leadership capacity for promoting cooperation, but its scope for unilateral action is reduced. Yes, America faces limits it did not face right after the Soviet Union’s collapse. But the myth of multipolarity obscures just how much power it still has.