A distinct and distinctive period in the history of American foreign policy, one spanning the two decades following the conclusion of the Cold War, has come to an end. A new era has begun. The international conditions in which the American government must conduct its relations with other countries, and that will therefore shape its foreign policy, have changed. The United States finds itself in a new world, which raises three questions: How was the post-Cold War era distinctive? How and why did it end? And what is the new agenda for the foreign policy of the United States?

The Post-Cold War Peace

The era following the Cold War constituted the fourth distinct period in the history of America’s relations with other countries. In the first, from 1789 to 1898, the nation’s focus was largely inward, extending its control across North America and settling its most divisive issue in a bloody civil war. During the second, between 1898 and 1945, the United States became one of several great powers, acquiring imperial possessions and taking a prominent part in two world wars. From 1945 to the end of the Cold War, America was one of only two global superpowers and the chief organizer and protector of the security and economic orders of the Western world. The post-Cold War era began in 1993 and had concluded by the end of 2014.¹

In the wake of the Cold War something unique in modern American history and rare in the historical experience of any great power occurred: The United States faced no serious threats from other powerful states. The dominant, defining feature of the post-Cold War era, notwithstanding the eruptions of terrorism, was peace. It was a peace that arose not only from the absence of war but from the absence of the threat of war, of urgent preparations for war, and of serious thoughts of war among the most powerful political leaders on the planet. It arose from the absence of what is sometimes called security competition, or power politics—that is, political and military rivalries among the strongest countries.

The absence of security competition gave the United States an unusually wide range of choices in designing and carrying out its foreign policies. It chose what is misleadingly called “nation-building.” The United States in fact attempted, all over the world, two different although closely related tasks: nation building—that is, creating a sense of national community among disparate peoples; and state-building—establishing the institutions of modern government such as courts, legislatures, and competent administrative agencies. Free to ignore the standard business of foreign policy—responding to the international security-relevant behavior of other governments—America chose to try to transform the way governments behaved toward those they governed.

These missions of transformation preoccupied the administrations of Bill Clinton, George W. Bush, and Barack Obama. They characterized post-Cold War American policy toward China, Russia, Somalia, Haiti, Bosnia, Kosovo, Afghanistan, Iraq, and the wider Arab world. To be sure, in none of these places did the United States deliberately embark on protracted efforts at nation- and state-building. In its policies toward China and Russia, the Clinton Administration was mainly responding to domestic pressures in the United States. In conducting military operations in Somalia, Haiti, Bosnia, and Kosovo, Clinton Administration officials sought to protect the people living in those places from the depredations of local authorities. The Administration of George W. Bush launched the wars in Afghanistan and Iraq for the most traditional of reasons: to defend American security in response to a direct attack on the United States. In each, however, the American government eventually found itself trying to transform local politics and economics in those two countries and others besides.

In this sense the terrorist attacks on New York City and Washington, D.C. on September 11, 2001, did not mark a watershed in the history of American foreign policy. True, the attacks had a profound impact, leading to three wars—the War on Terror and the wars in Afghanistan and Iraq—that the United States would not otherwise have waged. Still, the last two of them turned into missions of transformation.

These far-flung missions shared a common feature: They all failed. The United States did not succeed in getting China to protect human rights, or in constructing smoothly functioning free markets or genuinely representative political institutions in Russia. It did not succeed in installing well-run, widely accepted governments in Somalia, Haiti, Bosnia, or Kosovo. It did not turn Afghanistan or Iraq into tolerant, effectively administered countries. It did not bring democracy to the Middle East or harmony between Israelis and Arabs.

It did not achieve these goals because the goals were not achievable with the available tools. The tools of foreign policy are guns, money, and words implying that either or both of the former will be used. These can and do affect what other countries do outside their own borders; they are far less effective in shaping what other countries are like within those borders.

In fact, in every case, mission failure stemmed from the absence of the social conditions necessary to support the public institutions and practices that the United States hoped to install. It was not and is not within the power of the United States, or of any other country, to create these conditions abroad. The necessary conditions do get created, and nations and modern states do get built, but this has to be done by the people of the countries where successful nation- and state-building take place.

By the end of 2014 the post-Cold War era, the era of American missions of transformation, had come to an end. It ended not only, perhaps not even principally, because the missions failed. It ended as well because the world changed in ways that presented the United States with more pressing as well as more familiar tasks beyond its borders. A quarter-century after its disappearance, the historically normal defining condition of international politics—security competition—had returned. Once again the United States faced international threats, threats not as serious as those the country had had to confront during World War II and the Cold War, but substantial challenges to American interests nonetheless.

The United States could thus no longer afford to concentrate on promoting its values through missions of transformation because it had, as in the past, to protect its interests. By the end of 2014 power politics had returned to three crucial regions of the world in the form of ambitious, aggressive countries seeking regional dominance. The proper business of American foreign policy had become resisting the designs of Russia in Europe, of China in East Asia, and of Iran in the Middle East.

Russia and Europe

In 2014 Russia resumed its national habit of invading neighboring countries. Russian forces seized the Crimean peninsula from Ukraine and then attacked and occupied two of Ukraine’s eastern provinces, which had large populations of ethnic Russians. No comparable invasion, conquest, and occupation of part of another country had taken place in Europe since Nazi Germany’s eastward thrust in the early years of World War II.

The Russian assaults had multiple causes. The members of the Russian political elite had a proprietary attitude toward former Soviet republics that had become independent countries, which it called, collectively, the Near Abroad. This attitude was especially pronounced toward Ukraine, which had belonged to a Russian-dominated state since the 18^th century. When a Ukrainian President aligned with Russia was unseated by a largely peaceful popular uprising, the Russian government considered itself justified in intervening for the purpose of discrediting and crippling the new and far less Russia-friendly regime.

In addition, members of the Russian elite resented the steep decline in international status they and their country had suffered with the disintegration of the Soviet Union and sought ways to make Russia appear powerful, or at least important, again. The invasion of Ukraine served this purpose.

The nature of the Russian regime also had a great deal to do with the invasion. The Russian leader, Vladimir Putin, presided over an autocracy whose chief purpose seemed to be enriching him and his cronies, largely by diverting to them a large part of the revenues from the sale of the country’s oil and natural gas.² If Ukraine succeeded in transforming itself into a democracy, which was the stated goal of the new government, then this would provide, next door, an alternative model to the one Putin had established. The Russian people might well find such a model more attractive than the system he had imposed on them. Putin apparently decided that he could not risk such a development.

Although a dictatorship, the Russian government required public support, or at least acceptance, which had two sources. In the first decade of the 21^st century the sharp rise in the price of oil vastly increased Russia’s national income, some of which reached the Russian public. Russians thus became more prosperous and, although he had had almost nothing to do with it, they credited that prosperity to Putin. Besides material improvement the regime relied on nationalist sentiment to bolster its support among the Russian people. Putin presented himself as the champion of Russian interests against an implacably hostile West, and especially a virulently hostile United States. As the price of oil fell, and with it the Russian standard of living, Putin sought to compensate with ever more strident nationalist appeals. The invasion of Ukraine served that purpose as well.

Although hardly an implacable enemy of Russia, the West, and the United States, did bear some responsibility for the course of Russian foreign policy. In the mid-1990s they expanded their Cold War military alliance, the North Atlantic Treaty Organization (NATO), eastward to include 12 formerly communist countries. They did this despite oral promises by Western officials to their Russian counterparts not to do so and over the opposition of Russians across the political spectrum, including pro-Western liberals whose standing with their countrymen NATO expansion undercut.

Its sponsors justified expansion on the grounds that it would promote democracy in the new member countries. This was doubly nonsensical. The East European countries did not need NATO membership to become democracies; they were eager to adopt Western political and economic systems. Moreover, if NATO membership did promote democratic governance—a proposition for which its proponents produced no evidence—the most important formerly communist country to bring into the alliance, the one where democratic principles and institutions were most at risk and the stakes for the West were highest, was Russia itself, but it was made clear to Russian officials that their country would not receive an invitation to join.

The most important American motive for expansion was domestic American politics, specifically Bill Clinton’s desire to win the support of American voters with family roots in the East European countries being invited to join NATO in his 1996 campaign for re-election. The expansion of the alliance, in concert with subsequent initiatives such as the wars in Bosnia, Kosovo, and Iraq and the unilateral abrogation of the 1972 Soviet-American treaty effectively banning systems of ballistic missile defense, made opposition to the West the core of Russian foreign policy. It created a reservoir of support for anti-Western measures upon which Vladimir Putin, who falsely portrayed the overthrow of the Ukrainian President as the result of a Western plot, drew for support for the invasion of Russia’s neighbor. In the end, the expansion of NATO over their objections taught Russians two lessons that it was not remotely in the interests of the West for them to learn: that Western promises were not to be trusted; and that the West would take advantage of a weak and accommodating Russia.

Instead of expanding NATO, the United States and its allies could have found ways to include Russia in a new European security system, the foundations of which already existed.³ This would not necessarily have ensured the establishment of political democracy there, but it would surely have affected Russian foreign policy. It would have reduced both the leadership’s incentives for aggression and the popular support on which it could count for aggressive policies. Without NATO expansion Putin would not have found it as easy as he did to present the conflict in Ukraine as defensively motivated rather than what it actually was: a war of aggression. Including Russia in a new European security order would also have given the West more influence over Russian foreign policy than excluding it provided.

By the end of 2014 it was both too late and too early for the kinds of policies that, had they been adopted in the 1990s, could have prevented the invasion of Ukraine: too late because its acts of aggression and its authoritarian rule had made the Putin regime ineligible for membership in Western institutions; too early because, for this very reason, reversing the error of NATO expansion and welcoming Russia into a pan-European security system can only take place with a new, less dictatorial, less aggressive government in place in Moscow, and regime change there does not appear imminent.

China and Asia

In East Asia, China—like Russia in Europe—initiated policies that challenged the political and military status quo and thereby threatened American interests. During the post-Cold War period China began to devote ever more of its rapidly growing economic output to its military. The Chinese investment in naval forces and the construction of a major naval base on Hainan Island off its south coast had disturbing implications for China’s Asian neighbors and for the United States. The Chinese naval program was designed to give the country the means to project power well into the East and South China Seas, and even farther. Because the American Navy dominated the Western Pacific, as it had since World War II, the build-up of China’s maritime force propelled it toward a direct conflict with the United States.

To accompany its growing naval prowess China adopted increasingly aggressive declaratory policies concerning the waters off its coast and to its south. It asserted that the vessels of other countries, including military vessels, required permission operate in any country’s 200-mile “Exclusive Economic Zone,” an assertion disputed by the United States and most other countries, who favored free passage in all such zones. China was also at odds with Japan over the ownership of the five small, uninhabited Senkaku Islands in the East China Sea. To the south, Chinese officials defined their own territorial waters in breathtakingly expansive fashion. The line that China published to demarcate its claims reached as far south as Indonesia. It conflicted with the maritime claims not only of Indonesia but of Vietnam, the Philippines, and Malaysia, as well. Chinese statements designated this vast expanse of maritime acreage a “core interest” of China, placing it in the same category as Tibet and Taiwan, two places over which the regime had expressed its willingness to go to war. To reinforce the point, China began building artificial islands in the South China Sea complete with airstrips capable of handling military aircraft.

The American-centered financial crisis of 2008 and the deep global recession that followed contributed to what appeared to be a Chinese bid for mastery in the western Pacific. The Chinese saw these events as signs that American power and global primacy were waning. Also contributing to China’s new assertiveness was the assumption of supreme power in the Chinese Communist Party, in 2012, of Xi Jinping, who advocated the regional and global expansion of Chinese power and influence more openly and forcefully than his post-Maoist predecessors.

Ultimately, however, China’s challenge to the American-dominated post-Cold War political and economic orders in East Asia emerged from a combination of surging economic growth and deeply rooted nationalist sentiment. As their country became richer, the conviction of the Chinese that it should be powerful as well came increasingly to inform its policies toward its neighbors as well as the United States.

The Chinese were conscious of their long history not only as a great civilization but also as the dominant power in East Asia. The aspiration to resume that role had deep roots in Chinese political culture, which inspired the Chinese desire to translate their country’s economic success into wider political influence. Also pushing China toward an aggressive approach beyond its borders was a deeply embedded sense of grievance against the rest of the world. The Chinese communist authorities emphasized the “century of humiliation”—from British bullying in the first Opium War in 1839 to the communist consolidation of power 110 years later—that China had experienced at the hands of outside powers. The Chinese saw themselves as victims of the West and of Japan. This colored their 21^st-century view of the United States, which Chinese officials frequently accused of following the long-established Western practice of working to reduce and contain China’s power.

While China’s growth led to a more aggressive foreign policy, contrary to Chinese accusations, the United States never tried to retard, much less prevent, its economic advance. Such an effort would have failed. Other countries, in Europe and in Asia, would not have taken part in a campaign to set back the Chinese economy. In the United States businesses and consumers, both of whom benefitted from China’s growth, would not have been happy with such a policy had the American government proposed it—which it never did.

Instead, American officials, through the three post-Cold War presidential administrations, expressed confidence that, as it became more powerful, China would maintain peaceful, cooperative relations with the rest of the world. Economic growth based on free markets, Americans believed, would make Chinese politics more open, less repressive, and more democratic. The more democratic a country’s political system becomes, they also believed, the more peaceful its foreign policies will be.

Up to a point this optimistic assessment of China’s future proved accurate. As the country’s remarkable economic growth continued, Chinese citizens did secure greater freedom. They could travel abroad, own property, start businesses, and engage in open public discussion of a wide range of subjects, none of which had been possible during the Maoist era. China did not, however, become a democracy; and as it grew richer its foreign policies, contrary to American expectations, became more aggressive.

By the end of 2014 the ruling Chinese Communist Party faced a number of serious challenges, not least a decline in the extraordinary double-digit rates of economic growth the country had maintained for three decades. To the extent that it could not deliver the kind of growth the Chinese public had come to expect, the regime had a powerful motive to emphasize, and act on, the national aspiration to greater power and influence beyond its borders. Like Vladimir Putin in Russia, Xi Jinping had an incentive to engage in strident nationalist rhetoric and pursue overtly nationalist policies. In that way he could hope to compensate for reduced prosperity, for the purpose of sustaining public support, or at least tolerance, for his regime. That, in turn, would bring China increasingly into conflict with its Asian neighbors and with the United States.

Iran and the Middle East

In the Middle East, the third region of the world where a post-Cold War peace—admittedly a shaky one—gave way to an environment that included threats to American interests, the United States had neither powerful, stable, long-term allies such as Japan and Korea in East Asia, nor a history of successful nuclear deterrence, as in Europe. There the country most responsible for bringing back security challenges was the Islamic Republic of Iran.

Iran’s ruling clergy presided over an aggressive foreign policy aimed, ultimately, at dominating the region, which threatened America’s three principal interests: stopping nuclear proliferation, preventing a single country from dominating the Middle East, and ensuring the continuing flow of Middle Eastern oil to Europe and Asia. (The United States also has a continuing interest in Israel’s security, but, unlike most American allies, Israel can and will defend itself.)

Iran’s aspirations did not begin in 2014. They date from the revolution of 1979, which brought the radical clerics to power in Tehran with a commitment to spreading their brand of theocratic politics and their country’s influence as far as possible. The passage of time contributed to the country’s emergence as a serious threat to the United States. The regime worked steadily, and clandestinely, to acquire nuclear weapons. By 2014 these ongoing efforts were approaching fruition.⁴

In addition, several American policies strengthened, albeit entirely unintentionally, the Iranian regime. The Afghan Taliban, Saddam Hussein, and the Islamic State in Iraq and Syria, each of them Sunni Muslim, were all bitter adversaries of Shi’a Iran. The United States conducted wars against all of them, which worked to Iran’s advantage. Above all, Iran benefitted from the upheavals in the Middle East that began in 2003 when the United States deposed Saddam Hussein. The disorder spread across the region as the result of the “Arab Spring,” which led in Egypt to the downfall of one former general, a short period with the fundamentalist Muslim Brotherhood in power, and then the re-imposition of another former general as President, to bloody civil wars in Syria, Libya, and Yemen, and to the forcible creation of a harsh, terror-supporting, fundamentalist “Islamic State” in parts of Syria and Iraq.

These upheavals triggered a regional civil war between Islam’s two major sects, Sunni and Shi‘a, which by 2014 dominated the politics of the Middle East. In that sectarian conflict the Iran-led Shi‘a coalition, although numerically inferior to its Sunni rivals, gained the upper hand. The Shi‘a bloc proved to be more cohesive politically and, on the whole, more effective militarily than its Sunni adversary, and was fortified by military support from Russia in Syria.

Burned by its failed mission in Iraq, the United States under the Obama Administration largely steered clear of the turmoil across the Middle East. American forces did participate in the overthrow of the Qaddafi regime in Libya and actively oppose the Islamic State, whose campaign of terrorism threatened individual Americans, but not Iran, which posed a far greater threat to important American interests. Of those three interests, the American government attempted to deal with the first, nuclear proliferation, through an agreement concluded in 2015 that, if the Iranian regime observed its terms, would delay but not stop the Iranian acquisition of nuclear weapons. The U.S. Navy continued its longstanding patrolling in the Mediterranean and the Indian Ocean, which provided a measure of protection for the shipment of oil from the region to the oil-importing countries of Europe and Asia. As for the third interest, thwarting Iran’s bid for hegemony in the Middle East, the United States developed no apparent strategy for accomplishing this goal.

The New World

The first U.S. President to have to cope with the new world that the return of security competition created was Barack Obama. He did not forge—or try to forge—a new foreign policy appropriate to America’s changed circumstances. Indeed, he showed few signs of recognizing the changes that the foreign policies of Russia, China, and Iran had brought about.

Obama came to office with a mandate to be what Steven Sestanovich has called a “retrenchment president,” one elected to reduce America’s global activities.⁵ Unwinding what had become the unpopular American interventions in Iraq and Afghanistan and avoiding other, similar commitments dominated his foreign-policy agenda. During his first term he did withdraw all American troops from Iraq and most of them from Afghanistan.

He brought to office some personal and implausible ideas about improving America’s position in the world, which led to initiatives that, predictably, failed. He embraced the goal of abolishing all nuclear weapons, but made no progress toward achieving it. He gave a speech in Cairo directed at the Islamic world that was intended to improve Muslims’ views of the United States, but this, too, did not come to pass. He launched conciliatory approaches toward governments hostile to America. These initiatives did not transform relations with Russia or North Korea. While Obama did secure an agreement to limit Iran’s nuclear weapons program, that agreement did not, as he alternately hoped and expected, cause a change in the Islamic Republic’s aggressive, anti-American foreign policy.

Obama did announce a “pivot to Asia” in recognition of the growing importance for the United States of the Asia-Pacific region and of growing concern among China’s neighbors about the Chinese role there. He did not, however, propose a new doctrine or set of principles to guide American foreign policy in a world to which power politics had been restored. The closest thing to an Obama Doctrine to emerge from his presidency was his maxim “Don’t do stupid stuff,” a good idea, certainly, but of limited utility in deciding how to respond to Russia, China, and Iran.⁶

Obama did not try to design a new foreign policy at least in part because he came under no public pressure to do so. No single, dramatic event, like the attacks on Pearl Harbor in 1941 and on New York and Washington, DC, sixty years later, galvanized the American public by making clear to it that the United States confronted a new, more dangerous international environment. Moreover, the President himself did not seem particularly well suited, by temperament or experience, to conduct the affairs of state in a world dominated by security competition. His rhetoric suggested that he regarded harmony, not rivalry, as not only the desirable but also the achievable condition of international politics, and the use of American power more often than not counterproductive. In addition, he had spent his entire political career, and almost his entire adult life, in the unusually peaceful circumstances of the post-Cold War era. He had not had to confront the choices, or carry out the policies, that power politics imposes.

If it is alien to America’s 44^th President, however, the world after the post-Cold War era has a familiar look to anyone older than he. Security competition, not its absence, has been the norm in international history. Barack Obama’s elders all experienced a period when considerations of power and security dominated American foreign policy, the period of the Cold War. Yet the new era of foreign policy also differs from the one during which the United States opposed the Soviet Union, its clients, and its satellites in several ways. The Cold War was a global struggle against an adversary with a presence in every part of the world: Europe, Asia, Latin America and Africa were all battlegrounds in the struggle against communism. Now, however, the United States faces distinct regional challenges rather than a single global one. Although they display some affinity for one another, Russia, China, and Iran threaten American interests only in Europe, Asia, and the Middle East respectively, and they hardly form a unified bloc.

Nor, unlike the Cold War, do the current challenges stem from a hostile, aggressive ideology with universal pretensions. Iran does have an official, Islamist political creed that it seeks to spread but it is aimed chiefly at other Muslims. For still-officially communist China, nationalism, not a set of universally applicable ideas, fuels its regional ambitions, as it does those of no-longer-communist Russia.

During the Cold War, to cite two final differences, Russia had far more power than it does now, whereas China had far less. And unlike the first half of the Cold-War era, Russia and China are neither ideological partners nor military allies; but, unlike the second half of that period, they are not adversaries whom the United States can play off against each other.

Still, in the current period the appropriate principal American objective is the same as it was during the rivalry with the Soviet Union: deterrence—of Russia in Europe, of China in Asia, and of Iran in the Middle East. During the Cold War, particularly in Europe, the policy of deterrence was straightforward. The American government declared, publicly and repeatedly, that it would regard a communist attack on its European allies as an attack on the United States itself and that American troops would therefore fight alongside their European counterparts. In the second decade of the 21^st century, however, deterrence has become more complicated.

China’s maritime initiatives qualify as aggressive, but not as unambiguous acts of aggression. China has not yet attacked the territory of any other sovereign state. Moreover, the Asian countries that Chinese assertiveness has alarmed, and indeed the United States itself, have deep economic ties to China that they do not want to jeopardize. All of them, therefore, shy away from the kind of explicit identification of China as an adversary, and concrete commitment to taking military action against it in specific circumstances, that the United States and its allies undertook toward the Soviet Union during the Cold War.

Unlike in Asia, in Europe the United States belongs to a formal military alliance, NATO, which has already taken measures—increasing its military presence in the Baltic countries, for example—in response to the Russian assault on Ukraine. Even there, however, European trade with and investment in Russia, and above all their dependence on Russian energy, have made the Europeans reluctant to make the deterrence of Russia as clear and unambiguous a policy as was the deterrence of its Soviet predecessor. With Iran, the urgent priority is to deter not the use of force but rather the acquisition of nuclear weapons.⁷

As was the case with the Soviet Union during the Cold War, for the purpose of deterring China, Russia, and Iran there is strength in numbers. The United States plays an indispensable role in all three regions but also needs, and has, allies in each of them. Moreover, these alliances, in most cases, have deep roots, dating back to the Cold War. Even in the Middle East, while the Sunni countries opposed to Iran hardly constitute a cohesive bloc, they do contribute in various ways, if often only modestly, to containing the Islamic Republic.

Coalitions require coalition maintenance on the part of their leaders because their members inevitably have different as well as common interests. Harmony seldom reigns. Every alliance is, to some degree, an exercise in mutual recrimination. Enhancing the difficulty for the United States in managing the coalitions to check China, Russia, and Iran is a newly prominent feature of American domestic politics: resentment of the nation’s allies. Both President Obama and the prospective Republican presidential nominee in 2016, Donald Trump, have denounced them as “free riders” who pay less than their fair shares of the costs of carrying out policies for which they, along with the United States, are responsible. The apparent resonance of this criticism with the American public arises from its frustration with the expensive interventions in Afghanistan and Iraq and with economic conditions at home. It does not stem from an informed assessment of the contributions to the common defense made by the country’s European, Asian, and Middle Eastern allies, or a considered evaluation of the benefits to the United States of those contributions.

Nonetheless, such resentment has become a significant force in American public life. In order to cope with the conditions of the new world in which the United States finds itself—in order, that is, successfully to deter China, Russia, and Iran—the next American President must first forge a consensus in the United States in favor of such policies, including a consensus on the role of the nation’s allies. In conducting American foreign policy in this new-old world of power politics, that may prove to be the hardest task of all.