An American Strategy for a Multipolar World

Editor’s Note: The New Visions for Grand Strategy Project brought scholars from across the political and ideological spectrum to discuss what the future has in store for the United States in the world. The editors of this series sought to foster a lively debate about America’s global role and strategic futures. Each author in this collection speaks for himself or herself alone, and their views do not reflect the official positions of the Henry L. Stimson Center, or of their own employers. Zack Cooper is a senior fellow at the American Enterprise Institute and a lecturer at Princeton University.

By Emma Ashford, Senior Fellow, New Visions for Grand Strategy Project

U.S. grand strategy has been remarkably consistent over the last century. But the American people and their elected representatives no longer appear willing to dedicate the resources required to uphold some key elements of longstanding U.S. foreign policy. Gone are the days when President John F. Kennedy could promise that the United States would “bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and success of liberty.”¹ In its place is a narrower definition of American interests and a fundamental rethinking of the United States’ place in the world. This essay argues that bringing American ends and means back into balance requires U.S. leaders to not only acknowledge the emergence of multipolarity, but to fully embrace it.

Shifting American Views

President Donald Trump is often credited with crystallizing and capitalizing on shifts in American public opinion about international engagement. Yet, a combination of structural explanations provides a more convincing explanation for the American public’s reconsideration of U.S. grand strategy.

First, the United States is no longer a rising power — instead, America appears to have reached its apex and is on the downslope of Pax Americana. Trump’s “make-America-great-again” motto acknowledges a degree of decline, even if it simultaneously holds out hope that this trend can be reversed. Secretary of State Marco Rubio has argued, “It’s not normal for the world to simply have a unipolar power…that was an anomaly. It was a product of the end of the Cold War, but eventually you were going to reach back to a point where you had a multipolar world, multi-great powers in different parts of the planet. We face that now.”² As I chronicle in Tides of Fortune, the perception of relative decline changes countries’ national objectives by making them more defensive and shrinking their geographic focus.³ Not surprisingly, many Americans are doing exactly this today.

Second, many young people question America’s ability to bring about positive outcomes in the world. The generations of Americans that experienced World War I, World War II, or even the Cold War are passing from the scene. In their place is a generation that grew up with American failures in Afghanistan and Iraq, among other locales. They question the U.S. government’s ability to positively influence global security and international development, particularly with foreign assistance. These factors are driving a rethinking about spending on both military and nonmilitary instruments because many are deeply skeptical of arguments that without U.S. engagement, the world will become a more dangerous place.

Third, U.S. resources are stretched at exactly the moment when new threats are rising. In 2024, RAND’s Commission on the National Defense Strategy suggested that “the severity of the threats…will require spending that puts defense and other components of national security on a glide path to support efforts commensurate with the U.S. national effort seen during the Cold War.”⁴ Yet, U.S. defense spending as a percentage of gross domestic product remains lower than it has been for most of the last century, and the American people (via the U.S. Congress) have proven unwilling to dedicate more resources to defense.⁵ America’s rising debt burden and the public’s growing skepticism of international engagement are creating a “Lippmann Gap.”⁶ American ends and means no longer appear to be balanced.⁷

Although many in the national security community hope to reverse these trends and convince the American people of the wisdom of international engagement, these constraints are likely to continue for the foreseeable future. Indeed, there is reason to believe that these dynamics could intensify as U.S. debt increases and the memory of effective U.S. international interventions fades in the minds of the American people. As U.S. circumstances have changed, many members of the American public have become frustrated — they perceive that experts in Washington are out of touch with the views held by many people in the rest of the country. Therefore, it is no longer sufficient for the national security community in Washington to make the case for renewed support for international engagement. U.S. policymakers need to adapt American grand strategy to the missions and burdens that the American people are willing to accept today.

Addressing Strategic Insolvency

How might U.S. leaders bring American ends and means back into alignment? One possibility is that an American president who can trumpet the value of international engagement could take the helm. President Ronald Reagan is perhaps the best example of a leader who was able to win public support for major increases in spending on national security priorities without a precipitating crisis.⁸ But as noted above, today’s circumstances are quite different from those over four decades ago; the current global situation could constrain even the most gifted orators. Moreover, a long-term change in U.S. international engagement would require sustained investment over many years, which is probably beyond the capability of any single leader, no matter how effective.

A more dire possibility is that a conflict could erupt that convinces the American people that they need to devote more time, attention, and resources to national security. The United States has been lulled into a sense of false security repeatedly in its history, only to be jolted awake by an attack from overseas. This was the case with the attack on Pearl Harbor, the invasion of South Korea, and the September 11 attacks. A stunning surprise attack of this sort could force Americans to rethink their approach to national security and increase the resources that they are willing to dedicate to overseas missions. Yet, American leaders should not hope for or plan around such a dire scenario.

In short, Washington cannot assume that an atypical leader or an external event will resolve U.S. strategic insolvency. American officials should instead adjust their desired outcomes to meet the means appropriated by Congress. Acknowledging this reality will frustrate critics who will claim that the national security community should set objectives and then win the support necessary to achieve them, rather than the other way around. In an ideal world, this is true. But the reality is that those who believe deeply in international engagement and the need for additional defense outlays have been unable to convince many of the American people of the wisdom of our approaches. Therefore, Americans would be wise to heed advice often attributed to Winston Churchill: “We have run out of money; now we have to think.”

Thinking about a new American strategy should begin by doing a fresh assessment of the world that exists today. Two components are critical: 1) understanding shifts in the international system and 2) understanding shifts in U.S. domestic willingness to address these challenges. The first component is best accomplished with a top-down review of changes in international politics, while the second requires a bottom-up rethinking of American attitudes toward international engagement. Each is addressed separately below.

A Fragmented Multipolar World

International relations experts and political leaders are fond of saying that the world is at an inflection point. The question, however, is not whether the world is changing, but how. The central changes in the world today derive from one factor: the emergence of multipolarity. This, in turn, causes a series of other shifts in international politics that are reshaping dynamics in the economic, military, and technological arenas.

The central driver of multipolarity is the rapid rise of a number of new powers, including China, India, Indonesia, Brazil, and others.⁹ As the economic prospects of these populous countries have risen, they are catapulting past many of the world’s more established economies. By 2050, one analysis suggests that emerging markets will grow twice as fast as the advanced economies of the G-7.¹⁰ Meanwhile, many of the world’s advanced industrial economies (as well as China) are aging rapidly, with a political economist, Nick Eberstadt, noting that “[the] overwhelming majority of the world’s [gross domestic product] GDP today is generated by countries that will find themselves in depopulation a generation from now.”¹¹ In purchasing power parity terms, some experts project that China and India will surpass the United States in gross national product, while Brazil, Indonesia and Mexico surpass Germany, Japan, and the United Kingdom. Simultaneously, another group of rising powers — led by Nigeria, the Philippines, and Vietnam — is expected to vault into the world’s top 20 economies. Advances in artificial intelligence and other technologies could slow down these changes, or accelerate them, depending on where innovation occurs and how AI is proliferated and exploited around the world.

Ironically, the United States’ own actions are accelerating this shift toward multipolarity. The era of American global primacy was not going to last forever, but its downfall has been accelerated by leaders in Washington. As John Ikenberry has long argued, U.S. policies in the aftermath of World War II were designed to sacrifice some of America’s short-term power in order to lock in long-term U.S. influence.¹² Washington built international institutions — the United Nations and the North Atlantic Treaty Organization (NATO) alliance in Europe, as well as bilateral alliances in Asia, the World Trade Organization, the International Monetary Fund, the World Bank, and other institutions — that would lock in American power long after the United States started to decline. Although practiced imperfectly, this strategy decreased balancing behavior among many of the world’s great powers and incentivized countries to continue to cooperate with the United States.

Today, however, the United States has not only overlooked the value of these institutions but actively sought to undermine some of them. In so doing, it has accelerated balancing behavior by many of its traditional allies. Although staving off multipolarity would probably have been impossible, its advent could have been slowed if U.S. leaders had convinced their foreign counterparts that Pax Americana remained beneficial to them. Many recent U.S. administrations have tested the confidence of international partners, including everything from George W. Bush’s invasion of Iraq to Democrats’ unwillingness to embrace new trade deals. But the Trump administration’s focus on “America First” and allied burden sharing has dramatically accelerated the willingness and ability of traditional U.S. allies to develop independent capabilities and become separate poles in the international system.¹³ In the short term, this may be beneficial to the United States by more equitably distributing the responsibilities of international leaders. Yet, in the long term, this will effectively undermine U.S. power and influence, leading to a more complex and less orderly international system.

A multipolar world is now unavoidable, with legacy powers increasingly accompanied by a number of rising powers, but this multipolarity is also highly uneven. Some regions and subregions are clearly multipolar, while others continue to look unipolar or bipolar, such as North America and Northeast Asia, respectively. Similarly, leadership on functional issues is diverging, with different countries leading in different sectors. The Netherlands, for example, is a vital player on advanced semiconductors, while several Gulf states are investing heavily in infrastructure for AI and quantum computing. Leadership in these and other technologies is more diversified than ever. As a result, this is a much more complex system than the multipolar dynamic that existed in Europe after the Congress of Vienna (1814-1815). Today’s multipolar system is highly fragmented along regional and functional lines. America remains the strongest of the legacy powers, and China is the strongest of the rising powers, but this belies incredible complexity throughout the system that is emerging.

An Inward-Looking United States

The American people have been willing to accept the burden of international leadership for roughly 80 years, but today attitudes are shifting. Polling shows that 52% of Americans now say the United States “should pay less attention to problems overseas and concentrate on problems here at home.”¹⁴ This includes 67% of Republicans and 58% of those under the age of 50. Meanwhile, 52% of Americans report that U.S. influence in the world has been “getting weaker” in recent years. This is a dire set of assessments about the United States’ willingness to engage in the world.

And yet, two-thirds of Americans report that they still want the United States to take a “leading” or “major” role in the world.¹⁵ This is not an isolationist America, but rather a public calling for more attention to domestic over international issues. The public seems to want the United States to continue its international leadership, but to do so at a lower cost. There are growing partisan differences, however, regarding which areas should be of greatest concern to Washington. Republicans identify China as their top threat, by a significant margin.¹⁶ Democrats are more divided, with Russia currently listed a bit higher than China in their order of concerns. The two parties also increasingly have different views on the importance of everything from climate to support for Israel.

These polls suggest that going forward, the logic of American engagement should rest on several principles. First, U.S. resourcing for international engagement — both military and nonmilitary — is unlikely to increase, barring a crisis. Second, Washington should ask its allies and partners to do more because the U.S. public is questioning whether the burden of global leadership is worth the cost. Third, U.S. leaders will need to focus on managing threats from China, and to a lesser degree Russia, because those are consistently listed as the top international concerns for most Americans.

Embracing Multipolarity

Pessimists rightly note that the combination of a more inward-looking United States and a more contested international environment creates the conditions for a more contested world. Senior Fellow at the Council on Foreign Relations Rebecca Lissner and Mira Rapp-Hooper, a partner at The Asia Group, have therefore expressed concern that the United States is absent at the creation of a new world order.¹⁷ Proactively embracing multipolarity could allow the United States to continue to play a major role in the world, while shifting some of the burden of international leadership to other countries. The question is how to best execute this shift in strategy.

The United States will need to decide where it must expend resources and where it can accept risk. This requires setting priorities because the United States is seriously resource-constrained for the first time in decades.¹⁸ Leaders in Washington should scale back U.S. goals in some areas, lest the mismatch between objectives and capabilities worsen. But they should also have a clear strategy for devolving power and leadership in the areas that the United States vacates, in order to minimize the damage done to U.S. interests by any power vacuums created as a result of partial U.S. disengagement.

One approach for devolving regional influence is to empower a regional state. The Vice President for Research and Studies at the Center for Strategic and Budgetary Assessments Evan Montgomery has demonstrated that this strategy can be successful, particularly when a global power’s interests align with those of one or more regional powers.¹⁹ Another option is for the United States to maintain its leadership role but narrow the conditions of its engagement. This could include building issue-specific coalitions to pursue manageable objectives. A coalition on critical mineral processing and production outside of China, such as the Minerals Security Partnership, would be particularly advantageous at this time. Maintaining regional primacy or dominance is unlikely to be successful, but these types of more limited ends might be achievable. These strategies suggest that outright disengagement may be less advantageous than thoughtful rebalancing of resources that maintains some influence in key regions and countries.

Regional Tradeoffs

Which regions are most critical to U.S. security and prosperity, and which regions are of secondary or tertiary concern? Throughout the last century, the answer to this question revolved around the idea that the most critical regions of the world were those that could provide a jumping-off point for another great power to attack the U.S. homeland. To that end, U.S. strategy sought to prevent the rise of a hostile hegemon on the Eurasian landmass.

Today there is only one potential threat of this sort on the horizon: China. Russia is a serious threat, but it is struggling to conquer a portion of Ukraine, so it cannot pose an existential threat to the U.S. homeland. Iran, North Korea, and other smaller players are more spoilers than existential concerns. This does not imply that the United States should withdraw from Europe, the Middle East, or the Korean Peninsula. But it does suggest that Washington would be wise to rely more on its partners in those areas in order to refocus some attention and resources on the challenge from China. To that end, an honest reassessment of Washington’s regional strategies should rest upon five principles.

First, the United States should shift more attention and resources to Asia. As the most populous region of the world, and a rapidly growing economic and innovation hub, security in Asia remains vital to U.S. prosperity. America’s allies and partners in Asia are not large enough to balance China on their own, so U.S. engagement is vital to regional security. Owing to the basic disparities in power, Asia is the only place in the world where U.S. allies and partners are not capable of managing regional security without U.S. involvement. Therefore, the United States truly is the indispensable nation in Asia, since any disengagement by Washington would permit Beijing to assert hegemony across much of the region. Nonetheless, the United States does not need to do everything in Asia. It can help organize key allies and partners — Australia, India, Japan, the Philippines, South Korea, and Taiwan — that are willing to push back against problematic Chinese behavior in different areas.

Second, shifting some additional resources to Asia does not require that the United States abandon its allies and partners in the rest of the world, particularly in Europe.²⁰ The trans-Atlantic relationship is a triumph of a century of U.S. foreign policy, and it should continue to be nurtured. European countries combined have an economy an order of magnitude larger than that of Russia, but rapid or unilateral changes would undermine regional security and embolden Russia. This can be avoided if NATO conducts a strategic reassessment of national roles, missions, and capabilities, informed by changes in American and European resourcing and capabilities. As Europe steps up, Washington should work with its NATO allies to jointly adjust allied force posture and capabilities on the continent. This would shift the allies’ focus from how much each country spends on defense to what they specifically bring to the table and how they can reinforce one another’s efforts.

Third, the United States should deprioritize, but not abandon, the Middle East. For nearly a century, the Middle East has been regarded as one of three priority theaters for American security, alongside Europe and Asia. This decision was driven in large part by the demand for oil to fuel the global economy and the American military, and later by concerns about terrorism. Yet, the American public’s concern about terrorism has ebbed, and the boom in U.S. energy production has altered the strategic importance of the Middle East.²¹ In fact, the U.S. military presence in the Middle East now protects energy supplies that flow in large part to China. The United States cannot be everywhere at once, so an adjustment in U.S. military force posture in the region is warranted. U.S. leaders should instead seek to keep a small residual force in the region in order to maintain cooperation with key partners and enable any future required deployments in the region.

Fourth, prior to the current Trump administration, U.S. engagement in Africa, Latin America, and South Asia was episodic at best.²² But the elimination of the U.S. Agency for International Development and the closure of many U.S. missions around the world have undercut U.S. engagement even further. It will be difficult, if not impossible, for any future U.S. administration to resurrect these institutions and relationships. Rather than struggling to do so across the board, leaders in Washington should prioritize a handful of strategic relationships in each region. The Director of the American Statecraft Program at the Carnegie Endowment for International Peace Chris Chivvis has thoughtfully examined the important roles of pivotal states like Brazil, India, and South Africa in their neighborhoods. U.S. policymakers should endeavor to deepen this cooperation strategically, while also continuing to encourage U.S. companies to remain active in seeking opportunities in places that might be overlooked by U.S. foreign policy.

Finally, the United States should pay more attention to the U.S. homeland, but this need not be a top mission for the U.S. military. Many Americans want border security to be a higher priority in order to address challenges pertaining to illegal immigration and drug trafficking. Leaders in Washington need to be responsive to these demands. Yet, U.S. policymakers should be clear that these are not U.S. military missions. The Department of Defense should remain focused on operating outside of U.S. borders, where its “lethality” mantra is more applicable.²³ Other agencies are better tailored to manage homeland security inside the United States and along its borders.

Conclusion

The United States took a leading role in reenvisioning the world order 80 years ago. Today, it should do so again. This time, the United States is not ascendant after victory in a world war, but rather on a slow path of relative decline after decades as the world’s unchallenged leader. A more fragmented world with many competing regional and global powers awaits. The emerging multipolar system will require U.S. leaders to think more about building flexible coalitions than fixed alliances, which will increase the complexity of the task ahead.

American policies today cannot resemble those of the 20th century for a second reason: The U.S. public is growing more skeptical of expending resources on international engagement. Memories of U.S. successes abroad are being replaced by frustration with a variety of failed endeavors overseas. Meanwhile, the U.S. debt is rising alongside calls for additional social spending, constraining expenditures on national security. Barring an inspirational leader or catastrophic conflict, these trends are unlikely to be reversed.

Multipolarity need not be a death sentence for America. If approached strategically, multipolarity could actually amplify some U.S. strengths and offset key weaknesses and vulnerabilities. This will require a series of tough discussions about resources and priorities, but that is unavoidable. The time is ripe, therefore, for the United States to proactively embrace multipolarity.

Notes

1
John F. Kennedy, “President John F. Kennedy’s Inaugural Address,” National Archives, January 20, 1961, https://www.archives.gov/milestone-documents/president-john-f-kennedys-inaugural-address.
2
U.S. Department of State, “Secretary Marco Rubio with Megyn Kelly of The Megyn Kelly Show,” interview, January 30, 2025, https://www.state.gov/secretary-marco-rubio-with-megyn-kelly-of-the-megyn-kelly-show/.
3
Zack Cooper, Tides of Fortune: The Rise and Decline of Great Militaries (New Haven: Yale University Press, 2025).
4
Jane Harman et al., “Commission on the National Defense Strategy,” RAND Corporation, July 2024, https://www.rand.org/nsrd/projects/NDS-commission.html.
5
Todd Harrison, “Affording Defense: How Much Is Too Much?,” (American Enterprise Institute, February 24, 2025), https://www.aei.org/articles/affording-defense-how-much-is-too-much/.
6
American political commentator Walter Lippmann said in 1943 that foreign policy “consists in bringing into balance, with a comfortable surplus of power in reserve, the nation’s commitments and the nation’s power.” When commitments exceed power, the resulting gap generates public discontent. See Walter Lippmann, U.S. Foreign Policy: Shield of the Republic (New York: Little Brown, 1943).
7
Samuel P. Huntington, “Coping With the Lippmann Gap,” Foreign Affairs 66, no. 3 (1988): 453–477, https://www.foreignaffairs.com/articles/1988-02-01/coping-lippmann-gap.
8
Steven R. Weisman, “Reagan to Request $38 Billion Increase in Military Outlays,” New York Times, March 4, 1981, https://www.nytimes.com/1981/03/04/us/reagan-to-request-38-billion-increase-in-military-outlays.html.
9
Zack Cooper, Connor Fiddler, Allison Schwartz, Emily Young Carr, and Ben Noon, Managing Multipolarity: Coalition Building in a Fragmented World (American Enterprise Institute, July 2024), https://www.aei.org/wp-content/uploads/2024/07/Managing-Multipolarity.pdf.
10
John Hawksworth and Danny Chan, The World in 2050: The Long View – How Will the Global Economic Order Change by 2050? (London: PwC, February 2017), https://www.pwc.com/gx/en/world-2050/assets/pwc-the-world-in-2050-full-report-feb-2017.pdf.
11
Nicholas Eberstadt, “The Age of Depopulation: Surviving a World Gone Gray,” Foreign Affairs, November/December 2024, https://www.foreignaffairs.com/world/age-depopulation-surviving-world-gone-gray-nicholas-eberstadt.
12
G. John Ikenberry, After Victory: Institutions, Strategic Restraint, and the Rebuilding of Order after Major Wars (Princeton, NJ: Princeton University Press, 2019).
13
Amitav Acharya, “Pharaohs, Maharajas, and the Making of a Multipolar World,” Foreign Policy, July 25, 2025, https://foreignpolicy.com/author/amitav-acharya/.
14
Richard Wike, Janell Fetterolf, Laura Clancy, and Jordan Lippert, “The United States’ Standing in the World,” (Pew Research Center, May 1, 2025), https://www.pewresearch.org/2025/05/01/the-united-states-standing-in-the-world/.
15
Gallup, “Steady 66% Want Leading or Major World Role for U.S.,” Gallup News, July 29, 2025, https://news.gallup.com/poll/657725/steady-leading-major-world-role.aspx.
16
https://www.pewresearch.org/global/2025/07/08/people-in-many-countries-consider-the-u-s-an-important-ally-others-see-it-as-a-top-threat/
17
Rebecca Lissner and Mira Rapp-Hooper, “Absent at the Creation? American Strategy and the Delusion of a Post-Trump Restoration,” Foreign Affairs, June 24, 2025, https://www.foreignaffairs.com/united-states/absent-creation-rebecca-lissner.
18
Jennifer Lind and Daryl G. Press, “Strategies of Prioritization: American Foreign Policy After Primacy,” Foreign Affairs, June 24, 2025, https://www.foreignaffairs.com/united-states/strategies-prioritization-lind-press.
19
Evan Braden Montgomery, In the Hegemon’s Shadow: Leading States and the Rise of Regional Powers (Ithaca, NY: Cornell University Press, 2016).
20
Zack Cooper and Luis Simón, “Rethinking Tradeoffs Between Europe and the Indo-Pacific,” War on the Rocks, May 9, 2023, https://warontherocks.com/2023/05/rethinking-tradeoffs-between-europe-and-the-indo-pacific/.
21
Michael Beckley, “The Power of Nations: Measuring What Matters, “International Security 43, no. 2 (Fall 2018): 7–44, https://www.jstor.org/stable/26333880.
22
Leslie Vinjamuri and Max Yoeli, “America’s Last Chance With the Global South,” Foreign Affairs, July/August 2025, https://www.foreignaffairs.com/united-states/americas-last-chance-global-south.
23
Melissa Dalton, “DoD’s Shifting Homeland Defense Mission Could Undermine the Military’s Lethality,” Center for Strategic and International Studies, April 22, 2025, https://www.csis.org/analysis/dods-shifting-homeland-defense-mission-could-undermine-militarys-lethality.