Issue Brief

Fit for Purpose? Assessing American Alliances

America’s network of alliances is often seen as one of its most valuable assets. But is it fit for purpose in a new era?

By Christopher Preble Author • Kelly A. Grieco Author • Emma Ashford Author • Hunter Slingbaum Research • Alessandro Perri Research • Marie-Louise Westermann Research • Will A. Smith Editor

Grand Strategy

April 29, 2026

Since World War II, America has relied on a global network of alliances to buttress and extend its own power, and these alliances have come to be viewed by many as a critical, even essential asset for the United States. Yet quantity is not quality; America’s alliances have expanded dramatically in the post-Cold War period, and many are now tethered to outdated strategic realities. The Assessing American Alliances project explores the question of whether America’s alliances are fit for purpose and scrutinizes the assumption that all alliances serve U.S. foreign policy goals. This paper presents the project’s central research findings, based on regional fieldwork and a comprehensive survey of U.S. allies. The evidence gathered suggests that Washington would be better served with a more flexible, issue-specific approach to alliances in today’s multipolar world.

Introduction

America’s global network of alliances and strategic partnerships has come to occupy a near-sacred place in U.S. foreign policy thinking. As the Biden administration’s 2022 National Security Strategy put it, America’s “alliances and partnerships around the world are our most important strategic asset and an indispensable element contributing to international peace and stability.”¹ Even the 2025 National Security Strategy — despite all of the Trump administration’s saber-rattling toward allies — argued that “America retains the world’s most enviable position, with world-leading assets, resources, and advantages, including… a broad network of alliances, with treaty allies and partners in the world’s most strategically important regions.”² This framing shapes the evaluation of U.S. foreign policy decisions, often reducing them to a single question: Does a given policy strengthen or weaken alliance commitments?

That consensus deserves scrutiny. By some counts, the United States has over 50 formal allies — around a quarter of the world’s nations — that it is obliged to defend against attack.³ And though most of these states are also nominally obligated to defend the United States, these commitments are asymmetric in practice. The United States also maintains relationships with quasi-allies such as Israel and Taiwan — security partnerships with ambiguous but highly entangled defense ties — without a formal commitment to defend.⁴ That some of these alliances have contributed to American national security is beyond doubt. But that does not mean that allied preferences necessarily overlap with American interests, that the current structure of the U.S. alliance system is fit for purpose, or that proposals to further build out a global network of alliances are the best choice for U.S. national security.

Managing that network is also harder than the consensus suggests. American resources are limited, and a commitment deepened in one region draws resources away from others. Additionally, there are differences in threat perception between allies: For instance, those in Eastern Europe may have a perception of global threats that is very different from that of American security partners in Latin America. Even countries that agree on threats may disagree on the remedy; smaller Southeast Asian states and more powerful Northeast Asian ones may both think China is a threat, but they will likely desire different policies in response. Allies themselves can have internally contradictory, complex, and shifting preferences dictated by domestic politics — preferences that may diverge sharply from American security interests and strategy.

In short: the future of U.S. alliances will depend on much more than simplistic binaries about “strengthening” or “weakening” U.S. alliances. In this paper, we kick off the Assessing American Alliances project by exploring perhaps the key assumption of U.S. alliance policy: that we know what allies think about their relationship with the United States. We explored what they want from Washington, what concerns them, and what they are willing to contribute, surveying foreign policy elites in 26 allied and partner countries, and conducting fieldwork across three regions. What we found presents a more nuanced picture than the standard Washington consensus on alliances. Allies undoubtedly see their relationships with the United States as important, but most think locally, not globally. They fear entrapment, as much as abandonment. And, most worryingly, the roles Washington may most need them to play are precisely the ones they are the least willing to take on.

Methodology & Survey Data

This project was built around two core research activities. The first is an online survey of foreign policy elites across 24 allied countries, as well as two quasi-allies — Israel and Taiwan — conducted in April 2025, with a second wave in July of that year. Most respondents were located in the Indo-Pacific and Europe, where most U.S. allies are based, while about 20% came from other regions, and they are also relatively evenly spread across major U.S. alliances (see the appendix for a full list of countries).

The target demographic for the survey was elite foreign policy analysts and observers, particularly those with either experience in or close interaction with the foreign policy making process. Most of our respondents are either academics or think tank/NGO employees, with a smaller subset of retired government officials; many respondents have multiple overlapping roles. We identified potential respondents using chain-referral sampling, relying on colleagues at the Stimson Center and within the broader think tank community who are regional specialists. These colleagues helped to act as referrers for respondents within their own analytical communities. The final sample is not fully representative — either of all U.S. allies or of all foreign policy elites within these states — but it is diverse enough to identify meaningful trends in how perceptions of the United States and its alliances are changing.

The survey itself included around 30 questions, including yes/no answers, multiple-choice answers, and several that encouraged free-form written responses. The short-form responses were particularly useful in assessing why participants might have answered prior questions as they did — when respondents suggested, for example, that U.S. economic coercion concerned them, we were able to cross-reference their written answers for more detail (see the appendix for the full survey questionnaire). Similar surveys or elite interviews often focus on the “health” of the alliance, or on what more the United States can do for its allies.⁵ We focus instead on a range of key topics drawn from the existing alliance literature: how allied elites feel about burden sharing, whether they hedge against abandonment by the United States, and how they feel about the risk of entrapment on both sides. The international relations literature offers a rich analytical foundation for these questions as many of the problems seen in today’s U.S. alliances are not new; they have been flagged in prior studies of alliance dynamics. The second research activity was field work in three regions where the United States has key alliances or partnerships — the Middle East, Europe, and East Asia. These visits included in-depth one-on-one interviews in Turkey, the United Arab Emirates, Taiwan, Japan, and the Philippines, along with more informal conversations and roundtable discussions in Germany, France, and South Korea. In these conversations with local foreign policy experts, we sought to understand their views of their home countries’ relationship with the United States. Where the survey identified broad patterns, the fieldwork helped to explain them, providing context, nuance, and illustrative examples that quantitative responses alone could not capture. Full data and methodology can be found on Stimson’s website.

Three findings emerged consistently across both research activities. First, though America views its alliance network in global terms, allies typically see threats to their own security locally rather than globally. Geography plays an essential and undervalued role in dictating allied threat perceptions and in shaping what they want from their alliances with the United States. Second, allies are deeply wary of being pressured to choose between China and the United States, and many fear entrapment in American conflicts as acutely as they fear abonnement. Finally, allied views on nuclear extended deterrence are more conflicted than the Washington consensus assumes—most allies want the protection of the U.S. nuclear umbrella but resist its own tangible manifestation, the deployment of U.S. nuclear weapons on their soil. Each finding is taken up in turn below.

Regional, Not Global Threats

Washington may view its alliance network in global terms, but allied elites do not. The divergence between how American policymakers talk about threats and how allies actually experience them is one of the most consistent findings of this project — and one of the most consequential for U.S. alliance policy.

For several administrations, Washington has sought to build coalitions around the global threats posed by China and Russia. The Biden administration, for example, pressed European allies to join export controls on advanced semiconductor technology bound for China — a demand that cut directly against the economic interests of states like the Netherlands. It also pushed states such as Japan and South Korea — energy-import dependent and separated from the conflict by thousands of miles — to participate in G7 statements and sanctions during the war in Ukraine.⁶ Both our survey and our regional discussions suggest that while allies typically go along with Washington’s impulses primarily to sustain U.S. support in their own region, their primary security concerns are closer to home. The survey data make this clear. China tops near-term threat concerns in the Indo-Pacific, cited by 71% of respondents, while Russia dominates threat perceptions in Europe at nearly 59%. Conversely, Russia barely registers in the Indo-Pacific at 3%, and China is a near-term threat for only 4% of Europeans. Other regions show similarly localized patterns: Middle Eastern respondents focus overwhelmingly on regional conflict and domestic polarization, while Latin American respondents identify domestic instability and the spillover effects of great power competition as their primary concerns.

These patterns also hold over the longer term. Climate change and regional instability have risen as key long-term concerns across all regions, but this overlap does not produce anything resembling a shared global threat picture. China gains only modest ground as a perceived threat in Europe; climate change and regional instability dominate the long-term threat picture in European responses.

Importantly, even when regions nominally share a threat, the nature of that threat differs. Europeans who view China as a long-term threat tend to emphasize economic dependence and coercive leverage, whereas Indo-Pacific respondents emphasize Chinese gray-zone activity (50%) or the prospect of China using military force against Taiwan (32%). In other words, naming the same adversary does not mean facing the exact same threat. Influential strands of American strategic thinking that envision “networked allied cooperation” or “allied scale” against a coordinated “axis of autocracy” among China, Russia, Iran, and North Korea tend to assume a shared threat calculus.⁷ If that were the case, one would expect allied threat perceptions to converge on a more uniform set of concerns — but they do not.

The same geographical logic shapes our allied military ambitions. When asked what level of native military capabilities they favor, 79% of respondents favor those capabilities suitable for independent territorial defense or in-region conflict (with or without U.S. participation). Only 5% favor out-of-area contributions to American operations. Across regions, respondents skew heavily toward enabling roles (i.e., nonlethal basing, logistical support, and political or economic measures), rather than preparation for direct combat. Indeed, only 19% anticipate participating in direct combat operations, and just 24% expect to provide basing access to the United States for conducting lethal strike operations elsewhere. In short, allies expect Washington to shoulder most of the combat burden.

Geography explains much of this variation. In land-dominated Europe, an invasion of one state immediately threatens its neighbors, and coalition formation becomes both necessary and natural. This is a dynamic NATO has institutionalized over decades.⁸Europeans are accordingly more likely to commit to collective defense, with 29% favoring direct participation in military operations and 28% favoring lethal basing access. Even so, the majority of Europeans still anticipate supporting rather than directly participating in combat operations. Likewise, 57% of respondents in Middle Eastern countries favor regional defense — consistent with a geography where Iranian proxies, terrorist networks, and regional armed groups routinely cross borders, making threats to one state immediately relevant to its neighbors.⁹ The maritime environment of the Indo-Pacific produces a different calculus. Respondents were split between capabilities suitable for an independent defense (47%) and those oriented toward a regional contingency, with or without U.S. support (30%). Yet this does not translate into a willingness to fight alongside the United States. The oceans function as a defensive barrier, reducing incentives for the kind of coalition-building that continental threats historically produce.¹⁰ Only 11% of Indo-Pacific respondents selected “regional military operations” as their country’s expected contribution in the event of a regional military contingency. Most respondents opted instead for logistical support, nonlethal basing access, or economic measures — forms of assistance that enable U.S. operations while keeping their own forces largely out of direct combat. As one Australian expert observed, this creates “expectations gaps around how and what Australia might contribute to a given contingency.”

Latin America is unique. Eighty-six percent of respondents prioritized independent defense, and none believed their countries should prepare to fight a regional contingency. At first glance, Latin America’s geography would seem to predict coalition formation — contiguous states, shared borders, and transnational threats that readily cross them. But coalitions coalesce around shared external dangers, and in the Western Hemisphere — where the United States is already the predominant power — there is no regional challenger against which to organize.¹¹ Absent external threat, American hegemony in the Americas discourages collective defense by removing the incentives that would otherwise drive it.

In this context, the preference for independent defense among our Latin American respondents likely reflects two related concerns: a desire to avoid being entrapped in America-led conflicts, and a desire to retain autonomous capabilities against Washington itself.¹² As one Brazilian respondent put it, “The American view that their security area extends to the entire Western hemisphere fails to properly consider Brazil’s interests and perspectives — this approach not only overlooks our strategic autonomy but also poses a potential threat to our own national security.” Washington, in short, is not just a security provider in Latin America, but also a risk to be managed.

These localized threat perceptions also shape what allies want from Wahington in terms of reassurance — the signals it sends to convince allies that its security commitments are credible — which mirror the pattern above.¹³ In the Indo-Pacific, respondents view U.S. naval deployments (82%) and bomber overflights (75%) as credible deterrents, as compared to 69% and 64% of Europeans, respectively. Given Chinese naval activity in contested waters and gray zone operations in the air and maritime domains, this is precisely what the geography of the threat environment would predict. By comparison, consistent with the logic of continental deterrence, Europeans value permanent U.S. bases (i.e., a forward ground presence) more than Asia-Pacific allies (69% as opposed to 59%). Middle Eastern respondents showed the highest support for a physical American basing presence of any region, with all respondents agreeing that both naval deployments and permanent U.S. bases improve their security. But what allies want and what serves American interests are not always the same thing — and the current U.S. war with Iran is also likely to highlight the risks that can come with hosting an American base.

Latin America again tells a different story. Latin American respondents were actively skeptical that American security commitments improve their security at all, rating every American reassurance measure — with the sole exception of joint military exercises — as leaving their country less secure rather than more. The practical implication is the same regardless of whether this skepticism reflects a long history of American interventionism in the region, the realities of physical proximity to the United States, or simply the challenges of living under the shadow of American power: American reassurance measures may be actively counterproductive in the region. This finding, moreover, predates the recent American operation in Venezuela — an event unlikely to have moved Latin American opinion in Washington’s favor.¹⁴

Taken together, these findings reveal that allied security thinking is stubbornly localized and shaped by specific regional geographies. Washington may aspire to have allies who think and act globally, but allies consistently prioritize their own territory and their neighborhoods. That shapes their threat perceptions, their military ambitions, and their expectations of what the United States should — and should not — do on their behalf.

Fears of Great Power Competition

For many U.S. allies, the greatest long-term threat is not China or Russia — it is being forced to choose between them and the United States. About one-fifth of respondents in the Indo-Pacific and one-quarter of respondents in Latin America view great power competition itself as the biggest long-term threat to their state’s interests — independent of any direct threat from China, Russia, or the United States. Many allies perceive the roles played by the United States and China as intrinsically different and ideally complementary: The United States is important for global security provision, while China is an essential economic partner. The perception that Washington is asking countries to choose between the two creates a problem that allies across regions consistently identified. Almost two-thirds of respondents agreed that their alliances with the United States make it more difficult to engage economically with China. Similar numbers said it complicates diplomacy with U.S. adversaries more broadly. One Thai respondent identified the core problem as a potential “U.S. policy of forcing us to choose between U.S. or China during peacetime.” Another explained why, suggesting, “Thailand would still support efforts to maintain a balanced and rules-based order, but it has no interest to do anything to confront China directly.” Part of what makes this tension so difficult to manage, as one former senior Philippine official noted, is that China cultivates local ties and investments relationships, giving it leverage Washington cannot easily counter. As another Philippine expert observed, the “majority of economic elites in the Philippines are very pro-China and drooling over the idea of getting more government-to-government projects.”

This preference for hedging is not confined to Southeast Asia. A Colombian respondent described his country’s approach as “strategic pragmatism: preserving its essential security alliance with the United States, carefully engaging China where it serves economic development.” That strategic pragmatism included “building institutional resilience to avoid becoming a pawn in great power competition.” A Brazilian expert similarly stated that “Brazil cannot and should not be forced to choose between the United States and China.” In the Middle East, Turkish experts emphasized that decades of forced hedging between the United States, Europe, and Russia had given Ankara substantial freedom of maneuver — and they intend to continue this course. One Turkish academic proposed that “Ankara should act as a bridge-builder, exporting defense tech like drones to NATO, engaging in Chinese-led infrastructure projects, and deepening energy links with Europe — reducing vulnerability to any one side’s pressure.” Emirati interlocutors expressed a similar logic, describing a strategy of leveraging “connections with China and Chinese firms to attract investments, technology partnerships, and more trade, while also relying on the United States for deterrence, maritime security, and some higher-end technologies.” Across regions, the pattern is consistent: Allies want the benefits of the U.S. security partnership without being drawn into Washington’s conformational posture toward China.

The great power competition paradigm creates a second problem beyond the pressure to choose: entrapment risk. This concern is most acute in the Indo-Pacific, where the potential for future conflict is highest but active conflict is currently absent. In Europe, where the military threat from Russia has been clearer since at least 2022 — and where the United States has even been a restraining voice on some Eastern European states — respondents worry far less about the potential entrapment risk created by U.S. forces in the region. Almost 80% of respondents who saw Russia as a primary threat in Europe believed that a U.S. base would make their country somewhat or significantly more secure, and only 10% believed it would make them less secure. The same pattern holds in the Middle East, where threats from Iran are relatively clear, and where almost 80% believed that a U.S. base might make them more secure (though one suspects that those numbers might look different after the current war).

Indo-Pacific allies present a different picture. They hold classic bimodal concerns: On the one hand, they fear American abandonment, but on the other, they worry about “entrapment” risks in which the United States pulls them into unwanted conflict. Among those who identified China’s military as their primary concern, respondents believed that U.S. bases would make them more secure by an almost two-to-one ratio. Among those with other concerns, that ratio flipped, with two-thirds of respondents believing it would make them less secure.

Taiwan sits at the center of this tension. Many respondents identified disagreements over their “expected role in a Taiwan contingency” as the event most likely to damage their relationship with the United States. One Australian expert, for example, highlighted that Washington and Canberra disagree on “the salience of the China military threat — and particularly the Taiwan question — as the absolute organizing principle for regional strategy.” Conversations with current and former Japanese and Philippine defense officials further highlighted the gap between Washington’s expectations and what allies are prepared to do in a Taiwan contingency. In Tokyo, officials emphasized legal and domestic political constraints on Japan’s use of force and cautioned against expecting Tokyo to assume a direct combat role in the event of a Tawan conflict. In Manila, officials were even more cautious, indicating that U.S. access to Philippine bases in a Taiwan contingency was far from assured.

Yet while many U.S. allies in the Indo-Pacific appear strongly disinclined to join the United States in a direct fight over Taiwan and desire American military restraint, they also express strong reservations about the possibility of U.S. abandonment. A Taiwanese respondent noted “a sense of uncertainty that the U.S. could reach a grand bargain with China, with Taiwan being the expense.” A Japanese respondent similarly worried about a “U.S. unilateral deal with China.” An expert from the Philippines raised concerns about America’s “business approach to China.” This expert further explained: “It [the U.S.] may decide to pursue policy thrusts that may benefit it, but [would] be inimical to its allies/partners.” The result is a set of alliances caught between two fears: that the United States will drag them into a war that they do not want, or that it will cut a deal that leaves them exposed.

In this respect, Indo-Pacific alliances may be healthier than their European counterparts. As our field interviews suggested, foreign policy elites in Europe are primarily preoccupied by fears of U.S. abandonment — and increasingly by the prospect that NATO might not survive another Trump term intact. But where NATO has become institutionalized and rigid, Asian alliances are more flexible and less institutionalized, leading allies to worry both about abandonment and entrapment. That dual concern creates stronger incentives for burden sharing: Indo-Pacific allies are willing to engage in burden sharing precisely because they cannot take the U.S. commitment for granted, and because they want to give Washington enough reason to stay engaged without pulling them into conflicts with China.

Allies and Nuclear Weapons

For almost as long as the United States has been in possession of nuclear weapons, American strategists have imagined how these weapons could be used for deterrence, including deterring attacks on allies. This so-called “extended deterrence” is often seen as critical to discouraging other countries from wanting their own nuclear weapons. Indeed, it is widely believed that U.S. nuclear weapons — and the threat to use them to deter not only attacks on the United States, but also attacks against allies and their territory — have discouraged nuclear proliferation among U.S. ¹⁵

U.S. policy is routinely oriented around making these extended deterrent threats credible. The most common of these theories is the notion of a “tripwire,” in which the deployment of a small number of American troops increases the likelihood of a U.S. response — and a larger response than would otherwise be warranted to defend core U.S. national interests.¹⁶ Other scholars of U.S. nuclear weapons policy explain U.S. nuclear posture and doctrine on the grounds of extended deterrence. Starting in the 1960s, the United States rejected the vulnerability implied by “mutually assured destruction,” aiming instead for a credible first-strike capability to limit damage within the United States. This, in turn, was expected to convince U.S. allies that the United States was serious about taking risks for their security and would not need to “trade Boston for Berlin” to do so.¹⁷ Collectively, these measures fall under the rubric of alliance assurance.

Our research found that allies broadly want the U.S. nuclear umbrella while opposing the deployment of those nuclear weapons on their soil. Views on the need for U.S. troops to act as tripwires vary, but support for the proposition that U.S. troop deployments are vital for deterrence is modest, at best. That opposition matters because credibility is the central problem of extended deterrence.

Desire for an American extended deterrent correlates strongly with fears about China or Russia. Nearly nine in 10 (88%) who prioritized China as a threat, and over three-quarters (78%) who prioritized Russia, wanted the United States to extend its nuclear umbrella to their nation. By contrast, the U.S. extended nuclear umbrella was less popular among those respondents who prioritized other threats to their security, but still commanded majority support. For example, 54% who prioritized domestic political polarization as their most urgent security concern still favored being under the U.S. nuclear umbrella.

There is no consensus, however, on what it takes to establish the credibility of U.S. extended deterrence. Only 13% of respondents said that U.S. troop deployments in their country would make them “significantly more secure”; another 40% responded that a U.S. troop presence would make them somewhat more secure. Nearly every other option on offer fared better: Survey participants said that joint exercises (44%), naval patrols (31%), regular bomber patrols (28%), and U.S. stockpiles (27%) would all make them “significantly more secure” against “the threat of military aggression.” The conventional wisdom holds that conventional force “tripwires” are needed to make extended deterrence credible; our survey did not find support for that Washington consensus.

Meanwhile, a majority among nearly every group of respondents believed that their security would be undermined by the presence of U.S. nuclear weapons in their country. Less than half of individuals most concerned about China (48%) believed that hosting U.S. nuclear weapons would enhance their security. Among those who were most concerned about great power competition, barely one in four (26%) wanted U.S. nuclear weapons deployed within their territory. Ally-level sample sizes are too small to draw strong inferences, but respondents in Denmark, the Philippines, and Turkey were most skeptical of having U.S. nuclear weapons deployed in their countries, while those from Italy, Poland, South Korea, and Taiwan were most supportive. A Philippine diplomat emphasized that Article II, Section 9 of the 1987 Philippine constitution prohibits nuclear weapons on its territory. A senior defense official in Japan stressed the need for great consultation with the United States on nuclear weapons but did not signal a desire for an indigenous Japanese nuclear deterrent.

Doubts about U.S. leaders’ commitment to extended deterrence could undermine non-proliferation efforts. If the U.S. nuclear umbrella is sufficiently reassuring, allies should have little reason to pursue their own arsenals. On the other hand, it is reasonable to speculate whether U.S. leaders’ rhetoric vis-à-vis allies — including President Trump’s threat to let the Russians “do whatever the hell they want” to any NATO country that doesn’t pay up — may cause people previously opposed to acquiring a nuclear arsenal to reconsider.

Our findings complicate that logic. Support for developing an indigenous nuclear deterrent varied sharply by region, even after existing nuclear weapons states (France, Israel, the United Kingdom) are excluded from the sample. A clear majority of respondents in the Middle East (60%) wanted their own nuclear arsenal, but fewer than four in 10 (36%) in Europe and a mere 17% in the Indo-Pacific wished for their country to join the ranks of nuclear weapons states.

These findings are more nuanced when one drills down farther. None of the respondents in 14 of the 23 states that did not already possess nuclear weapons — in other words, excluding France, Israel, Pakistan, and the United Kingdom — agreed that their defense should include an indigenous nuclear arsenal. In the other nine states where there was some support for acquiring nuclear weapons, including among respondents from Japan, Poland, South Korea, Turkey, and Taiwan, it remained a minority view. And a South Korean expert urged caution in interpreting poll results regarding support for nuclear weapons: “The polling doesn’t ask follow-up questions,” the expert noted, including “asking South Koreans if they are willing to pay the costs.” Notwithstanding reasonable doubts, therefore, about the United States’ commitment to extended deterrence, most allies are not looking to replace the U.S. nuclear umbrella with one of their own.

Conclusion

Policymakers and scholars should continue to critically examine the role that alliances and security partnerships play in U.S. foreign policy. Some U.S. priorities overlap with the priorities of our allies and partners; many do not. By pursuing alliances for the sake of adding friends to our inventory, the United States puts itself in a position to take on more responsibilities that have little to do with its interests abroad and expend Americans’ limited resources on issues we would not otherwise prioritize. One big assumption about U.S. alliances is clearly flawed: Contrary to the Washington consensus, American alliances are not useless, nor an unqualified strategic asset, nor are they monolithic. This project paints a more complicated picture: allies that want American security guarantees, but worry about certain kinds of American military presence; partners who think locally, even as Washington asks them to think globally; and states that fear entrapment by the United States as acutely as they fear abandonment by it.

Indeed, the long-running Washington assumption that alliances and security partnerships are an unalloyed good often conflicts with much of the academic research on the potential risks and rewards of alliances. In particular, policymakers should stress test the notion that American policymakers should continue to pursue a bloc-based strategy — one that was formed by the experience of the Cold War with the Soviet Union — as a core component of U.S. grand strategy.¹⁸ Kurt Campbell, the Biden administration’s Indo-Pacific czar, for example, has argued that bilateral relationships alone will not suffice and that U.S. alliances in Asia must be gathered into a broader collective defense pact.¹⁹ He has also, alongside Biden China hand Rush Doshi, suggested that allies and their defense industrial resources should be leveraged to sustain U.S. global hegemony. They argue that Washington “must transform its alliance architecture … to a platform for integrated and pooled capacity building across the military, economic, and technological domains,” a truly unprecedented level of alliance commitment that would turn American alliances into one coordinated industrial bloc.²⁰ Yet our research suggests a “one size fits all” strategy is not appropriate given the variety of views, security needs, and diverse geographical considerations faced by U.S. allies.

Nor does unrestrained pressure on allies necessarily produce good results. The primary period during which this project was conducted lined up with the first year of the Trump administration, and a period of sudden, unexpected exercise of U.S. power against both allies and adversaries alike, from trade policy to military pressure. Both the trepidation of allies about “great power competition” and direct fears of the United States — though not an overwhelming part of our survey sample — are likely a reflection of the Trump administration’s coercive approach to alliances around the world. Over time, this will lead U.S. allies and partners to hedge, and to move away from the United States. It is not a good strategy either.

Other options than these two extremes exist. Generations of Americans viewed alliances with trepidation. In his famous farewell address, George Washington advised the new nation to “steer clear of permanent alliances.”²¹ This approach was also widespread among European countries for centuries and is still practiced by states like India and Vietnam today. It is possible that U.S. foreign policy could benefit from a downsizing or recalibration of existing alliances, the creation of a more equal set of defense partnerships, or even a return to a more temporary, conditions-based approach to coalition building. Perhaps the United States needs — as Undersecretary of Defense Elbridge Colby put it this year to attendees at the Munich Security Conference — “partnerships, not dependencies.” Returning to a view of alliances as flexible, temporary security arrangements would also better serve U.S. interests today. As the world enters an era of multipolarity, Washington’s rigid approach to alliances is in danger of becoming outdated.²² By looking for more issue-specific partnerships, minilateral groupings, and regional organizations that offer greater strategic flexibility — particularly those that do not automatically assume U.S. security guarantees — American policymakers will be in a better position to adapt to an evolving international system where threats and security interests frequently change.

Appendix Table 1

Appendix Table 2

Notes

1
Government of the United States of America, The White
House, “National Security Strategy,” (Washington, DC: The White House, 2022), 11, https://bidenwhitehouse.archives.gov/wp-content/uploads/2022/10/Biden-Harris-Administrations-National-Security-Strategy-10.2022.pdf.
2
Government of the United States of America, The White House, “National Security Strategy,” (Washington, DC: The White House, 2025), 6, https://www.whitehouse.gov/wp-content/uploads/2025/12/2025-National-Security-Strategy.pdf.
3
Natalie Armbruster and Benjamin Friedman, “Who Is an Ally, and Why Does It Matter?,” Defense Priorities, June 18, 2024, https://www.defensepriorities.org/explainers/who-is-an-ally-and-why-does-it-matter/.
4
Zuri Linetsky, “The Difference between an Ally and a Partner,” Institute for Global Affairs, February 15, 2023, https://instituteforglobalaffairs.org/2023/02/the-difference-between-an-ally-and-a-partner/.
5
Jana Puglierin et al., “Transatlantic Twilight: European Public Opinion and the Long Shadow of Trump,” European Council on Foreign Relations,
February 12, 2025, https://ecfr.eu/publication/transatlantic-twilight-european-public-opinion-and-the-long-shadow-of-trump/.
6
Oskar Pietrewicz, “Japan’s and South Korea’s Response to the Russian Invasion of Ukraine,” The Polish Institute of International Affairs, March 3, 2022, https://pism.pl/publications/japans-and-south-koreas-response-to-the-russian-invasion-of-ukraine.
7
See, for example, Andrea Kendall-Taylor and Nicholas Lokker, The Axis of Upheaval: Gauging the Growing Military Cooperation Among Russia, China, Iran and North Korea (Washington, DC: Center for New American Security, July 2025), https://www.cnas.org/publications/reports/the-axis-of-upheaval; Hal Brands, “The New Autocratic Alliances,” Foreign Affairs, March 29, 2024, https://www.foreignaffairs.com/united-states/new-autocratic-alliances.
8
Kelly A. Grieco and Jennifer Kavanagh, “The Elusive Indo-Pacific Coalition: Why Geography Matters,” Washington Quarterly 47, no. 1 (2024): 103-121, 106-107.
9
See, for example, Kali Robinson and Will Merrow, “Iran’s Regional Armed Network,” Council on Foreign Relations, April 15, 2024, https://www.cfr.org/articles/irans-regional-armed-network.
10
Grieco and Kavanagh, “The Elusive Indo-Pacific Coalition,” 106-107.
11
Stephen M. Walt, The Origins of Alliances (Ithaca, NY: Cornell University Press, 1987).
12
Glenn H. Snyder, Alliance Politics (Ithaca, NY: Cornell University Press, 1997); See Lee Schoultz, Beneath the United States: A History of U.S. Policy toward Latin America (Cambridge, MA: Harvard University Press, 1998).
13
Jeffrey W. Knopf, “Varieties of Assurance,” Journal of Strategic Studies 35, no. 3 (June 2012): 375-399.
14
Chase Harrison and Khalea Robertson, “Reactions to the U.S. Operation in Venezuela, from Latin America and Beyond,” Americas Society/Council of the Americas, January 5, 2026, https://www.as-coa.org/articles/reactions-us-operation-venezuela-latin-america-and-beyond.
15
Francis J. Gavin, “Strategies of Inhibition: U.S. Grand Strategy, the Nuclear Revolution, and Nonproliferation,” International Security 40, no. 1 (2015): 10-11.
16
For a critical assessment of tripwires and whether they do or do not deter, see Dan Reiter and Paul Poast, “The Truth About Tripwires: Why Small Force Deployments Do Not Deter Aggression,” Texas National Security Review 4, no. 3 (2021): 33-53, http://dx.doi.org/10.26153/tsw/13989.
17
See, for example, Austin Long and Brendan Rittenhouse Green, “Stalking the Secure Second Strike: Intelligence, Counterforce and Nuclear Strategy,” Journal of Strategic Studies 38, no. 1-2 (2015), https://doi.org/10.1080/01402390.2014.958150; Francis J. Gavin, “Rethinking the Bomb: Nuclear Weapons and American Grand Strategy,” Texas National Security Review 2, no. 1 (January 2019): 74-100,
http://dx.doi.org/10.26153/tsw/867.
18
Emma Ashford, First Among Equals: U.S. Foreign Policy in a Multipolar World (New Haven: Yale University Press, 2025), 130.
19
Ely Ratner, “The Case for a Pacific Defense Pact,” Foreign Affairs, May 27, 2025, https://www.foreignaffairs.com/china/case-pacific-defense-pact-ely-ratner.
20
Kurt M. Campbell and Rush Doshi, “Underestimating China,” Foreign Affairs, April 10, 2025, https://www.foreignaffairs.com/china/underestimating-china.
21
Government of the United States of America, U.S. Congress, “Washington’s Farewell Address to the People of the United States,” 106th Cong., 2d sess., S. Doc. 106-21, (Washington, DC: U.S. Congress, 2000) https://www.senate.gov/artandhistory/history/resources/pdf/Washingtons_Farewell_Address.pdf.
22
Emma Ashford, First Among Equals, 8.

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