The Competitive Advantages and Risks of Alliances

Topical Essays

The Competitive Advantages and Risks of Alliances

Oct 30, 2019 31 min read

The Competitive Advantages and Risks of Alliances
A Royal Thai and a U.S. soldier pull security during counter-IED training Jan. 30, 2019, at Camp Nimman Kolayut, Thailand. U.S. Army photo by Staff Sgt. Samuel Northrup

Kathleen J. McInnis, PhD1

Winston Churchill once famously quipped, “There is only one thing worse than fighting with allies, and that is fighting without them.” So it goes for the complex web of security relationships that the United States maintains with states around the globe. Alliances and partnerships between sovereign states are often exasperatingly difficult to manage; domestic politics, burden sharing, and diverging strategic considerations create friction points that threaten to collapse them altogether.2

Despite the enormous amount of time and attention that U.S. leaders devote to maintaining alliances, allies and partners often make policy choices that are at odds with U.S. foreign and national security priorities. Further, the Founders admonished us to beware of “entangling alliances” that could embroil the United States in conflicts and conflagrations that were not necessarily in our interest.3 It is hardly surprising, therefore, that successive Administrations going back at least to 1949 have grumbled about equitable sharing of the security burden and have approached the topic of alliances overall with a note of ambivalence.

Yet since the end of World War II, successive Administrations have also determined that, despite these philosophical reservations and everyday frustrations, the contemporary system of U.S. alliances and cooperative security partnerships has conferred a number of strategic advantages that make the hassle worth its attendant risks. This “hub-and-spoke” alliance system is unique in human history; it has evolved into an unprecedented set of institutions and collaborative patterns that undergird a higher degree of global stability among sovereign states than history might otherwise have predicted.4

Militarily, the system allows the United States to advance its interests, perform expeditionary operations, and “defend in depth” at considerably lower cost than would otherwise be possible. Economically, it has allowed the United States to set the rules of international trade and finance and, on balance, remain well positioned to reap the advantages of that system. In aggregate, the system of alliances and security partnerships that the United States currently leads has afforded enormous strategic advantages to both the U.S. and those states that participate in it.

Evolution of the U.S.-Led International Security System

To understand alliances today, we need first to understand how we got here. Thucydides tells us that alliances have been an enduring feature of war and conflict for thousands of years.5 Multilateral military arrangements allow states (and their historical analogues) to aggregate their capabilities and collaborate on common security challenges.

Since the signing of the Treaty of Tordesillas between Spain and Portugal in 1494—an event that some strategic scholars point to as the beginning of the modern global system6—alliances have been formed between nation-states and their proxies in order to wage war against common adversaries. Alliances at that time were essentially agreements by European empires to combine military and economic assets in pursuit of political objectives. The European continent was the stage for many of these conflicts between states. However, colonies provided both critical resources as well as logistical bases for European capitals, and as global empires gradually expanded and grew in strategic importance, European territories around the world were drawn into supporting these alliances and were themselves made the subject of imperial competition.

The world wars during the first half of the 20th century brought the imperial system of global order crashing down. The European colonial powers no longer had the wherewithal either to maintain their global possessions or to lead the international system. As the United States became the dominant global power in the wake of those wars, it shaped the global system in a manner more consistent with its own anti-imperial values.7 It did this by building its security and strategic relationships in two primary ways: through formal strategic-political institutions such as the United Nations and the North Atlantic Treaty Organization (NATO) and by working with newly sovereign states rather than by taking over the possession of colonial territories.

In the aftermath of World War II and as the Cold War with the Union of Soviet Socialist Republics (USSR) took shape, the U.S. and its security partners decided to integrate economic instruments into their security calculations.8 As the theory went, doing so would make states more resilient against the specter of Communism and Soviet expansionism. Hence, European reconstruction was accompanied by the Marshall Plan and NATO. NATO itself was designed with the economic and social policy compatibility of its member states in mind.

Globally, the Bretton-Woods system, including the World Bank Group and the International Monetary Fund (IMF), would help to reconstruct European economies, facilitate trade among free-market economies, and, when possible, help newly independent states transform themselves from colonial territories to full-fledged participants in the international economy.9 Security relationships with the United States, including the U.S. extended nuclear deterrence umbrella, helped to make allies in Europe and Asia capable of withstanding Soviet influence operations.10

The design of an international system that benefited a wide variety of stakeholders was not an entirely altruistic calculation by U.S. post–World War II leaders. The war and the nuclear age that followed it underscored the fact that the continental United States was no longer protected by the Atlantic and Pacific Oceans.

Looking to the experience of Europe and Asia during the war and anxious to avoid a conflict that would comparably damage the American homeland, defense planners pursued a strategy of “defense in depth.”11 By positioning U.S. forces and capabilities forward in territories closer to adversaries, conflicts could be fought and won without directly affecting the continental United States. Basing agreements and alliance commitments, enabled in part by friendly economic relations and a common desire to contain the spread of Communism, were reached between the United States and a variety of countries in order to implement this defense-in-depth strategy. By the end of the Cold War, the United States had constructed a network of security relationships with sovereign states that was generally supportive of U.S. leadership of that system.

The end of the Cold War and the collapse of the Soviet threat around which the U.S. security system was organized led to a degree of soul-searching among scholars and policymakers: Why maintain these alliances and security relationships absent the threat they were designed to counter?12 These concerns proved short-lived, however, as allies and partners began to organize their security relationships and priorities around the collective management of regional crises and threats, particularly in the Middle East, Africa, and Southeastern Europe.

The United States used its existing alliance and security partnerships to adopt an expeditionary defense posture, retaining some key sites abroad that were critical for force projection (such as Ramstein Air Force Base in Germany) while closing bases and infrastructure that were no longer deemed necessary. (Such overseas bases have also been critical to managing regional “rogue” states such as Iraq, North Korea, and Iran—the latter two primarily through deterrence and forward-stationed troops and the former through active containment measures such as no-fly zones.)

The terrorist attacks of September 11, 2001, brought home the fact that there were key threats to the U.S. homeland that were not state-based: Ungoverned spaces provided the terrain for violent extremist groups to organize and metastasize into threats with a global reach. As the United States, in response, began to wage campaigns in Afghanistan, Iraq, and eventually Syria, the Department of Defense (DOD) subsequently expanded its programs to “build partner capacity” by working with fragile states in order to help them expand their capacity to govern and also, critically, their ability to eliminate threats posed by violent extremist organizations within their territory. As then-Secretary of Defense Robert Gates noted:

Building the governance and security capacity of other countries was a critical element of our strategy in the Cold War…. But it is even more urgent in a global security environment where, unlike the Cold War, the most likely and lethal threats—an American city poisoned or reduced to rubble—will likely emanate from fractured or failing states, rather than aggressor states.13

The American expeditionary military posture, including key staging and logistical sites, has remained critical to enabling U.S. counterterrorism and capacity-building operations in theaters around the world. The security networks that the United States constructed as part of this strategic shift have also helped the U.S. to achieve other transnational security objectives, including nuclear counterproliferation.

The Russian annexation of Ukraine’s Crimean Peninsula in 2014, along with near-simultaneous island building by China in the South China Sea, led U.S. policymakers to conclude that these powers are willing to use military tools to advance their strategic objectives and, in the process, damage the interests of the United States and its allies and partners. This emerging “strategic competition” with other powers has added to the scope and scale of the challenges with which the U.S.-led security order—already busy managing North Korea and Iran and countering violent extremists—must grapple. As the 2017 National Security Strategy notes:

China and Russia challenge American power, influence, and interests, attempting to erode American security and prosperity. They are determined to make economies less free and less fair, to grow their militaries, and to control information and data to repress their societies and expand their influence. At the same time, the dictatorships of the Democratic People’s Republic of Korea and the Islamic Republic of Iran are determined to destabilize regions, threaten Americans and our allies, and brutalize their own people. Transnational threat groups, from jihadist terrorists to transnational criminal organizations, are actively trying to harm Americans. While these challenges differ in nature and magnitude, they are fundamentally contests between those who value human dignity and freedom and those who oppress individuals and enforce uniformity.14

This has led to a hybrid of the defense in depth and expeditionary military postures. The European Deterrence Initiative (EDI), for example, is a U.S.-led effort to:

  1. Continue to enhance our deterrent and defense posture throughout the theater by positioning the right capabilities in key locations in order to respond to adversarial threats in a timely manner.
  2. Assure our NATO allies and partners of the United States’ commitment to Article 5 and the territorial integrity of all NATO nations.
  3. Increase the capability and readiness of U.S. Forces, NATO allies, and regional partners, allowing for a faster response in the event of any aggression by an adversary against the sovereign territory of NATO nations.15

Simultaneously, the U.S. has conducted counterterrorism and capacity-building operations in Afghanistan, in Iraq, and to some extent in Syria, using logistical infrastructure in Europe and the Middle East. None of this would be possible were it not for robust U.S. strategic and security relationships with allies around the world.

In summary, since the end of World War II, the United States—in contrast to the global powers that preceded America’s rise—has worked to establish an international security system of sovereign states and international institutions rooted in relatively advantageous economic relationships. After the end of the Cold War, that system adapted to perform crisis management tasks. In the wake of the September 11 attacks, the system broadened still further as the United States partnered with fragile, weak, and failing states to improve the capacity of their security institutions to manage threats emanating from their territories before they could become global threats. In this network of formal and informal security relationships, the U.S. serves as the central foundation (the hub) for a global defense and military architecture (the spokes) that manages regional and international security challenges.16

Defining Alliances

Given the centrality of alliances to United States defense and security planning, as well as to grand strategy in general, it is somewhat surprising that contemporary examples of alliances remain rather poorly understood. Part of the confusion stems from the variety of ways in which scholars define the term “alliances.”17 Insofar as there is consensus, it is generally held that alliances are some sort of agreements between states to render military support against an external threat under predetermined conditions.18 It is also generally understood that states make alliances in order to aggregate their military capabilities relative to external threats.

All of this makes sense to some degree: The overwhelming bulk of analyses of alliance structures, processes, formation, and so on have been derived primarily from cases involving Western European states, their empires,19 or both and often focus on historical periods up to the end of the Cold War, with comparatively little attention paid to alliances in the period following the Cold War.20

Thus, confusion surrounding the definition of “alliances,” coupled with a lack of analysis of military alliances in the post–Cold War era, has limited our understanding of contemporary multilateral military alignments, contributing to an overall confusion about the utility and risks of the U.S.-led global security system. For example, up until the end of World War II, the terms “alliance” and “coalition” were interchangeable, as both referred to acts by states to prosecute military operations jointly against a common threat.21

Parsing out coalitions from alliances has not always been a terribly important distinction to make: Alliances were often formed with the specific intention of prosecuting immediate or prospective coalition warfare or to prepare for the eventuality that warfare might occur. Furthermore, alliances, particularly during the Cold War, had a sense of unanimity to them; it was unthinkable that not all NATO allies might respond to an incursion by the Warsaw Pact, vagaries in Article V notwithstanding.

This is not generally the case today. Contemporary international organizations and alliances are often formed without the specific goal of collaboratively conducting military operations, and when international organizations or other institutions do decide to undertake multilateral military operations, they often do so utilizing a subset of their membership. Not all NATO members have participated in all of NATO’s post–Cold War operations.

Today, this U.S.-led hub-and-spoke system includes a variety of different strategic arrangements, most of which do not fit commonly accepted definitions of alliances. These arrangements include:

  • International institutions, such as the United Nations Security Council and the Organization for Security and Cooperation in Europe (OSCE), to contend with security challenges;
  • Multilateral military organizations like the North Atlantic Treaty Organization (NATO) alliance itself;
  • Explicit agreements between states, such as the mutual defense pact between the United States and the Republic of Korea, to provide mutual military support in times of crisis;
  • Participation by states, such as those that contributed to the International Security Assistance Force in Afghanistan, in military coalitions;
  • Strategic alignments between states, such as the U.S. relationship with Israel, that are not underpinned by a treaty arrangement; and
  • Bilateral, informal partnerships with other states.

It is difficult to determine the utility of these multilateral alignments without an appreciation of their various forms and how they contribute overall to U.S. and global security. In the first instance, motivations for different states’ participation in this system vary, which is why these relationships range from highly formalized treaty-established agreements on the one end to informal security cooperative arrangements on the other. Some are designed to assist states as they grapple with internal security challenges. Others are focused on deterring and, if necessary, defeating an external threat.

Some states with adversarial relationships join multilateral security institutions at least in part in order to tether (and be tethered to) their adversaries, thereby (counterintuitively) advancing their own national security interests. The involvement of Greece and Turkey in NATO is one such example.22 Some states choose to participate in multinational military coalitions in order to advance interests that have little to do with the mission or operation in question.23 A variety of states participating in the NATO-led International Security Assistance Force in Afghanistan, for example, did so in order to affirm their solidarity with other NATO countries or their bilateral relationships with the United States.24

From a policymaking standpoint, understanding this wide variety of motivations is critical. Without an appreciation for why and how states join these arrangements in the first place, it is difficult to make policy judgements about the level of risk they might be willing to shoulder in the event of multilateral military operations or other activities—or, indeed, for what type of security challenges they would consider employing military force at all.

Our standard conception of alliances and their de facto focus on military aspects of statecraft are becoming dangerously outdated, in part because they are rooted in realpolitik-inspired notions of military strength and capability aggregation. While these are, of course, essential aspects of alliances, they by no means capture the sum total of the role alliances play in contemporary international relations and strategic policymaking. As noted, more often than not, formal alliances are undergirded by close economic and political ties that serve as a key way to ensure the continued harmonization of the signatory parties’ overall political and strategic views. The more formal the alliance arrangement is, the more likely it is to be complemented by a trade agreement or close economic ties, many of which arguably benefit the United States.25 While most NATO-watchers are well versed in that alliance’s Article 4 (crisis planning) or Article 5 (collective defense) Treaty of Washington provisions, Article 2 has been all but forgotten:

The Parties will contribute toward the further development of peaceful and friendly international relations by strengthening their free institutions, by bringing about a better understanding of the principles upon which these institutions are founded, and by promoting conditions of stability and well-being. They will seek to eliminate conflict in their international economic policies and will encourage economic collaboration between any or all of them.26

This logic—that economic interdependence must underpin security institutions for them to be successful in the long term—is arguably why the U.S. sought the development of trade relationships among postwar democracies.27 It is also why global economic institutions such as the World Bank and IMF were established alongside the United Nations Security Council.28 Less formal security arrangements are generally accompanied by sales of U.S. defense equipment and other matériel to partner countries; in fact, foreign military sales were at one time a gauge by which U.S. versus Soviet global influence was measured.29

This aspect of international relations does not always function perfectly (hence the trade wars with Japan in the late 20th century), but on balance, it has served to create an interdependent group of states, led by the United States, that resolve issues among each other in a peaceful manner. It has also created a series of relationships that, although challenging to manage on a day-to-day basis, are surprisingly durable in the long run. Whether this will continue to be the case in the future is a major question among strategists today.

The Contemporary Hub-and-Spoke Security System: Risks and Advantages

The alliance system that the U.S. began to construct at the end of World War II is unique in human history and has afforded the United States a number of important strategic and economic advantages. If today’s world is characterized by strategic competitions with other great powers, however, as the 2017 U.S. National Security Strategy suggests, the question becomes whether the U.S. will continue to find that the advantages of the hub-and-spoke system are enough to justify its perpetuation.

The hub-and-spoke system possesses both risks and advantages to the United States that policymakers must consider as they evaluate its contemporary and future utility. The key risks include:

  • Burden-sharing. Questions about whether allies are truly shouldering their collective security responsibilities are perennial in alliance management. In a NATO context, such questions have been raised since the founding of the alliance in 1949. Very few states today spend as much on their defense programs as the United States does, and many NATO allies struggle to meet an agreed-upon goal of 2 percent of gross domestic product (GDP) on defense.30
  • Some would ask what use an alliance is if other states do not have sufficient military capabilities to advance common objectives? Others contend, however, that earlier NATO discussions of burden sharing included the moral dimensions of allied solidarity in the face of an existential expansive Communist threat. According to this view, today’s debates would therefore be better characterized as debates about cost sharing rather than burden sharing. In any event, debates swirl around whether allies are paying their fair share.
  • Entanglement. Within asymmetric alliances, most allies are fearful that the United States will either abandon them in a crisis (abandonment) or involve them in a crisis in a manner that they would not otherwise choose (entrapment). As the Founders warned, entanglement in the affairs of other states and their security challenges is a concern for the United States as well. To what extent are U.S. views of strategy and foreign policy choices influenced by allies and partners? Might we have the same perception of the Russian or Iranian threat were it not for our close allies in those regions? What are the risks of being drawn into a conflict that might prompt nuclear escalation?
  • Inappropriate Security Partnerships. As the hub-and-spoke network of security relationships has expanded in order to prosecute counterterrorism and capacity-building strategies since September 11, 2001, questions have arisen regarding the efficacy of many of these partnerships. At the heart of the issue is whether building security forces in states with fragile governments—by, for example, providing training, equipment, and institutional support—might actually make the United States less secure in the long term.
  • For one thing, partners on the ground may have short-term and long-term interests that are very different from those of the United States and may use their enhanced military capabilities to go beyond the objectives for which the assistance was intended. U.S. security assistance to Mali led to the provision of professional military education and training. A separatist rebellion launched in late 2011 by members of the minority ethnic Tuareg community aggravated intramilitary and political tensions in the country, leading to a military coup by junior officers in March 2012 that was spearheaded by Captain Amadou Sonogo, who had been a recipient of that training,31
  • Strategic Insolvency. Some observers of U.S. defense policy are increasingly concerned that the gap between America’s defense spending and its global responsibilities is widening. According to this view, budget unpredictability exacerbated by the 2011 Budget Control Act (“sequestration”), along with readiness issues, nearly two decades of war, personnel retention, and other factors, has left the DOD ill prepared to meet its own goals as articulated in the 2018 National Defense Strategy. Elements of this argument can be found in theories of imperial overstretch;32 the National Defense Strategy Commission (NDSC) calls it a possibility of “strategic insolvency.”33 Within the foreseeable future, the U.S. may no longer have the capabilities to defend its allies in more than one theater without significantly reinvesting in its defense program, significantly scaling back its level of ambition, or both.34

The principal advantages of the hub-and-spoke system include:

  • Global Reach. One of the key reasons for building the U.S.-led defense architecture in the first place was to be able to fight the nation’s wars far away from the American homeland. This rationale still holds. The United States would not have been able to plan and execute operations around the world like its move into Afghanistan, which occurred within a month after the September 11 terrorist attacks, were it not for its network of military bases and access agreements in the U.S. European Command and U.S. Central Command areas of responsibility.35
  • Lower Costs. Despite the considerable amount of political hay being made from burden-sharing issues, the financial costs that the U.S. would have to shoulder to accomplish its strategic objectives absent its hub-and-spoke system would likely be significantly higher. Allies often facilitate the presence of U.S. forces stationed on their soil through in-kind payments. South Korea, for example, contributed the lion’s share of the costs associated with building Camp Humphreys ($9.7 billion of a $10.8 billion project) and annually pays approximately 50 percent of the nonpersonnel costs for the stationing of U.S. troops.36 Further, historically speaking, imperial predecessors appear to have spent a considerably larger share of their annual budgets on the maintenance of their global military posture.
  • While not a perfect comparison, it is still worth observing that by some estimates, the United Kingdom spent upwards of 37 percent of its annual governmental budget on its military between 1860 and 1914.37 During the same period, the majority of Western European countries, Russia, the U.S., and Japan spent, on average, 32 percent of their annual governmental budgets on their militaries.38 In other words, “[t]axes collected by the British government were used basically to defray military expenditure and to pay interest on a national debt which had accumulated as a consequence of past wars fought to acquire and defend the empire.”39 By comparison, the U.S. spent 14.75 percent of its annual budget (both mandatory and discretionary) on the defense program in 2017.40
  • Exercises and Interoperability. The hub-and-spoke system has created a wide variety of opportunities for U.S. servicemembers to engage with their foreign counterparts to advance strategic, operational, and tactical interests collectively and ensure that servicemembers from different countries can fight together effectively. NATO, for example, has the International Military Staff (IMS) and a series of standardization agreements and exercises that help to improve interoperability among member states and partners. These preparations during peacetime help to build meaningful capabilities that can be drawn upon during crises and conflict.
  • Even though Operation Iraqi Freedom was an ad-hoc coalition, for example, most experts agree that it would not have been possible to operate coherently were it not for NATO’s decades of efforts to improve interoperability among its members, many of which participated in that coalition. Also, many multilateral military exercises occur outside of U.S. territories, which has the additional advantage of giving U.S. servicemembers key opportunities to understand the contours of a theater or battlespace before conflict occurs, which in turn enables better planning and preparation for an outbreak of hostilities.
  • Coalition Participants. Another proven benefit of the hub-and-spoke system has been the willingness of other states to contribute troops, financial resources, or both to U.S.-led military coalitions. At the height of the Afghanistan campaign, 50 nations contributed troops to the International Security Assistance Force.41 Similarly, allies and partners have contributed to U.S.-led wars and operations in Korea, Vietnam, the Persian Gulf, Somalia, the Balkans, Libya, Iraq, and Syria. In addition to defraying the costs in terms of both blood and treasure that are associated with prosecuting these missions, these contributions have also served to underscore their international legitimacy.42

Given this balance sheet of risks and advantages, successive U.S. Administrations have determined that reinvesting in this hub-and-spoke system continues to benefit American interests. The amount of time and attention that day-to-day management of this system entails—on any given day, dozens of tactical-level and strategic-level issues between sovereign states must be juggled based on shifting notions of security and defense that change over time along with strategic circumstances—might suggest to a casual observer that these relationships are fragile, but the historical track record suggests the opposite. The dissolution of the Soviet Union actually led to an expansion of the hub-and-spoke system and has enabled the United States to prosecute expeditionary operations alongside a wide variety of coalition partners.

Looking to the future, however, there are reasons for concern. The U.S.’s key competitors have studied America’s defense strategy or approach to waging war and appear to have concluded that fighting the United States conventionally is a losing proposition. Instead, Russia and China appear to be using a combination of military and nonmilitary tools (such as, for example, Moscow’s seizure of the Crimean Peninsula and Beijing’s assertion of a claim to the nine-dash line territories in the South China Sea) to achieve their objectives.

Another key tactic that these adversaries appear to be using is an attempt to disrupt the U.S.-led hub-and-spoke security network. Due to China’s coercive economic policies, combined with its military reforms and expeditionary presence, some of America’s allies such as Australia are facing a stark strategic choice: whether to invest in a relationship with China or with the United States.43 Others, such as Italy, have determined that no apparent conflict exists between embracing Chinese Belt and Road investments and observing their obligations to the European Union (EU) and NATO.44 Likewise, Russia’s disinformation operations appear to be designed, among other things, to sow doubt in European capitals as to the utility of the institutions that the U.S. has helped to create since World War II, including NATO and the EU.45

Complicating matters, Moscow and Beijing appear to be collaborating to achieve their shared objective of displacing the United States as the center of the hub-and-spoke system. As the 2019 Worldwide Threat Assessment released by the Director of National Intelligence notes, “Russia and China seek to shape the international system and regional security dynamics and exert influence over the politics and economies of states in all regions of the world and especially in their respective backyards.”46

Their apparent objective in doing so is to advance an authoritarian vision of governance and world order.47 This stands in stark contrast to the international order that the United States has fought hard to achieve over the past 70 years and that, on balance, takes human freedom and individual liberty as a starting point for political organization. From this perspective, the strategic stakes could hardly be higher.


Both nature and power abhor a vacuum, and both Beijing and Moscow appear to be happy to fill any space created by a U.S. retrenchment—perceived or actual—from the hub-and-spoke system. The United States therefore appears to be at a crossroads. It can either continue to view its complex network of security relationships through a transactional, cost-sharing lens, or it can instead reconsider the broader strategic value of the hub-and-spoke network as the key mechanism through which Washington can counter its great-power competitors.

Indeed, allies contribute to the U.S. and the furtherance of its interests in any number of ways, and their contributions go beyond mere dollars and cents. Regional access, prepositioning of forces and supplies, political-strategic relationships, and interoperable forces together create a “warm start” in the event of a crisis. Further, the U.S. gains intelligence and situational awareness from its global security relationships that it would not otherwise have.

Perhaps most important, however, by reinvesting in its global web of security relationships, the U.S. simultaneously is sending a message to its competitors that they will not be able to pursue their own arguably coercive agendas unchallenged. Should the U.S. let the hub-and-spoke system languish, the costs of acting alone—in diplomatic, military, and economic terms—are likely to be prohibitive. Compounding the problem, adversaries would likely take advantage of an erosion of U.S. security relations to strengthen their positions at America’s expense.

Despite the hub-and-spoke network’s advantages, just as questions about the appropriate U.S. role in the world remain up in the air, so too does the question of retrenchment from this system versus reinvigoration of it also remain unsettled. At least for now, however, the hub-and-spoke system will undoubtedly remain a foundational element of American strategy—if we choose to keep it.


  1. Any views expressed in this article are strictly those of the author and do not represent the views of any organization with which she is affiliated.
  2. Dwight D. Eisenhower, Crusade in Europe (New York: Doubleday, 1948), p. 4, as quoted in Robert H. Scales, Jr., “Trust, Not Technology, Sustains Coalitions,” Parameters, Vol. 28, No. 4 (Winter 1998–99), (accessed July 13, 2019).
  3. David Fromkin, “Entangling Alliances,” Foreign Affairs, Vol. 48, No. 4 (July 1970), pp. 688–700, (accessed July 13, 2019).
  4. “Hub-and-spoke” is often used to describe the U.S. system of bilateral alliances in Asia, while NATO is referred to as a “multilateral” system. These terms generally refer to formal alliance relationships; as this essay considers the totality of U.S. global security arrangements and how they have evolved over time, “hub-and-spoke” is an appropriate metaphor to describe this complex network of security relationships that has the United States at its center.
  5. Thucydides, The History of the Peloponnesian War, trans. Richard Crawley (London: J.M. Dent, 1910).
  6. George Modelski, “The Long Cycle of Global Politics and the Nation State,” Comparative Studies in Society and History, Vol. 20, No. 2 (April 1978), pp. 214–235.
  7. Kori Schake, Safe Passage: The Transition from British to American Hegemony (Cambridge, MA: Harvard University Press, 2017), esp. Chapter One. The United States has, of course, been imperfect in its application of these values and principles; the U.S. annexed Hawaii, for example.
  8. “It is imperative that [there be] a much more rapid and concerted build-up of the actual strength of both the United States and the other nations of the free world. ¶ The execution of such a build-up, however, requires that the United States have an affirmative program beyond the solely defensive one of countering the threat posed by the Soviet Union. This program must light the path to peace and order among nations in a system based on freedom and justice…. Further, it must envisage the political and economic measures with which and the military shield behind which the free world can work to frustrate the Kremlin design by the strategy of the cold war…. The only sure victory lies in the frustration of the Kremlin design by the steady development of the moral and material strength of the free world and its projection into the Soviet world in such a way as to bring about an internal change in the Soviet system…. ¶ In summary, we must, by means of a rapid and sustained build-up of the political, economic and military strength of the free world, and by means of an affirmative program intended to wrest the initiative from the Soviet Union, confront it with convincing evidence of the determination and ability of the free world to frustrate the Kremlin design of a world dominated by its will….” Conclusions and Recommendations” in NSC 68: United States Objectives and Programs for National Security (April 14, 1950): A Report to the President Pursuant to the President’s Directive of January 31, 1950, National Security Council, April 7, 1950, (accessed July 15, 2019).
  9. World Bank, “History,” (accessed July 15, 2019), and International Monetary Fund, “History: Cooperation and Reconstruction (1944–71), (accessed July 15, 2019).
  10. NSC 68: United States Objectives and Programs for National Security, p. 68.
  11. Stacie L. Pettyjohn, U.S. Global Defense Posture, 1783–2011 (Santa Monica, CA: RAND Corporation, 2012), pp. 49–96, (accessed July 15, 2019). Prepared for the U.S. Air Force by RAND Project Air Force.
  12. Wallace J. Thies, Why NATO Endures (New York: Cambridge University Press, 2009).
  13. U.S. Department of Defense, “Remarks as Delivered by Secretary of Defense Robert M. Gates, The Nixon Center, Washington, D.C., Wednesday, February 24, 2010,” (accessed June 17, 2019).
  14. National Security Strategy of the United States of America, The White House, December 2017, pp. 2–3, (accessed July 15, 2019).
  15. U.S. Department of Defense, Office of the Undersecretary of Defense (Comptroller), Department of Defense Budget Fiscal Year (FY) 2020: European Deterrence Initiative, March 2019, p. 1, (accessed June 17, 2019).
  16. See note 4, supra.
  17. Compounding the confusion, different scholars have sought to categorize them in different, often overlapping ways. Bruce Russett captures this ambiguity well when he lays out how different scholars—Hans Morgenthau and Kalevi J. Holsti—approach the topic of alliances. He explains that Morgenthau categorizes alliances according to whether they are (1) mutual or unilateral; (2) temporary or permanent; (3) operative or inoperative, depending on their ability to coordinate members’ policies; (4) general or limited in their distribution of benefits; and (5) complementary, identical, or ideological in their scope of interest. Holsti, by contrast, organizes alliances along the following lines: (1) the situation in which commitments are to become operational, (2) the type of commitments undertaken, (3) the degree of military cooperation or integration, and (4) the geographic scope of the treaty. Bruce M. Russett, “An Empirical Typology of International Military Alliances,” Midwest Journal of Political Science, Vol. 15, No. 2 (May 1971), p. 264.
  18. Stephen M. Walt, The Origin of Alliances (Ithaca, NY: Cornell University Press, 1987), pp. 12–13, and Glenn H. Snyder, Alliance Politics (Ithaca, NY: Cornell University Press, 2007), p. 4. In Walt’s conception, they can be formal or informal; in Snyder’s, they are formal arrangements.
  19. The major exception to this is Walt’s The Origin of Alliances, which looks at alliance formation in the Middle East from 1955–1979.
  20. There is, of course, an enormous body of post–Cold War work exploring the particular policy and strategic dimensions of key alliance relationships, such as NATO or U.S. bilateral defense relationships in Asia. Yet the insights and assumptions regarding the formation and maintenance of those alliances are often informed by studies of alliances that predate the end of the Cold War (or, in the case of constructivism, very shortly thereafter).
  21. Brett Ashley Leeds, Jeffrey M. Ritter, Sara McLaughlin Mitchell, and Andrew G. Long, “Alliance Treaty Obligations and Provisions, 1815–1944,” International Interactions, Vol. 28, No. 3 (July 2002), pp. 237–260, (accessed July 15, 2019).
  22. Patricia Weitsman, Dangerous Alliances: Proponents of Peace, Weapons of War (Stanford: Stanford University Press, 2004).
  23. Kathleen J. McInnis, How and Why States Defect from Contemporary Military Coalitions (New York: Palgrave Macmillan, 2019).
  24. Ibid.
  25. Glenn Snyder refers to this as the “political penumbra” of alliances. Further, a RAND study notes, “In our analysis of aggregate U.S. bilateral trade, we find solid evidence that U.S. security commitments have significantly positive effects on U.S. bilateral trade. For example…a doubling of U.S. personnel commitments overseas could increase U.S. bilateral trade by as much as 15 percent, depending on the service, while a doubling of treaties could expand U.S. bilateral trade by 34 percent overall.” Daniel Engel, Adam R. Grissom, John P. Godges, Jennifer Kavanagh, and Howard J. Schatz, Estimating the Value of Overseas Security Commitments (Santa Monica, CA: RAND Corporation, 2016), p. x, (accessed July 15, 2019).
  26. North Atlantic Treaty, Article 2, April 4, 1949, last updated April 10, 2019, (accessed July 15, 2019). Emphasis added.
  27. G. John Ikenberry, After Victory: Institutions, Strategic Restraint, and the Rebuilding of Order After Major Wars (Princeton, NJ: Princeton University Press, 2001) pp. 162–214.
  28. Ibid. See also I. M. Destler, “America’s Uneasy Relationship with Free Trade,” Harvard Business Review, April 28, 2016, (accessed June 18, 2019).
  29. Robert E. Harkavy, Bases Abroad: The Global Foreign Military Presence (Stockholm: Stockholm International Peace Research Institute, 1989), p. 5.
  30. Press release, “Wales Summit Declaration Issued by the Heads of State and Government Participating in the Meeting of the North Atlantic Council in Wales,” North Atlantic Treaty Organization, September 5, 2014, (accessed June 18, 2019).
  31. Martin Vogl, “Mali Coup Leaders Partially Reopen Airport,” Associated Press, March 26, 2012, (accessed July 15, 2019), and Simon J. Powelson, Enduring Engagement Yes, Episodic Engagement No: Lessons for SOF from Mali, Thesis, Naval Postgraduate School, Monterey, California, December 2013, p. 56, (accessed June 18, 2019).
  32. Paul Kennedy, The Rise and Fall of the Great Powers (New York: Random House, 1987).
  33. National Defense Strategy Commission, Providing for the Common Defense: The Assessment and Recommendations of the National Defense Strategy Commission, released November 14, 2018, p. xii, (accessed July 15, 2019).
  34. Rick Berger and Mackenzie Eaglen, “‘Hard Choices’ and Strategic Insolvency: Where the National Defense Strategy Falls Short,” War on the Rocks, May 16, 2019. (accessed July 15, 2019).
  35. Council on Foreign Relations, “The U.S. War in Afghanistan: 1999–2019,” CFR Timeline, (accessed July 15, 2019).
  36. Mark E. Manyin, Emma Chanlett-Avery, and Brock R. Williams, “South Korea: Background and U.S. Relations,” Congressional Research Service In Focus No. 10165, updated May 20, 2019, (accessed June 18, 2019), and Christine Kim, “US Forces Chief Says South Korea Paid for 90 Percent of Biggest Overseas Base,” Reuters, June 28, 2018, (accessed June 18, 2019).
  37. Patrick K. O’Brien, “The Costs and Benefits of British Imperialism 1846–1914,” Past & Present, Vol. 120, No. 1 (August 1988), p. 187.
  38. Ibid.
  39. Ibid.
  40. Congressional Budget Office, “The Federal Budget in 2017: An Infographic,” March 2018, (accessed July 13, 2019). Figure derived from calculating the amount of defense spending in 2017 ($590 billion) as a percentage of an overall federal budget of $4 trillion.
  41. North Atlantic Treaty Organization, International Security Assistance Force, “International Security Assistance Force (ISAF): Key Facts and Figures,” October 8, 2012, (accessed June 18, 2019).
  42. Olivier Schmitt refers to this as “legitimacy aggregation.” Olivier Schmitt, Allies that Count: Junior Partners in Coalition Warfare (Washington: Georgetown University Press, 2011).
  43. Neil Irwin, “Australia and the U.S. Are Old Allies. China’s Rise Changes the Equation,” The New York Times, May 11, 2019, (accessed July 15, 2019).
  44. Andrew Chatzky, “China’s Belt and Road Gets a Win in Italy,” Council on Foreign Relations, March 27, 2019, (accessed July 15, 2019).
  45. Daniel R. Coats, Director of National Intelligence, “Worldwide Threat Assessment of the US Intelligence Community,” statement before the Select Committee on Intelligence, U.S. Senate, January 29, 2019, pp. 5–6, (accessed July 15, 2019). See also Todd C. Helmus, Elizabeth Bodine-Baron, Andrew Radin, Madeline Magnuson, Joshua Mendelsohn, William Marcellino, Andriy Bega, and Zev Winkelman, Russian Social Media Influence: Understanding Russian Propaganda in Eastern Europe (Santa Monica, CA: RAND Corporation, 2018), (accessed July 15, 2019).
  46. Coats, “Worldwide Threat Assessment of the US Intelligence Community,” p. 4.
  47. Ibid., pp. 4 and 25.