“No man is an island, entire of itself,” wrote the English poet John Donne in 1624.1 The same is true of nations.

The United States now sits at the apex of an international network of alliances brought together during the Cold War, but this has not always been America’s situation. In earlier times, especially at its inception, the U.S. benefited from alliances, generally as the junior partner. Success in the Revolutionary War was helped by a crucial alliance with France, a country that the infant U.S. shortly thereafter fought in the undeclared Quasi-War (1798–1800).2

It is true that George Washington, in his Farewell Address of 1796, warned his countrymen that they should not “entangle our peace and prosperity in the toils of European ambition,” an admonition that has come to be viewed as a warning against “foreign entanglements.”3 But while he urged Americans to take advantage of their country’s geographical isolation from the world’s troubles, he was not advancing an argument for political isolationism.4 If anything, he was anticipating (and sharing) the sentiment of British Prime Minister Lord Palmerston, who, speaking in the House of Commons on March 1, 1848, avowed that “We have no eternal allies, and we have no perpetual enemies. Our interests are eternal and perpetual, and those interests it is our duty to follow.”5

Washington’s argument, like Palmerston’s, was that no nation, especially a nation as influential at various times as the United States or Great Britain, can disengage from the world. Such a nation must instead be free to choose when to engage and when not to engage—and, most momentously, when to go to war and when to walk away.

Wisdom and Utility of Alliances

An equally spirited debate about the wisdom and utility of alliances continues today. Repeatedly, alliances are referred to as burdens, an elastic term that can be stretched to include everything from moral hazard to free riding.

The burden of moral hazard is that states, including states of roughly equivalent weights, may feel emboldened to pursue riskier foreign policies because their allies are obligated to come to their rescue. Perhaps the most famous example of what is also referred to as “entrapment” was Germany’s alliance with Austria–Hungary before World War I. Emboldened by this alliance and German encouragement, Austria–Hungary felt that it could safely make humiliating demands of Serbia even though Serbia was allied to Russia.6 It was wrong: Russia failed to restrain Serbia and initiated military preparations of its own, the chain gang of alliance obligations snapped into place, and Europe found itself on the way to war.7

The reciprocal of entanglement is abandonment. The U.S., for example, is at risk of being pulled both ways in its relationship with allies in Asia, a concern that Beijing is evidently attempting to use to its own advantage.8

Concerns about free riding, “that America’s allies, especially the smaller ones, have simply been unfair in not bearing large shares of the common burdens,” has bedeviled America’s relations with its allies—especially its NATO allies—for many years.9 In straightforward economic terms, the U.S. does make a greater contribution to alliance resources than other members, and there is a risk that this could become unsustainable during a period when America’s economic power is in relative decline. However, the costs of alliances, including the sometimes disproportionate cost of alliance leadership, must not be weighed against cash savings but rather against the cost of possible conflict in blood as well as treasure without them.10

America’s treaty with France committed it to joining France in war if it was attacked by Great Britain. Since 1792, France had been engaged in its own revolutionary war with its neighbors, including Britain, and the political grouping led by Thomas Jefferson and James Madison was arguing strongly that the United States should fulfill its treaty obligations. Washington, who issued his 1793 Proclamation of Neutrality (subsequently the Neutrality Act of 1794) to avoid this obligation, wrote his address in part to deflect their criticism of his actions.11

The Royal Navy was now much stronger than it had been when it was defeated by the French at the Battle of the Virginia Capes in 1781, the action that had precipitated Cornwallis’s surrender at Yorktown, thus ending the War of Independence. Washington, well aware of Britain’s renewed naval strength, refused to see American trade ravaged and U.S. ports set ablaze.

Unlike Madison, who when President launched the War of 1812 that saw the White House burned and, as the naval historian Alfred Thayer Mahan memorably recorded, grass grow in the streets of Boston as a consequence of the British blockade, America’s first President had no intention of exposing his country to such peril.12 He recognized that the young republic lacked the military wherewithal to deliver on its treaty promise even if it wanted to and assessed that the costs of joining France in a protracted conflict with Great Britain far outweighed any potential benefit for America. The gap in capabilities between the young United States and Britain and the geographic distance separating America from France were simply too great.

The United States and Great Britain concluded no formal military alliance during the 19th century. There were several disagreements, some severe enough on occasion for both sides to contemplate war prior to what historians have called “The Great Rapprochement” between the two beginning in the 1890s,13 but even before that, there was also complementarity in their actions that accorded with the principle of eternal interests rather than eternal allies. For example, the Monroe Doctrine, set forth by President James Monroe in 1823 to prevent European nations from colonizing territory or threatening states in North or South America, might have been largely impossible to implement given the Royal Navy’s ability to intervene when and where it chose.14 Britain, however, elected not to challenge the Monroe’s policy because it accorded with Britain’s interest in ensuring that the disintegrating Spanish empire in the Americas did not fall piece by piece into the hands of its imperial rivals.15

Clearly, America has chosen to engage in or refuse alliance depending on its interests. So what are the benefits of military alliances if, on occasion and between some powers at least, solemn agreements can be ignored, while in other situations, so much can apparently be achieved in their absence?

Alliance Typology

Alliances have been a fact of international political life since antiquity.16 They perform a number of different functions for states, often at the same time, which makes categorization difficult. Nonetheless, their primary function is military, and the three primary classifications used in the academic literature bear this out:

  • Defense pacts, by which signatories are obliged to intervene militarily on the side of any treaty partner that is attacked militarily;
  • Neutrality and non-aggression pacts, which obligate signatories to remain militarily neutral if any co-signatory is attacked (neutrality pacts are usually more specific than non-aggression pacts); and
  • Ententes, by which signatories agree to consult with one another and potentially cooperate in a crisis, including one involving an armed attack.17

The common features shared by all three types of alliances lead to a definition like the one proposed by Stephen Walt: that alliances are formal or informal commitments for security cooperation between two or more states. “Although the precise arrangements embodied in different alliances vary enormously,” Walt argues, “the defining feature of any alliance is a commitment for mutual military support against some external actor(s) in some specified set of circumstances.”18

Viewed in this loose way, alliances can be either formal, written treaties or informal, unwritten agreements based on anything from tacit understandings to verbal assurances. These, however, may be good enough. Formal agreements have often said little about actual commitment. The Franco–American treaty sidestepped by George Washington, for example, provided more assurance that support would be forthcoming than turned out to be the case. The French sense of betrayal was one of the factors that contributed to the Quasi-War. On the other hand, America’s alliance with Britain before Pearl Harbor was largely tacit, even secret, but nonetheless very real.

Alliances exist to advance their members’ collective interests by combining their capabilities—which can be industrial and financial as well as military—to achieve military and political success. How these are combined can vary, as the academic classifications suggest.

The degrees to which alliances are institutionalized also differ. Most alliances throughout history have been loose, often ad hoc arrangements and subject to the vagaries of fortune and commitment. Most European alliances, such as the various coalitions that Great Britain assembled to defeat Napoleon, were of this type.19 The French emperor was defeated only when the coalition participants finally realized that if they were to free themselves from endless conflict, they had to stand together rather than cut deals for short-term advantage.

Ad hoc alliances often contain strange bedfellows. Britain, a constitutional monarchy with laws passed by Parliament, established common cause with autocratic Russia to defeat Napoleon. Similarly, in World War II, the Anglo–American democracies found it necessary, if they were to defeat Nazi Germany, to join forces with Stalin’s totalitarian state, which had been their enemy and would be again. Throughout the conflict, each side was suspicious that the other might cut a separate deal with the German dictator, and the desire to ensure that neither side did so sustained the alliance as much as military capability did. In fact, as Robert Osgood argues, “next to accretion, the most prominent function of alliances has been to restrain and control allies.”20

Most alliances are, to some degree at least, asymmetrical. When it comes to commitments, one signatory may expect less of the other militarily. For example, the 1839 Treaty of London in which Britain guaranteed Belgium’s neutrality, while not a military alliance, was necessarily a one-sided commitment by Britain to come to Belgium’s aid if it was invaded, a commitment that Britain honored in 1914.21

When it comes to capabilities, alliance members can likewise make very different contributions. Britain’s input to the defeat of Napoleon was primarily financial and naval; apart from Arthur Wellesley’s campaign in Spain and victory at Waterloo, few British troops were involved.22 In fact, it was a classic demonstration of how maritime powers achieve their victories.

In World War II, despite the ferocity of the fighting on the Eastern Front and the beaches of Normandy, the war in Europe was won by Anglo–American air and sea power, which crushed Germany’s ability to prosecute the war.23 Arguably, the Red Army would not have prevailed over the Wehrmacht absent the combined bomber offensive and the British convoys that fought to deliver American war matériel to Archangel and Murmansk. Despite Stalin’s bombast and demands for a second front, he was probably aware of this truth.

Cold War Alliances

When the United States considered how the post–World War II world should be organized, it thought first of collective security institutionalized in the United Nations.24 This accorded with its core value of democracy and the liberal ideal that international organizations were a way to transcend national differences and antagonisms. However, in geopolitical terms, the U.N. turned out to be a concert of the great powers that sit on its Security Council, each one of which holds a veto over its decisions. With the sole exception of the Korean War, when a U.N. force under U.S. leadership repelled the North’s invasion of the South in the absence of a Soviet veto, the United Nations was quickly shown to be an inadequate bulwark against Soviet expansion.

Realizing this, the U.S. sought an alternative way to respond to Soviet adventurism, adopting a policy of containing the Soviet Union politically and militarily. This was enunciated in the 1947 Truman Doctrine and formalized in alliance terms with the foundation of the North Atlantic Treaty Organization (NATO), often referred to simply as “the alliance,” in 1949.25

NATO started with relatively modest ambitions that accorded with America’s historical antipathy to entanglements. The initial strategy was for an integrated defense of the North Atlantic area in which the Europeans would contribute the land forces while the American contribution would be confined largely to naval force and strategic bombing.26 However, post-Korea, the alliance rapidly became more complex as the Cold War with the Soviet Union evolved. Maturing into a “highly institutionalized alliance with elaborate decision-making procedures and an extensive supporting bureaucracy” with its own military command structure, it gained the solidity to outlast the defeat of the Soviet Union, its original antagonist, and retain just enough of its military and organizational capability and capacity to oppose that antagonist when it shed its Communist ideology and rediscovered Russian nationalism.27

The arguments for NATO’s creation were several. Perhaps most important, it made clear that a free Europe was a vital American interest and made manifest America’s commitment to Europe’s defense. If Europe had been overrun by Soviet forces, this would have compromised two of America’s eternal interests: retention of its continental integrity by undermining control of the sea and air approaches to America’s eastern seaboard and preventing the Eurasian landmass from being dominated by a single power.28

The arguments against NATO arose out of American ideals:

  • Alliance membership, and especially the commitment to Article Five, allegedly compromised the nation’s freedom of action contrary to the U.S. Constitution in that “an armed attack” against any signatory would “be considered an attack against them all” requiring the provision of all necessary assistance, including the use of armed force.29
  • It also allegedly undermined the United Nations and the principle of collective security by accepting the validity of military alliances and what internationalists regarded as the discredited notion of power balancing.30

Between 1948 and 2014, the United States accumulated some 66 defense commitments,31 including commitments to NATO members (the Washington Treaty of 1949) and adherence to a second, multilateral treaty, the Rio Treaty of 1947,32 which took in most countries in Latin America. The U.S. is also linked in formal alliances to South Korea (with which, like NATO, it shares a military command structure) and Japan, Thailand, the Philippines, Australia, Liberia, and some small Pacific island states that previously were U.S. territories.33

In the 1980s, the U.S. created a new category of alliance called “major non-NATO allies” (MNNA), primarily to ease arms transfers and facilitate military cooperation.34 States in this category include Afghanistan, Argentina, Bahrain, Egypt, Israel, Jordan, Kuwait, Morocco, New Zealand, and Pakistan. In 2015, President Barack Obama announced his intention to designate Tunisia an MNNA. Meanwhile, Congress proposed that Georgia, Moldova, and Ukraine should be extended MNNA status following Russia’s 2014 invasion of Crimea, and President Obama similarly proposed, following a 2015 meeting with the Gulf Cooperation Council, that the same offer should be made to Oman, Qatar, Saudi Arabia, and the United Arab Emirates, presumably to soften the blow of the upcoming nuclear détente with Iran that was signed later that same year.

While it is conceivable that U.S. protection might be extended to some countries on this list if they were attacked, there is no guarantee that any military measures would be forthcoming. The standing of some is particularly problematic: Pakistan, for example, which is still linked to the U.S. by the 1954 Mutual Defense Assistance Agreement but has moved closer to China (while the U.S. has moved closer to Pakistan’s rival, India), and Saudi Arabia, with which the U.S. has close ties but no formal alliance.

The most problematic relationship of all is with Taiwan. U.S. government intentions toward Taiwan have been mired in uncertainty ever since diplomatic recognition was switched from the Republic of China (ROC) to the People’s Republic of China (PRC) on January 1, 1979. Even though this ambiguity has persisted through successive Administrations, the U.S. Congress has always maintained a keen interest in the continuation of contacts and preservation of Taiwan’s status consistent with the will of its people. The Taiwan Relations Act came into force in 1979 to govern unofficial relations between the two states. Official military relations, however, were essentially ended on January 1, 1980, when the U.S. terminated the U.S.–ROC Mutual Defense Treaty.

Post–Cold War Changes

Two trends characterize the period since the fall of the Soviet Union:

  • NATO’s enlargement and search for a new raison d’etre and
  • The preference for “coalitions of the willing.”

The fall of the Berlin Wall in 1989 triggered a wave of popular uprisings that drove Communist regimes from power across Central and Eastern Europe, culminating in the dissolution of the Soviet Union itself in December 1991. Even before the final collapse occurred, NATO’s counterpart in the East, the Warsaw Pact, had disbanded itself at a ministerial meeting held in Budapest in February 1991.

Historically, when a threat disappears, the military alliance assembled to confront it folds its tent and leaves. Instead, and almost instinctively, all of NATO’s member governments felt that the alliance should continue without, as Stanley Sloan put it, being “fully agreed as to why.”35 Some officials argued that it was more than a military alliance: It was a community of values transcending any specific military threat. Others were more specific, suggesting that although the Soviet Union was going through its death throes and the Russia that was reemerging appeared to be moving closer to the West, this could change, and Russia could adopt a threatening posture in the future. Finally, and most broadly, NATO was a source of stability. The investment that had been made in physical infrastructure and the pooling of organizational and cooperative experience was too good an insurance policy against future threats to European security to let go.

However, events in the 1990s unsettled alliance relations.

  • The first event was NATO’s initial post–Cold War Strategic Concept. Issued in 1991, it emphasized a broader approach to security. In effect, the alliance now needed to manage not one but two core missions: collective defense and “out of area” security tasks ranging from crisis response to military-to-military engagement, which together were more complex militarily and diverse politically than its previously singular Cold War purpose.36
  • The second, enlargement of the alliance by the admission of previously Warsaw Pact powers, was a source of contention from the very beginning. While it removed the stain of Yalta, the U.S. was concerned that it would strengthen nationalist factions in Russia that were already suspicious of Western intentions.37 These reservations were to be borne out when Russia invaded Crimea and the Ukraine in 2014. In addition, the populations of Central and Eastern Europe that had direct experience of Communist and Russian rule were adamantly opposed to the idea that Russia was entitled to absorb them into a sphere of influence simply to appease its own historic sense of insecurity and great-power entitlement.
  • The third was the wars in Bosnia and Kosovo that gave the world the term “ethnic cleansing” as Croats and particularly Serbs used violence to disaggregate ethnically mixed communities with the aim of creating ethnically homogeneous and contiguous areas. Although both conflicts were precisely the type that NATO’s new strategy was intended to defuse, failures in the alliance’s performance on the ground—particularly its inability to prevent the genocide committed at Srebrenica in 1995—pushed America to implement a bombing campaign that drove the warring factions to sign the Dayton Accords by the year’s end.38

Differences between Europeans and Americans, particularly over the Balkan wars, became so acute that, Lawrence Kaplan suggests, the sides drew as far apart as they had been during the Suez–Hungarian Uprising crises of 1956.39 All that held them together was their representation on the Contact Group, a diplomatic device quite separate from NATO that had been created originally to give a voice to Russia in recognition of its traditional role as Serbia’s ally.40 These divisions effectively paved the way for America’s adoption of so-called coalitions of the willing in the early years of the 21st century.

Alliance Management

All great powers that have entered into alliances have encountered problems that have required sometimes enormous diplomatic skills to overcome. An overwhelming external threat often concentrates allied minds, but not always: The British assembled five coalitions against revolutionary France and Napoleon before the sixth defeated him not once but twice. The difference was political maturity. As Richard Hart Sinnreich has written:

The cohesion of any coalition depends on each participating nation’s self-restraint, above all that of the most powerful…. That self-restraint is the more necessary the closer the coalition comes to achieving its military objectives, when the proximity of victory tempts the stronger power or powers to go it alone rather than accommodate the inconvenient preferences of weaker partners…. In repeatedly subordinating the desirable to the attainable without forfeiting the central aim of a Europe free of domination by a single untrammeled will, the authors of the Sixth Coalition revealed statesmanship of a high order.41

The United States managed its Cold War alliances, for the most part, with great skill, but it was helped by the fact that it faced a great threat:

As long as the Soviet arsenal of nuclear weapons and superior manpower on the ground remained in place NATO’s solidarity was assured…. Notwithstanding mutual displays of annoyance, Europeans regarded the American commitment to the Alliance for almost two generations as a guarantee of stability in the West.42

That sense of overwhelming danger was not strong enough in Asia to prevent the Southeast Asia Treaty Organization (SEATO) from dissolving itself in 1977. It had also dissipated in much of Europe by 1992 when the Balkan Wars broke out, leading to a reawakening of the belief that collective security was preferable to collective defense. For some states, including at that point the United States, Operation Desert Storm in 1991 was a powerful reassertion of the importance of the U.N. and a model for what could be achieved in a world that elevated collective security above narrow state interests. There was even a sense that, potentially, the door was now open for the U.N. Security Council to reassert the military role that the antagonism between the great powers (with one opportunistic exception) had rendered impossible for 45 years.

By 1998, the United States was exploring how, under certain circumstances, the alliance could extend its mandate beyond collective defense in the absence of a U.N. mandate. The 1991 Gulf War, for example, had been mandated by the U.N., but the main players involved in the fighting had been NATO powers, and while the coalition formed specifically for the war was an ad hoc creation, the whole campaign had given the impression of a NATO operation.

These discussions, which took place in the context of a planned revision of NATO’s Strategic Concept, were caught up in the controversy over NATO’s role in the Kosovo War. Although in the end, and in the face of the threatened Russian and Chinese vetoes, the operation went ahead without U.N. approval, France insisted that NATO continue to acknowledge the primacy of the Security Council and, in the European context, the “essential role” of the Organization for Security Cooperation in Europe (OSCE), which had been established to monitor compliance with the 1975 Helsinki Accords. Despite this, the door was left open for the allies to operate without a U.N. mandate in the future.43 Thus, America’s membership in NATO has given it options to act with partners even in cases where broader consent or support vis-à-vis the U.N. is problematic.

The September 11, 2001, terrorist attacks on the United States triggered a powerful reaction from the international community and among America’s alliance partners.

  • The U.N. Security Council passed two separate resolutions condemning terrorism;
  • NATO invoked Article Five (an attack on one is an attack on all) for the first time in its history;
  • The NATO–Russia Permanent Joint Council condemned the attacks and promised to cooperate;
  • Australia invoked the Australia–New Zealand–United States (ANZUS) Pact and instructed Australian personnel to deploy with U.S. forces as necessary;
  • The Organization of American States (OAS) invoked the Rio Treaty; and
  • Japan departed from post–World War II practice by authorizing its self-defense forces to assist U.S. forces, albeit in a limited number of non-combatant roles.

America’s efforts over many years to foster wide-ranging alliances in various forms and with a multitude of partners resulted in an outpouring of support from friends around the world. The U.S. declined most of these offers of support, and this rebuff went down especially poorly with several NATO partners in Europe. The reasons were certainly not straightforward. The Washington Times reported that, “according to Undersecretary of Defense Douglas Feith, the United States was so busy developing its war plans in the early stage of the conflict that it did not have time to focus on coordinating Europe’s military role.”44 In the same article, NATO expert Stanley Sloan was quoted as saying that Washington “may have been wrong about the potential utility of at least making a nod in the direction of the NATO offer and using it as a platform for future construction of a more relevant role for the alliance.”45

The real reason may have been that, scared by their experiences working with NATO in the Balkans, U.S. officials were reluctant to be drawn into a ponderous and consensual decision-making process, while the political leadership viewed NATO’s offer as a thinly veiled attempt to gain some sort of institutional control over its response to the attacks.46 However, the U.S. did make immediate use of NATO E-3 surveillance planes to monitor American domestic air space and in 2003 gave NATO command of the (by then United Nations-mandated) International Security Assistance Force (ISAF) in Afghanistan.47

Coalitions of the Willing

It has always been necessary to measure the cost of alliances against their advantages. By the first decade of the 21st century, the United States appeared to view the costs of formal alliances as too high. The gulf that emerged in the 1990s between America’s technological capabilities and those of every one of its allies was in some cases so big as to be unbridgeable. U.S. forces struggled to be able to work with some of them. On top of that, some allies no longer valued a U.S. connection as highly as they once did because the threats they faced appeared to them to be less serious.

To long-standing American complaints of allied free riding—letting the U.S. pay for their defense so that they could spend money on social welfare or economic projects—was added a new complaint: If alliance memberships do not help to ensure that allies do not actively oppose U.S. policy decisions, what are they good for?48 Arguments with European allies over Bosnia and Kosovo, for example, or U.S. withdrawal from the Philippines in the years following the fall of Ferdinand Marcos, or the continuing opposition to the U.S. base footprint on Okinawa all left question marks in American minds about the value of formal alliances.

Alliances are inseparable from their contexts. The world was changing. The context was no longer the Fulda Gap but events in far-off places that, while they concerned the world’s sole surviving superpower, could be of little relevance to other members of the alliance or, for that matter, any static, geographically specific grouping of states. The fear that a spark in some distant brushfire war could ignite a global conflagration had gone. But America could not be so sanguine, and when attention switched to the Middle East, what it needed was not battle tanks but basing rights everywhere from Saudi Arabia to Uzbekistan.49

In November 2002, President George W. Bush announced at a NATO summit that the United States would lead a “coalition of the willing” if Iraqi President Saddam Hussein refused to surrender his weapons of mass destruction (WMD).50 The model was akin to the sheriff’s calling for a posse: It was the mission that decided the coalition, not the coalition that decided the mission. If NATO could not be persuaded to support U.S. foreign policy objectives in Iraq en bloc, then individual members could band together in a coalition whose legitimacy in this case derived from the fact it was made up of free, democratic states. However, that was not essential: All that was required was a common interest or perception of the threat perception and a willingness to do something about it.

Another coalition of the willing but not a military alliance is the Proliferation Security Initiative (PSI), also initiated in 2002. It has now been endorsed by 105 countries interested in preventing the spread of WMD.51

Such coalitions, military or otherwise, are “limited associations of convenience [that leave] countries free to pick and choose specific issues, locations and moments for cooperation based on their individual calculations of the national interest” without requiring them to subscribe to any set of common values or political philosophy.52 They put Realpolitik at the service of America’s predominant liberal internationalism, reinforcing the point that states do not have eternal allies, only eternal interests.

What coalitions of the willing do not do, as Kurt Campbell has pointed out, is institutionalize and encourage habits of cooperation and deep engagement, characteristics that embodied NATO’s operating style during the Cold War and America’s formal alliances like those with Japan and South Korea.53 Relying exclusively on global coalitions of the willing may give the United States maximum flexibility, but it will be in exchange for an increased share of the military burden.54 In Europe and perhaps in Asia, where political and military burdens can and should be shared, it may therefore be premature to call time on alliances, which for nearly three-quarters of a century have been among America’s greatest strategic assets.

Alliances: America’s Great
Strategic Advantage

Since 1941, “alliances have proven to be a crucial and enduring source of advantage for the United States.”55 How so?

  • Alliances prevent war. Not every war, of course, but by driving up the cost of aggression, defensive alliances have an effective record of deterring revanchist states from using violence as a means of settling disputes or gambling on a quick military thrust to achieve relatively risk-free advantage. History suggests strongly that states with allies are less at risk of attack than those without them, an observation borne out by the success of U.S. alliances during the Cold War.
  • This does not mean that aggressors will refrain from using other means to achieve their objectives; in fact, they already are doing so, and campaigns designed deliberately to remain below the level of violent confrontation are likely to become more common. General Valery Gerasimov, chief of the Russian General Staff, has observed that in recent conflicts, non-violent measures occurred at a rate of four to one over military operations and that objectives previously viewed as attainable by direct military action alone could now be achieved by combining organized military violence with a greater emphasis on economic, political, and diplomatic activity.56 Defensive alliances will therefore need to extend the breadth of their activities to avoid being outflanked by opponents that use unconventional means to acquire political advantage.
  • Alliances control rivals. The United States is first and foremost an air and naval power. It wins its wars by retaining control of its own movement and access to supply and denying similar freedom to its adversary. To do that successfully requires a global network of bases and the ability to control the world’s key chokepoints. Geography and the current U.S. basing structure mean that China, Iran, and Russia are likely to be bottled up in any future conflict—although China’s recent island-building activity in the South China Sea reveals a determination to secure its trade routes to the south and west and overcome what has been termed its “Malacca dilemma,”57 and using non-military means has enabled it to confuse and blunt an effective U.S. and allied response to this expansion.
  • Alliances control allies. Entrapment is a concern for any dominant alliance partner. Germany failed to restrain Austria–Hungary in 1914—indeed, encouraged it to act quickly to win what it expected would be a short war. This risk makes management of alliance relations essential, something at which the U.S. has proved to be remarkably adept. Conversely, the U.S. has felt constrained on occasion by its alliance partners, but mostly when they were being asked to operate in ways that were removed from the alliance’s primary task.
  • Alliances enable balancing. When regional states attempt to disrupt the status quo, smaller regional states will either balance against it in an effort to retain their independence or join it (“bandwagon”) in an attempt to curry favor and, by being seen as friends, retain sufficient influence over its actions to limit damage to their own interests. A core of U.S. allies in each region can act as a center of attraction around which balancing can be built, as is occurring now in East Asia. Without them, the sole option for regional powers may be to bandwagon with the regional aggressor.
  • Alliances prevent alliance formation by others. Most of the world’s military powers are members of U.S. alliances. If these alliances did not exist or were abandoned, states would almost inevitably be drawn closer to China, Russia, and Iran and possibly into alliances in active opposition to the United States.
  • Alliances control the bulk of the world’s military power. The nations that are allied with the U.S. spend around $1 trillion on defense (about 62 percent of global military expenditure) and have 6 million people (31 percent of their populations) under arms. China, Iran, and Russia collectively spend roughly 17 percent of global defense expenditure and are able to draw upon around 19 percent of global military manpower (roughly 3.7 million people under arms).58
  • Alliances can hold the line. In a multipolar world in which a reduced U.S. defense establishment might have to face multiple threats, strong and confident allies can hold the line even if they may not be able to roll back the aggression by themselves. This allows the U.S. time to prioritize threats and respond when it is able to do so.
  • Alliances facilitate global power projection. The United States is isolated geographically behind two great oceans. To be able to exert power in Asia, the homeland of revanchist power, it requires bases in Europe, the Middle East, and East Asia. From these bases, it can exert influence and power where and when it needs to do so and in small packets early on to deter and prevent challenges from arising that later could be defeated only by the application of overwhelming force. The notion that the United States could mount a campaign using long-range U.S.-based air power or the concept of prompt global strike alone is based on a misunderstanding of what both capabilities are designed to achieve.59
  • Alliances are the cost-effective option. Preserving peace and sustaining the global political and economic system’s current U.S. orientation can be achieved most cost-effectively with allied support. The alternatives would call for either the maintenance of a huge U.S. military presence overseas far in excess of what is being maintained now or the holding of substantial forces in readiness at home in case the need arose to fight their way back into Europe or Asia to confront trouble in support of what is called “offshore balancing.”60
  • Alliances enhance international legitimacy. They mean that the United States never has to walk alone. When it resists aggression, it is able to do so with the moral authority of the free world.

The U.S., Allies, and a Free World

The free world: a phrase that unfortunately has dropped out of fashion since the end of the Cold War yet is as relevant as ever. China, Iran, and Russia are revanchist powers. All three aim to revise the existing order in their respective regions unilaterally and at the least possible political and military cost to themselves. America is the leader of the free world, and revanchist powers know that if they are to succeed, they must diminish U.S. power globally and undermine the tenets of the current, American-led global order.

Each successful step they take along that path diminishes U.S. security and the security of U.S. partners and allies who accept the current global order as one that serves their own political and economic interests as much as it serves those of the U.S. To achieve their aims, the leaders of China, Iran, and Russia are suppressing individual liberty in their own countries, isolating their populations from information that undermines their control, and concentrating power in their own hands. America has seen the world darken this way before and knows that a darker world is one in which conflict is more likely.

That conflict is arguably underway already: China, Iran, and Russia all act as if it is. In such circumstances, as Winston Churchill put it memorably in 1945, “There is only one thing worse than fighting with allies, and that is fighting without them.”61


  1. John Donne, Devotions Upon Emergent Occasions, Meditation XVII (London, 1624), p. 108, 
http://www.gutenberg.org/files/23772/23772-h/23772-h.htm (accessed May 17, 2016). 

  2. U.S. Department of State, Office of the Historian, “The XYZ Affair and the Quasi-War with France, 1798–1800,” 
https://history.state.gov/milestones/1784-1800/xyz (accessed March 14, 2016). 

  3. For a full account of Washington’s Farewell Address, see Matthew Spalding and Patrick J. Garrity, A Sacred Union of Citizens: George Washington’s Farewell Address and the American Character (Lanham, MD: Rowman & Littlefield, 1996). 

  4. Mark P. Lagon and Michael Lind, “American Way: The Enduring Interests of U.S. Foreign Policy,” Policy Review, No. 57 (Summer 1991), pp. 38–44, http://www.unz.org/Pub/PolicyRev-1991q3-00038 (accessed May 17, 2016). 

  5. Henry John Temple, 3rd Viscount Palmerston, “Remarks in the House of Commons Defending His Foreign Policy,” Hansard’s Parliamentary Debates, 3rd Series, Vol. 97, Col. 122, March 1, 1848, http://www.bartleby.com/73/42.html (accessed May 17, 2016). 

  6. James M. Lindsay, “TWE Remembers: Austria–Hungary Issues an Ultimatum to Serbia,” Council on Foreign Relations, The Water’s Edge, July 23, 2014, http://blogs.cfr.org/lindsay/2014/07/23/twe-remembers-austria-hungary-issues-an-ultimatum-to-serbia/ (accessed May 17, 2016). 

  7. Kenneth N. Waltz, Theory of International Politics (Boston: McGraw-Hill, 1979), p. 167. 

  8. Joseph A. Bosco, “Entrapment and Abandonment in Asia,” The National Interest, July 8, 2013, 
http://nationalinterest.org/commentary/entrapment-abandonment-asia-8697 (accessed May 7, 2016). 

  9. Mancur Olson, Jr., and Richard Zeckhauser, “An Economic Theory of Alliances,” Memorandum RM-4297-ISA, “Prepared for: The Office of the Assistant Secretary of Defense/International Security Affairs,” RAND Corporation, October 1966, 
https://www.rand.org/content/dam/rand/pubs/research_memoranda/2007/RM4297.pdf (accessed May 8, 2016). 

  10. Jakub J. Grygiel and A. Wess Mitchell, The Unquiet Frontier: Rising Rivals, Vulnerable Allies, and the Crisis of American Power (Princeton, NJ: Princeton University Press, 2016), p. 125. 

  11. The U.S. was also engaged in the negotiations that resulted in the Jay Treaty of 1794, which established trade relations with Great Britain, resolved some outstanding military and debt issues left over the from the 1783 Treaty of Paris that had formally concluded the Revolutionary War, and is credited with averting potential war between the two countries. This treaty was also opposed by Jefferson. For more information, see George Washington, letter to Thomas Jefferson, April 12, 1793, in The Writings of George Washington, Vol. X, Part 4, ed. Jared Sparks (Boston: Russell, Shattuck, and Williams, 1836), p. 336. 

  12. Alfred Thayer Mahan, Sea Power in Its Relations to the War of 1812, Vol. II (London: Sampson Low, Marston and Co., 1905), 
pp. 201–214. 

  13. Bradford Perkins, The Great Rapprochement: England and the United States, 1895–1914 (New York: Atheneum, 1968). 

  14. James Monroe, Seventh Annual Message to Congress, December 2, 1823, in The Writings of James Monroe, Vol. VI, ed. Stanislaus Murray Hamilton (New York: G. P. Putnam’s Sons, 1902), p. 328. 

  15. John H. Schroeder, Shaping a Maritime Empire: The Commercial and Diplomatic Role of the American Navy, 1829–1861 (Westport, CT, and London: Greenwood Press, 1985), pp. 15–16, 165–185. See also Lagon and Lind, “American Way: The Enduring Interests of U.S. Foreign Policy,” p. 43. 

  16. Two of the most famous examples are perhaps the Delian League, which evolved into the Athenian Empire, and the Peloponnesian League, made up of Sparta and its allies, which contested the Peloponnesian War between 431 and 404 BC. For more information, see “Peloponnesian War,” Livius, last modified March 28, 2016, 
http://www.livius.org/articles/concept/peloponnesian-war/ (accessed May 17, 2016). 

  17. J. David Singer and Melvin Small, “Formal Alliances, 1815–1939: A Quantitative Description,” Journal of Peace Research, Vol. 3, 
No. 1 (March 1966), p. 5. 

  18. Stephen M. Walt, “Why Alliances Endure or Collapse,” Survival, Vol. 39, No. 1 (Spring 1997), p. 157. 

  19. Richard Moore, “Coalitions Against France,” Napoleonic Guide, 1999, http://www.napoleonguide.com/coalitions.htm 
(accessed May 17, 2016). 

  20. Robert E. Osgood, Alliances and American Foreign Policy (Baltimore: Johns Hopkins Press, 1968), p. 22. 

  21. Daniel Barry, “Centenary Countdown: Britain Declares War on Germany After Violation of Belgian Neutrality,” Centenary News, August 4, 2013, http://www.centenarynews.com/article?id=1005 (accessed May 17, 2016). 

  22. Richard Moore, “The Naval War,” Napoleonic Guide, http://www.napoleonguide.com/navyind.htm (accessed May 17, 2016). 

  23. Phillips Payson O’Brien, How the War Was Won (Cambridge, UK: Cambridge University Press, 2015). 

  24. Collective security exists when all states pledge to defend the security of all other states under international law. Collective security arrangements are systemic. They involve all—or almost all—states that constitute an international system. Axiomatically, the threats they seek to prevent arise for the most part from within the system, not externally. The United Nations is a collective security system. It and systems like it are not alliances. In contrast, collective defense arrangements are alliances whose members pledge to defend all other members from collectively acknowledged attack arising from outside the alliance. In practice, collective defense arrangements work to defuse disagreements between members in order to maintain internal cohesion. 

  25. North Atlantic Treaty Organization, “A Short History of NATO,” http://www.nato.int/history/nato-history.html 
(accessed May 17, 2016). 

  26. Osgood, Alliances and American Foreign Policy, p. 43. 

  27. Walt, “Why Alliances Endure or Collapse,” p. 157. 

  28. Lagon and Lind, “American Way: The Enduring Interests of U.S. Foreign Policy,” pp. 41 and 42. 

  29. The North Atlantic Treaty, Art. 5, April 4, 1949, last updated March 21, 2016, 
http://www.nato.int/cps/en/natolive/official_texts_17120.htm (accessed May 17, 2016). 

  30. John J. Mearsheimer, “The False Promise of International Institutions,” International Security, Vol. 19, No. 3 (Winter 1994–1995), 
pp. 5–49, http://mearsheimer.uchicago.edu/pdfs/A0021.pdf (accessed May 17, 2016). 

  31. Michael Beckley, “The Myth of Entangling Alliances: Reassessing the Security Risks of U.S. Defense Pacts,” International Security, Vol. 39, No. 4 (Spring 2015), pp. 22–24, http://www.mitpressjournals.org/doi/pdfplus/10.1162/ISEC_a_00197 
(accessed June 1, 2016). 

  32. Inter-American Treaty of Reciprocal Assistance (Rio Treaty), September 2, 1947, http://www.state.gov/p/wha/rls/70681.htm (accessed May 17, 2016). 

  33. U.S. Department of State, “U.S. Collective Defense Arrangements,” http://www.state.gov/s/l/treaty/collectivedefense/ 
(accessed May 17, 2016). 

  34. 22 CFR §120.32—Major Non-NATO Ally. 

  35. Stanley R. Sloan, NATO, the European Union, and the Atlantic Community: The Transatlantic Bargain Reconsidered (Lanham, MD: Rowman & Littlefield, 2003), p. 88. 

  36. Ibid., pp. 89–93, 110–114. 

  37. U.S. Department of State, Office of the Historian, “The Yalta Conference, 1945,” 
https://history.state.gov/milestones/1937-1945/yalta-conf (accessed June 7, 2016). 

  38. Sloan. NATO, the European Union, and the Atlantic Community, pp. 93–97. 

  39. Lawrence S. Kaplan, The Long Entanglement: NATO’s First Fifty Years (Westport, CT: Praeger, 1999), p. 189. 

  40. Ibid., pp.190–192. 

  41. Richard Hart Sinnreich, “Preserved by Friend and Foe Alike: The Sixth Coalition Against Revolutionary France,” Chapter 4 in Peter R. Mansoor and Williamson Murray, Grand Strategy and Military Alliances (Cambridge, UK: Cambridge University Press, 2016), 
pp. 106–107. 

  42. Kaplan, The Long Entanglement, p. 186. 

  43. Sloan, NATO, the European Union, and the Atlantic Community, pp. 107–108. 

  44. Louis R. Golino, “NATO Seen Adapting to Terror War,” The Washington Times, August 18, 2002, 
http://www.washingtontimes.com/news/2002/aug/18/20020818-040846-1541r/?page=all (accessed May 18, 2016). 

  45. Ibid. 

  46. Karsten Jung, “Willing or Waning? NATO’s Role in the Age of Coalitions,” World Affairs, Vol. 174, No. 6 (March/April 2012), 
http://www.worldaffairsjournal.org/article/willing-or-waning-nato%E2%80%99s-role-age-coalitions (accessed March 22, 2016). 

  47. North Atlantic Treaty Organization, “NATO and Afghanistan,” last updated December 8, 2015, 
http://www.nato.int/cps/en/natohq/topics_8189.htm (accessed March 21, 2016). 

  48. Bruno Tertrais, “The Changing Nature of Military Alliances,” The Washington Quarterly, Vol. 27, Issue 2 (Spring 2004), p. 142. 

  49. Jung, “Willing or Waning?” 

  50. George W. Bush, “Press Conference by US President George W. Bush and Vaclav Havel, President of the Czech Republic,” Castle Prague, Prague, Czech Republic, November 20, 2002, http://www.nato.int/docu/speech/2002/s021120b.htm 
(accessed May 18, 2016). 

  51. U.S. Department of State, Undersecretary for Arms Control and International Security, Bureau of International Security and Nonproliferation, “Proliferation Security Initiative,” http://www.state.gov/t/isn/c10390.htm (accessed May 18, 2016). 

  52. Jung, “Willing or Waning?” 

  53. Kurt M. Campbell, “The End of Alliances? Not So Fast,” The Washington Quarterly, Vol. 27, Issue 2 (Spring 2004), pp. 161 and 162. 

  54. Ibid. 

  55. Evan Braden Montgomery, “Reshaping America’s Alliances for the Long Haul,” Center for Strategic and Budgetary Assessments, Strategy for the Long Haul Series, June 1, 2009, p. vii, 
http://csbaonline.org/publications/2009/06/reshaping-americas-alliances-for-the-long-haul/ (accessed May 18, 2016). 

  56. András Rácz, “Russia’s Hybrid War in Ukraine: Breaking the Enemy’s Ability to Resist,” Finnish Institute of International Affairs Report No. 43, June 16, 2015, pp. 36–37, http://www.fiia.fi/en/publication/514/russia_s_hybrid_war_in_ukraine/ 
(accessed June 9, 2016). 

  57. Marc Lanteigne, “China’s Maritime Security and the ‘Malacca Dilemma,’” Asian Security, Vol. 4, No. 2 (2008), pp. 143–161. 

  58. Military personnel figures refer to active-duty forces and are taken from International Institute for Strategic Studies, The Military Balance: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2016). Expenditure figures are taken from Stockholm International Peace Research Institute, SIPRI Military Expenditure Database, “Military Expenditure by Country, in Current US$ m., 1988–2015,” http://www.sipri.org/research/armaments/milex/milex_database (accessed June 6, 2016). 

  59. Amy F. Woolf, “Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues,” Congressional Research Service Report for Congress, February 24, 2016, https://www.fas.org/sgp/crs/nuke/R41464.pdf (accessed May 18, 2016). 

  60. Benjamin Schwarz and Christopher Layne, “A New Grand Strategy,” Atlantic Monthly, Vol. 289, No. 1 (January 2002), pp. 36–42. 

  61. Field Marshal Lord Alanbrooke, War Diaries 1939–1945, ed. Alex Danchev and Dan Todman (London: Weidenfeld & Nicolson, 2001), p. 680.