What Are America's Alliances Good For?

Reevaluating Diplomatic & militaRy poweR

What Are America’s Alliances Good For?

Hal Brands and Peter D. Feaver

ABSTRACT: The costs and risks associated with America’s military

alliances have always been more visible and easily understood than

the benets. In reality, however, those costs and risks are frequently

overstated, whereas the benets are more numerous and signicant

than often appreciated. This article offers a more accurate net

assessment of America’s alliances in hopes of better informing

current policy debates.

resident Donald Trump has shaken up the foreign policy debate

in the United States, and nowhere more so than in relations

with America’s longstanding treaty allies. Since Trump emerged

as a presidential candidate in mid-2015, he has often put US alliances

squarely in his crosshairs. Trump labeled the North Atlantic Treaty

Organization (NATO) “obsolete” and suggested leaving its easternmost

members to defend themselves. He oated the idea of encouraging

nuclear proliferation by Japan and South Korea to enable US geopolitical

retrenchment. As president, Trump pointedly refused to explicitly afrm

America’s Article 5 commitment at his rst NATO summit, and he

publicly dressed down the European allies for failing to spend more

on defense.

In a subsequent trip to Europe, Trump offered a more robust

statement of US commitment to NATO, but nonetheless vented

his frustration with allies for not, in his view, shouldering sufcient

burdens.

Underlying these critiques has been the idea that US alliances

are fundamentally sucker bets—one-sided relationships in which a

guileless America bears all the costs and parasitic allies derive all the

benets. “We’re taken advantage by every nation in the world virtually,”

Trump commented in February 2017.

Not surprisingly, the bipartisan US foreign policy elite has generally

reacted with alarm at the administration’s rhetoric and policies. Leading

commentators have warned that Trump is threatening to harm the

alliances Washington spent decades building, institutions generally

considered to be among America’s most precious geopolitical assets.

Likewise, international observers have worried that the United States

1 See, variously, Aaron Eglitis, Toluse Olorunnipa, and Andy Sharp, “Trump’s NATO

Skepticism Raises Alarm for Allies Near Russia,” Bloomberg, July 21, 2016; Stephanie Condon,

“Donald Trump: Japan, South Korea Might Need Nuclear Weapons,” CBS News, March 29, 2016;

and Jeremy Diamond, “Trump Scolds NATO Allies over Defense Spending,” CNN, May 25, 2017.

2 Abby Phillip and John Wagner, “In Poland, Trump Reafrms Commitment to NATO, Chides

Russia,” Daily Herald (Chicago), July 6, 2017.

3 Lauren Gambino and Sabrina Siddiqui, “Trump Defends Chaotic Foreign Policy: ‘We’re

Going to Straighten It Out, OK?’,” Guardian, February 2, 2017.

4 See, for instance, Dov Zakheim, “Trump’s Position on Treaty Commitments Has Already

Hurt America,” Foreign Policy, July 22, 2016.

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47(2) Summer 2017

seems to be turning away from its most important friends.

Yet despite

the reaction they have provoked, Trump’s critiques have nonetheless

revealed a fundamental asymmetry in the cost-benet assessment

of US alliances.

The fact of the matter is that the costs and risks associated with

America’s alliances have always been more visible and easily understood

than the benets. Moreover, because US foreign policy elites have

long become accustomed to military alliances as facts of geopolitical

life, even proalliance observers often struggle to specify, in concrete

terms, why those institutions are so valuable. Supporters are thus at a

rhetorical disadvantage in these arguments. They often defend alliances

by pointing to vague and ill-dened benets, or simply by invoking

tradition, whereas critics can point to specic dangers and burdens,

including those more easily reduced to a campaign trail slogan or a pithy

tweet. And Trump is not alone in his attacks on US alliances—many

leading “realist” academics have long offered similar critiques, which

the president has now effectively appropriated as his own. “The U.S.

net gain from its alliance relationships is . . . not commensurate with the

cost,” Barry Posen writes: “the bargain has become unprotable to the

United States.”

In this essay, we offer a more accurate net assessment of America’s

alliances by detailing the purported costs and considerable—if less

widely understood—benets. We rst summarize the most common

critiques of US alliances and explain why many of those critiques are less

persuasive than they initially seem. We then provide a detailed typology

of the myriad benets—military and otherwise—of US alliances. As this

analysis shows, the net assessment of US alliances is strongly positive,

and the balance is not even particularly close. Today as always, there

remain signicant challenges associated with alliance management and

reasonable debates to be had about addressing them. But those debates

need to be informed by a better understanding of what US alliances are

good for in the rst place.

Costs, Real and Perceived

Trump is not the rst prominent observer to critique US alliances.

Ever since the country’s founding, permanent military alliances have

been a source of controversy. The alliance structure built from the ashes

of World War II, and gradually expanded in the decades thereafter, has

itself been the subject of heated debate. Leading political gures such

as Senator Robert Taft initially opposed an American commitment to

NATO; Senator Michael Manseld sought to force withdrawal of half

the US troops deployed to Europe in the early 1970s. The post-Cold

War expansion of NATO touched off perhaps the most intense foreign

policy debate of the 1990s. And in recent decades, there has been a lively

cottage industry among academics who deem US alliances expensive,

unrewarding, and dangerous, and who argue for attenuating or simply

abandoning those commitments. The standard academic critique—much

5 Krishnadev Calamur, “Germany’s Merkel Urges ‘Europe to Take Our Fate into Our Own

Hands,’ ” Atlantic, May 30, 2017.

6 Barry R. Posen, Restraint: A New Foundation for U.S. Grand Strategy (Ithaca, NY: Cornell

University Press, 2014), 34.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 17

of which Trump has adopted or adapted as his own—adduces several

key costs and dangers associated with US alliances.

First, America’s military alliances require Washington to defend

countries whose security is not vital to the United States. Second, US

alliances compel military expenditures far higher than would be necessary

simply to defend America itself. Third, maintaining the credibility of US

alliances forces America to adopt aggressive, forward-leaning defense

strategies. Fourth, having allies raises the risk of the United States

being entrapped in unwanted conicts. Fifth, America’s allies habitually

free ride on America’s own exertions. Sixth, alliances limit America’s

freedom of action and cause unending diplomatic headaches.

So how accurate are these critiques? We consider each in its turn.

In sum, America’s alliance system is hardly costless, and all of these

critiques contain at least a kernel of truth. In many cases, however, the

costs are signicantly exaggerated—or critics simply ignore that the

United States would have to pay similar costs even if it had no alliances.

Alliances require defending countries whose security is not vital to the United

States. The United States has formal security commitments to over thirty

treaty allies in Europe and the Asia-Pacic and informal or ambiguous

security commitments to over thirty additional countries.

These

commitments, particularly the formal treaty commitments, represent

something approaching a solemn vow to shed blood to defend non-

American lands. And some of the countries protected by US guarantees

are not, in and of themselves, critical to the global balance of power or

the physical security of the United States.

The United States could be

called upon to resist a Russian seizure of Estonia, and yet the American

people could survive and thrive in a world in which Estonia was occupied

by Russian forces.

Yet if this critique is not baseless, it is often overstated, because the

United States does have a vital interest in defending many of its current

allies. The basic geopolitical lesson of World Wars I and II—a lesson

many critics of US alliances endorse—is that Washington should not

allow any hostile power to dominate a crucial geopolitical region such as

Europe, East Asia, or the Middle East.

Accordingly, the United States

could still nd itself compelled to ght to defend those regions—and

7 For examples of these critiques, see Posen, Restraint; Christopher Layne, The Peace of Illusions:

American Grand Strategy from 1940 to the Present (Ithaca, NY: Cornell University Press, 2006); Stephen

M. Walt, Taming American Power: The Global Response to U.S. Primacy (New York: Norton, 2006);

Christopher A. Preble, The Power Problem: How American Military Dominance Makes Us Less Safe, Less

Prosperous, and Less Free (Ithaca, NY: Cornell University Press, 2009); Eric A. Nordlinger, Isolationism

Recongured: American Foreign Policy for a New Century (Princeton, NJ: Princeton University Press, 1995);

and Ted Galen Carpenter, A Search for Enemies: America’s Alliances after the Cold War (Washington,

DC: Cato Institute, 1992). Some of these works build on earlier (and often less critical) studies of

alliance dynamics, including Mancur Olson Jr. and Richard Zeckhauser, “An Economic Theory of

Alliances,” Review of Economics and Statistics 48, 3 (August 1996): 266–79, doi:10.2307/1927082; and

Glenn H. Snyder, Alliance Politics (Ithaca, NY: Cornell University Press, 1997).

8 See Adam Taylor, “Map: The U.S. Is Bound by Treaties to Defend a Quarter of Humanity,”

Washington Post, May 30, 2015. A precise count of US allies is difcult to achieve because the ac-

tual meaning and implications of certain US defense agreements—the Inter-American Treaty of

Reciprocal Assistance, for instance—are ambiguous.

9 It is important to note that all of America’s defense commitments provide an “out” through

clauses allowing Washington to act in accordance with its own constitutional processes. In essence,

treaties—although they are ratied by the Senate and carry the force of law—represent more of a

moral obligation than a tightly binding legal obligation to other states.

10 See John J. Mearsheimer and Stephen M. Walt, “The Case for Offshore Balancing: A Superior

U.S. Grand Strategy,” Foreign Affairs 95, 4 (July/August 2016): 70–83.

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47(2) Summer 2017

many key countries therein—even if formal alliance relationships did

not exist. This was, after all, precisely what happened during both world

wars and the Persian Gulf War, when American ofcials concluded

that US security required defending or liberating key countries in these

regions, even though Washington had not previously had military

alliances there. Alliances do not cause US entanglements overseas;

entanglements cause alliances.

US alliances compel military expenditures far higher than would be necessary

to defend America itself. To defend allies in the western Pacic or Europe,

the United States requires global power-projection capabilities and a

military that can win not just in its own backyard but in the backyards of

its great-power rivals. America thus needs a larger, more technologically

advanced, more sophisticated force than would be necessary strictly for

continental defense, along with an accompanying global-basing network.

For these reasons, the US military is indeed more expensive than it

would be absent US alliances. Yet this critique is also overblown. After

all, if the United States has an interest in preventing any hostile power

from dominating a key region of Eurasia, then alliances or no alliances,

Washington would still require a military capable of projecting decisive

power into these regions in an emergency.

Likewise, because America

has geopolitical objectives beyond the protection of allies—such as

counterterrorism and securing the global commons—the need for

advanced power projection capabilities and overseas bases would remain

even in a world without alliances.

Such a force might still be smaller than today’s military. If the

United States pursued a strategy in which it rolled back or attenuated

key alliances, one critic suggests, it could reduce defense spending to

2.5 percent of gross domestic product (GDP), as opposed to 3.5 or 4

percent.

Yet America would st ill have the world’s largest defense budget

by a considerable margin under this approach, and such a force—which

would consist, for instance, of only four carrier strike groups instead of

10 to 11 today—might not actually be sufcient to command the global

commons and ght its way back into key regions in a crisis.

In fact, if the United States pulled back from its alliance commitments

and waited for a crisis to develop before surging back into key regions,

it might nd such a mission more difcult—and more expensive—

than simply protecting its allies in the rst place. It was precisely this

fact—that the United States ended up deploying millions of troops to

liberate Western Europe and East Asia during World War II, at nancial

and human costs that would be almost unimaginable today, that led

American policymakers to adopt a different approach featuring formal

alliances and forward deployments thereafter.

Nor would eliminating

parts of the US basing network associated with protecting American

11 Evan Braden Montgomery, “Contested Primacy in the Western Pacic: China’s Rise and

the Future of U.S. Power Projection,” International Security 38, no. 4 (Spring 2014): 121, doi:10.1162

/ISEC_a_00160.

12 Posen, Restraint.

13 Hal Brands, The Limits of Offshore Balancing (Carlisle Barracks, PA: Strategic Studies Institute,

2015), 23–28.

14 See Robert J. Art, A Grand Strategy for America (Ithaca, NY: Cornell University Press, 2003),

205; and James R. Holmes and Toshi Yoshihara, “An Ocean Too Far: Offshore Balancing in the

Indian Ocean,” Asian Security 8, 1 (March 2012): 11, doi:10.1080/14799855.2011.652025.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 19

allies save much money absent corresponding force reductions, because

host-nation support arrangements often make it roughly as cheap, if not

cheaper, to station American forces overseas than to station them in the

United States.

American defense expenditures could slightly decrease

in a world without US military alliances, at least in the short-term, but

the savings would be less dramatic—and perhaps more ephemeral—

than one might expect.

Maintaining the credibility of American alliances requires adopting forward-

leaning defense strategies. This critique comes closer to the mark. Prior to

the Cold War, the US strategic posture was essentially one of allowing

aggressors to conquer friendly states in Europe and East Asia, and then

mobilizing to liberate those areas. Since the late 1940s, however, US

policymakers have worried that American allies will be unlikely to risk

aligning with Washington—and thereby antagonizing hostile neighbors

such as the Soviet Union—if they believe the United States will simply

allow them to be overrun in a conict. If being liberated rst requires

being conquered, who wants to be liberated?

Accordingly, since the early Cold War, the United States has focused

on defending rather than liberating allies. This strategy required

Washington to pledge to defend West Germany at the Rhine despite

the enormous difculty of doing so, to forward-station forces in

Europe and East Asia, and even to pledge rapid nuclear escalation to

defend vulnerable European allies.

Since the end of the Cold War, the

dilemmas associated with forward defense have been far less dangerous

and agonizing because the United States has not confronted a rival

superpower. But the return of great-power competition in recent years

has begun to raise these issues anew, albeit in less dramatic fashion. Part

of the rationale for the Pentagon’s much-hyped Air-Sea Battle concept

appears to be to cripple China’s power-projection capabilities before it

can subdue US allies in the Western Pacic.

The recent stationing of

US and NATO battalions in the Baltic states—in some cases, less than

200 miles from major Russian cities such as St. Petersburg—reects

similar imperatives.

Having allies raises the risk of entrapment. Critics of US alliances point to

the danger of “reckless driving” and “chain-ganging.” Reckless driving

occurs when an ally, protected by a US security guarantee, behaves more

provocatively than would otherwise be prudent. Reckless driving, in

turn, can trigger chain-ganging. If an ally intentionally or unintentionally

triggers conict with an adversary, a formal security commitment may

force the guarantor to enter the conict whether it desires to or not.

There is some irreducible danger of reckless driving and chain-ganging

in any credible alliance, of course. Yet historical evidence suggests that

this problem is actually less severe in US alliances than one might expect.

15 See Patrick Mills et al, The Costs of Commitment: Cost Analysis of Overseas Air Force Basing (work-

ing paper, RAND Corporation, Santa Monica, CA, April 2012).

16 On this dynamic, see Melvyn P. Lefer, A Preponderance of Power: National Security, The Truman

Administration, and the Cold War (Stanford, CA: Stanford University Press, 1992).

17 Marc Trachtenberg, A Constructed Peace: The Making of the European Settlement, 1945–1963

(Princeton, NJ: Princeton University Press, 1999).

18 On AirSea Battle (now called the Joint Concept for Access and Maneuver in the Global

Commons), see Andrew F. Krepinevich, Why AirSea Battle? (Washington, DC: Center for Strategic

and Budgetary Assessments, 2010).

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47(2) Summer 2017

As Michael Beckley and Victor Cha have shown, US policymakers

have long been sensitive to this dilemma, and have thus inserted

loopholes or escape hatches into security agreements with potentially

problematic partners, such as Syngman Rhee’s South Korea or Chiang

Kai-Shek’s Taiwan.

Today, for instance, the US security commitment

to Taiwan is ambiguous for this very purpose: to prevent Taipei from

assuming Washington will automatically rescue Taiwan if its leaders

provoke China. NATO forbids new members from having outstanding

territorial disputes for the same reason.

In recent decades, moreover, the United States has repeatedly

pressured allies and security partners to behave with restraint and

warned those allies against provoking stronger neighbors. American

ofcials underscored this point in dealings with Taiwan during the

George W. Bush administration, and reportedly, with the Philippines

and other allies in their more recent maritime disputes with China.

As a result, scholars have found few, if any, unambiguous cases over

the past 70 years in which the United States was dragged into shooting

wars solely because of alliance commitments.

Reckless driving and

chain-ganging are risks, but US ofcials have so far proven fairly adept

at managing them.

Allies habitually free ride. The opposite of reckless driving and chain

ganging is free-riding. Logically, because America is committed to

defend its allies, those states can spend less than they would otherwise

on their own defense. In 2011, for instance, the United States spent

around 4.5 percent of its GDP on defense, compared to 1.6 percent of

GDP for European NATO allies and roughly 1 percent for Japan.

To be fair, these statistics exaggerate the free-riding problem because

America’s defense budget includes higher-than-average personnel costs

as a way of recruiting and retaining an all-volunteer force in contrast to

many allies and partners whose labor markets enable them to recruit

personnel at lower wages or who rely primarily on conscription.

Moreover, this gap was subsequently narrowed as US military spending,

which had been inated by the Iraq and Afghanistan wars, fell after

2010. Yet free-riding is nonetheless real enough, as US ofcials have

frankly recognized. As Secretary of Defense Robert Gates told NATO

in 2011, “The blunt reality is that there will be dwindling appetite and

patience in the U.S. Congress—and in the American body politic writ

large—to expend increasingly precious funds on behalf of nations that

are apparently unwilling to devote the necessary resources or make

the necessary changes to be serious and capable partners in their own

defense.”

Indeed, this problem has troubling implications, for it renders

19 Michael Beckley, “The Myth of Entangling Alliances: Reassessing the Security Risks of

U.S. Defense Pacts,” International Security 39, 4 (Spring 2015): 7–48, doi:10.1162/ISEC_a_00197; and

Victor Cha, Powerplay: The Origins of the American Alliance System in Asia (Princeton, NJ: Princeton

University Press, 2016).

20 Thomas J. Christensen, The China Challenge: Shaping the Choices of a Rising Power (New York:

W. W. Norton, 2015), chapter 7. See also Ja Ian Chong and Todd R. Hall, “The Lessons of 1914 for

East Asia Today: Missing the Trees for the Forest,” International Security 39, 1 (Summer 2014): 23–24,

doi:10.1162/ISEC_a_00165.

21 Beckley, “Myth of Entangling Alliances.”

22 Posen, Restraint, 35–36.

23 Lindsay P. Cohn, “How Much is Enough?,” Strategic Studies Quarterly 9, no. 3 (Fall 2015): 47–61.

24 Thom Shanker and Steven Erlanger, “Blunt U.S. Warning Reveals Deep Strains in NATO,”

New York Times, June 10, 2011.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 21

the allies less capable of contributing to either out-of-area interventions

or collective defense operations.

If free-riding is indeed a dilemma, however, it is also an implicit

goal of US alliances, and it probably costs less—when “cost” is dened

holistically—than the likely alternatives. As extensive scholarship

demonstrates, a primary reason Washington created its postwar military

alliances was to break the cycle of unrestrained geopolitical competition

in Europe and East Asia, for fear such competition would give rise

to arms races and wars. Moreover, another prominent goal of US

alliances has been to restrain nuclear proliferation, for fear the spread

of nuclear weapons would make nuclear war more likely and dilute

American inuence.

In other words, some degree of free-riding is a feature of America’s

alliances, not a glitch. The United States has traditionally preferred

for allies to spend less on defense than they otherwise might, because

this restraint creates a world in which America itself is safer and more

inuential. To put it another way, does Washington really want a world in

which Germany and Japan both spend 5 percent of GDP on defense and

engage in nuclear arms-racing with adversaries? The answer is surely no,

even if US ofcials might still urge these countries to spend moderately

more than they do today.

Alliances limit America’s freedom of action and cause unending diplomatic

headaches. This is true enough. In international politics, it can be harder

to do things multilaterally than unilaterally. In many cases, relying on

allies means relying on less capable military forces to perform functions

the US military could better perform on its own, as Washington

discovered during the intervention in Kosovo in the late 1990s. Allies

bring their own idiosyncrasies into the relationship, often with messy

and frustrating results. A vivid example of this dynamic was the set

of caveats each NATO ally brought to the mission in Afghanistan—

restrictions on when, where, and how its forces could ght—ensuring

that, in terms of combat punch, the whole was somewhat less than the

sum of the parts.

Making alliances work also requires continual “gardening,” in the

phrase of George Shultz—continually massaging difcult relationships

and suffering insufferable allies such as Charles de Gaulle. As Jimmy

Carter once remarked, a meeting with allies represented “one of the

worst days of my diplomatic life.”

Yet there are obvious counterpoints

here: frustrations are inherent in any diplomatic relationship, the United

States undoubtedly nds it easier to address those frustrations within the

context of deeply institutionalized alliances, and any constraints on US

freedom of action have to be weighed against the myriad other ways in

which alliances enhance US exibility and power.

25 See Francis Gavin, “Strategies of Inhibition: U.S. Grand Strategy, the Nuclear Revolution, and

Nonproliferation” International Security 40, no. 1 (Summer 2015): 9–46, doi:10.1162/ISEC_a_00205;

and Stephen G. Brooks and William C. Wohlforth, America Abroad: The United States’ Global Role in the

21st Century (New York: Oxford University Press, 2016), 88–121.

26 Seth Jones, In the Graveyard of Empires: America’s War in Afghanistan (New York: W. W. Norton,

2009), 238–55.

27 Hal Brands, Making the Unipolar Moment: U.S. Foreign Policy and the Rise of the Post-Cold War Order

(Ithaca, NY: Cornell University Press, 2016), 24.

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47(2) Summer 2017

Overall, the costs and frustrations of US alliances are not illusory,

but many of those costs are actually less severe or salient than they

appear. The benets of US alliances, by contrast, are both more diverse

and more signicant than often appreciated.

Benets, Direct and Indirect

Just as critics overstate the costs of alliances, so they dramatically

understate the benets. The most direct and obvious advantages involve

the way allies allow the United States to punch above its own weight

by augmenting US military strengths across a range of issues and

contingencies. Yet alliances also offer additional geostrategic, political-

diplomatic, and economic advantages that enhance American power

and support a number of critical US national objectives. In other words,

America’s alliances are less entangling than empowering. By binding

itself to the defense of like-minded nations, the world’s sole superpower

makes itself all the more effective and inuential.

Military Punching Power

First and foremost, having allies signicantly increases the military

power the United States can bring to bear on a given battleeld. During

the Cold War, European forces were vital to maintaining something

approximating a balance of power vis-à-vis Warsaw Pact forces.

NATO

countries and other treaty allies also contributed to nearly every major

US combat operation of the postwar era, even though nearly all of those

operations occurred “out of area.” The United States may have waged

the Korean War in part to prove its willingness to defend its treaty allies

in Europe, but the NATO allies contributed over 20,000 troops—in

addition to other capabilities—to the ght.

Even during the Vietnam

War, treaty allies South Korea and Australia contributed substantial

ghting elements (and bore substantial casualties); South Korea sent

over 300,000 soldiers to Vietnam over the course of the conict and lost

over 4,500 in combat.

Virtually everywhere the United States fought

during the Cold War, it did so in the company of allies.

In the post-Cold War era, this benet has sometimes seemed less

important, because of the vast margin of US dominance vis-à-vis its rivals,

and because the gap between what Washington could do militarily and

what even its most capable allies could do militarily widened markedly.

Yet even so, the United States has relied heavily on allied participation

in nearly all of its major interventions.

During the Persian Gulf War, key NATO allies such as France and

the United Kingdom made large contributions to the coalition effort,

with the British providing 43,000 troops along with signicant air

and naval contingents. The NATO allies provided roughly half of the

60,000 troops who policed Bosnia as part of the Implementation Force

mission in that country from 1995 through 1996, and a majority of the

31,000 troops who made up the subsequent Stabilization Force. NATO

28 See Trachtenberg, A Constructed Peace; and Lefer, Preponderance of Power, 385–90.

29 The number may well have been higher; 20,000 seems like a rough and conservative estimate.

For general information, see Paul M. Edwards, United Nations Participants in the Korean War: The

Contributions of 45 Member Countries (Jefferson, NC: McFarland & Company, 2013).

30 James Sterngold, “South Korea’s Vietnam Veterans Begin to Be Heard,” New York Times,

May 10, 1992.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 23

contributions to the US-led war in Afghanistan peaked at around 40,000

troops; this contingent helped sustain the mission at a time of heavy

US focus on Iraq and made it possible for Washington to surge 30,000

additional troops into Iraq when its forces were strained to the limit.

Other US wars—in Iraq, Libya, and against the Islamic State—have

also featured noteworthy contributions from treaty allies in Europe and

the Asia-Pacic region. Both critics and defenders of US alliances often

speak of the frustrations of unequal burden sharing. But America’s

military burdens would be much higher if it did not have allies willing

to share them.

Having formal allies as opposed to relying on ad hoc partnerships

also yields a second and related military benet: it eases the process of

mobilizing cobelligerents for action in a crisis. It is possible to assemble

military coalitions on the y, of course, and every coalition military

venture in which the United States participated prior to 1945 was in

some sense improvised. Moreover, even in the post-World War II era,

the United States has solicited ad hoc contributions from nonallied

partner states. It is even possible, as the United States has repeatedly

demonstrated, to make a purely transactional alliance of convenience

with a “devil”—a country that otherwise shares very few interests

with America, such as the Soviet Union in World War II or Syria in the

Persian Gulf War.

The possibility of improvising military cooperation when needed

has led some critics to argue the United States can do away with formal,

institutionalized alliances altogether.

But turning every military

operation into the equivalent of pickup basketball greatly increases the

difculty of building an effective combined force. Pushing the analogy

further, pickup basketball is very hard to arrange in the absence of long-

standing arrangements and customs that increase the predictability of the

other actors. Economists refer to these difculties as transaction costs;

the routines and institutionalization of formal alliances make it much

easier to bring military power to bear at much lower transaction costs.

In formal alliances, the partners practice together in peacetime,

develop interoperability, and may even develop common equipment, thus

easing logistics challenges. They also establish diplomatic forums and

longstanding, fairly predictable relationships, thereby making it easier to

coordinate interests and achieve the political consensus necessary to use

force in the rst place.

To be sure, everything could be negotiated on

the y, but the price America would pay for this exibility would be the

31 See Hal Brands, Dealing with Allies in Decline: Alliance Management and U.S. Strategy in an Era of

Global Power Shifts (Washington, D.C.: Center for Strategic and Budgetary Assessments, 2017), 9–10;

Spencer C. Tucker and Priscilla Mary Roberts, eds., The Encyclopedia of Middle East Wars: The United

States in the Persian Gulf, Afghanistan, and Iraq Conicts (Santa Barbara, CA: ABC-CLIO, 2010), 214;

“Peace Support Operations in Bosnia and Herzegovina,” NATO, September 7, 2015, www.nato.int

/cps/en/natolive/topics_52122.htm; and Jones, Graveyard of Empires, 243–45.

32 Benjamin Schwarz and Christopher Layne, “A New Grand Strategy,” Atlantic, January 2002,

https://www.theatlantic.com/magazine/archive/2002/01/a-new-grand-strategy/376471/.

33 Both the advantages and limits of these practices are discussed in David P. Auerswald and

Stephen M. Saideman, NATO in Afghanistan: Fighting Together, Fighting Alone (Princeton, NJ: Princeton

University Press, 2014). Seth Johnston argues that institutionalization also facilitates NATO’s adap-

tion and innovation, keeping NATO relevant and useful long after its original purpose had been

eclipsed. Seth A. Johnston, How NATO Adapts: Strategy and Organization in the Atlantic Alliance since

1950 (Baltimore, MD: Johns Hopkins University Press, 2017).

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47(2) Summer 2017

signicantly greater difculty—and, most likely, the signicantly longer

timelines—of piecing together a coalition in a crisis.

A third major military contribution of allies is the specialized

capability they can bring to the table. Sometimes this is material

capability: British, French, and Australian special operations forces have

all made vital contributions to the Global War on Terror. The Japanese

have some of the nest antisubmarine warfare capabilities in the world,

which would be essential in a US conict with China.

More often US

allies contribute geographical capability in the form of proximity to the

theater of interest. This proximity allows forward staging of the strike

and intelligence assets, particularly air assets, on which the American

way of war depends. It also allows for specialized technical intelligence

collection that would be nearly impossible to conduct without local

partners. The counter-ISIS campaign, for instance, would have been

vastly more difcult had the United States not had access to key facilities

controlled by either treaty allies (Turkey) or long-standing military

partners (Qatar or Bahrain).

Similarly, the United States would face

a nearly impossible task in any North Korean contingency without the

extensive US basing network in Japan.

And, of course, the United States has also traditionally relied on

another allied contribution: intellectual capability. By virtue of their

history, US allies have unique networks of relationships, along with the

distinctive insights those relationships afford, in many regions of interest.

This translates into intelligence—particularly human intelligence—that

would be almost impossible for America to generate on its own; consider,

for instance, the intelligence advantages possessed by the French in

northwest Africa or the Italians in Libya.

The existence of formal, deeply institutionalized alliances, in

turn, facilitates the sharing of such intelligence. Three out of the four

countries that make up the Five Eyes intelligence partnership with the

United States are longstanding treaty allies; Washington also cooperates

extensively with its NATO allies on intelligence matters.

In this as in

other respects, America’s alliances make it far stronger and more capable

militarily than it would otherwise be.

Geostrategic Inuence and Global Stability

If alliances are thus helpful in terms of the conicts America wages,

they are more helpful still in terms of the conicts they prevent and

the broader geostrategic inuence they confer. Indeed, although the

ultimate test of America’s alliances lies in their efcacy as warghting

34 See, for instance, “The Japanese Military’s Focus on Anti-Submarine Capabilities,” Stratfor

Worldview, June 24, 2013, https://worldview.stratfor.com/analysis/japanese-militarys-focus-anti

-submarine-abilities.

35 American ofcials described access to Incirlik, Turkey, as a “game changer” in the counter-

ISIS campaign. Ceylan Yeginsu and Helene Cooper “U.S. Jets to Use Turkish Bases in War on ISIS,”

New York Times, July 23, 2015.

36 On local and regional advantages, see, for instance, Christopher S. Chivvis, The French War on

Al Qa’ida in Africa (Cambridge: Cambridge University Press, 2015).

37 See Sir Stephen Lander, “International Intelligence Cooperation: An Inside Perspective,”

Cambridge Review of International Affairs 17, 3 (October 2004): 481–93, doi:10.1080/0955757042000

296964; and Richard J. Aldrich, “U.S.-European Intelligence Co-Operation on Counter-Terrorism:

Low Politics and Compulsion,” British Journal of Politics and International Relations 11, 1 (February

2009): 122–39, doi:10.1111/j.1467-856x.2008.00353.x.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 25

coalitions, the most powerful benets they provide come in the normal

course of peacetime geostrategic management and competition.

First, US alliances bind many of the richest and most militarily capable

countries in the world to Washington through enduring relationships of

deep cooperation. Alliances reect shared interests rather than creating

them, of course, and the United States would presumably have close ties

to countries such as the United Kingdom even without formal alliances.

But alliances nonetheless serve as “hoops of steel.” They help create

a sense of permanence and shared purpose in key relationships; they

provide forums for regular interaction and cooperation; they conduce to

deeply institutionalized exchanges (of intelligence, personnel, and other

assets) that insulate and perpetuate friendly associations even when

political leaders clash.

And insofar as US alliances serve these purposes

with respect to immensely inuential countries in Europe and the

Asia-Pacic, they help Washington preserve a signicant overbalance of

power vis-à-vis any competitor.

Second, alliances have a strong deterrent effect on would-be

aggressors. American alliances lay down “redlines” regarding areas

in which territorial aggression is impermissible; they complicate the

calculus of any potential aggressor by raising the strong possibility that

an attack on a US ally will mean a ght with the world’s most formidable

military. The proposition that “defensive alliances deter the initiation of

disputes” is, in fact, supported by empirical evidence, and the forward

deployment of troops strengthens this deterrence further still.

NATO clearly had an important deterrent effect on Soviet

calculations during the Cold War, for instance; more recently, Russia

has behaved most aggressively toward countries lacking US alliance

guarantees (Georgia and Ukraine), rather than toward those countries

possessing them (the Baltic states or Poland). In other words, alliances

make the geostrategic status quo—which is enormously favorable to the

United States—far “stickier” than it might otherwise be.

Third, and related to this second benet, alliances tamp down

international instability more broadly. American security guarantees

allow US allies to underbuild their own militaries; while always annoying

and problematic when taken to extremes, this phenomenon also helps

avert the arms races and febrile security competitions that plagued

Europe and East Asia in earlier eras. In fact, US alliances are as useful

in managing tensions among America’s allies as they are in constraining

America’s adversaries.

NATO was always intended to keep the “Americans in” and the

“Germans down” as well as the “Russians out”; US presence, along

with the creation of a framework in which France and Germany were

38 On deep institutionalization, see Celeste A. Wallander, “Institutional Assets and Adaptability:

NATO after the Cold War,” International Organization 54, 5 (Autumn 2000): 705–35; and Aldrich,

“U.S.-European Intelligence Co-Operation.”

39 Jesse C. Johnson and Brett Ashley Leeds, “Defense Pacts: A Prescription for Peace?,” Foreign

Policy Analysis 7, 1 (January 2011): 45–65, esp. 45, doi:10.1111/j.1743-8594.2010.00122.x; Brett

Ashley Leeds, “Do Alliances Deter Aggression? The Inuence of Military Alliances on the Initiation

of Militarized Interstate Disputes,” American Journal of Political Science 47, 3 (July 2003): 427–39,

doi:10.2307/3186107; Paul K. Huth, “Extended Deterrence and the Outbreak of War,” American

Political Science Review 82, 2 (June 1988): 423–43, doi:10.2307/1957394; and Vesna Danilovic, “The

Sources of Threat Credibility in Extended Deterrence,” Journal of Conict Resolution 45, 3 (2001):

341–69, doi:10.1177/0022002701045003005.

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47(2) Summer 2017

incentivized to cooperate rather than compete with one another, would

help stie any resurgence of tensions between these historical rivals.

Similarly, US alliance guarantees in the Asia-Pacic were designed, in

part, to create a climate of security in which Japan could be revived

economically without threatening its neighbors, just as the expansion

of NATO after the Cold War helped prevent incipient rivalries and

territorial irredentism among former members of the Warsaw Pact.

US alliances keep things quiet in regions Washington cannot ignore,

thereby fostering a climate of peace in which America and its partners

can ourish.

Fourth, US alliances impede dangerous geostrategic phenomena

such as nuclear proliferation. As scholars such as Francis Gavin have

emphasized, US security guarantees and forward deployments have

played a critical role in convincing historically insecure, technologically

advanced countries—Germany, Japan, Taiwan, South Korea, among

others—to forego possession of the world’s absolute weapon. In several

of these cases, moreover, the United States has used the security leverage

provided by alliance guarantees to dissuade allies from pursuing the

bomb after they had given indications of their intent to start down that

path.

If, as seems likely, a world with more nuclear powers is likely to

be a more dangerous world in which crises more frequently take on a

nuclear dimension and the risk of nuclear conict is higher, then the

value of American alliances looms large indeed.

In sum, as the framers of the post-World War II order understood,

phenomena such as massive instability, arms racing, and violence in key

regions would eventually imperil the United States itself.

Whatever

modest reduction in short-term costs might come from pursuing a “free

hand” or isolationist strategy was thus more than lost by the expense

of ghting and winning a major war to restore order. Accordingly,

America’s peacetime alliance system represents a cheaper, more prudent

alternative for maximizing US inuence while also preventing raging

instability by deterring aggression and managing rivalries among friends.

The fact that so many observers seem to have forgotten why, precisely,

America has alliances in the rst place is an ironic testament to just how

well the system has succeeded.

Political Legitimacy and Consultation

Beyond their military and geostrategic virtues, alliances provide

important political benets that facilitate the use of American power

both internationally and with respect to the domestic audience. The chief

political advantage of alliances is enhanced international legitimacy.

40 See Trachtenberg, A Constructed Peace; also Timothy P. Ireland, Creating the Entangling Alliance:

The Origins of the North Atlantic Treaty Organization (Westport, CT: Greenwood Press, 1981).

41 The role of NATO’s persistence and expansion in stiing security competition in Europe is,

ironically, acknowledged by one of the alliance’s foremost academic critics. See John J. Mearsheimer,

“Why Is Europe Peaceful Today?,” European Consortium for Political Research Keynote Lecture,

European Political Science 9, 3 (September 2010): 388, doi:10.1057/eps.2010.24.

42 See Gavin, “Strategies of Inhibition”; Gene Gerzhoy, “Alliance Coercion and Nuclear

Restraint: How the United States Thwarted West Germany’s Nuclear Ambitions,” International Security

39, no. 4 (Spring 2015): 91–129, doi:10.1162/ISEC_a_00198; and Mark Kramer, “Neorealism,

Nuclear Proliferation, and East-Central European Strategies,” in Unipolar Politics: Realism and State

Strategies after the Cold War, ed. Ethan B. Kapstein and Michael Mastanduno (New York: Columbia

University Press, 1999), 385–463.

43 Lefer, Preponderance of Power.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 27

Formal alliances and the partnership of allies—particularly democratic

allies—in cooperative ventures confer the perceived legitimacy of

multilateral action. This perception is especially important when

an administration is unable to secure the formal legitimacy of a UN

Security Council Resolution authorizing the use of force. In the case

of the Kosovo conict, for example, being able to conduct the mission

under NATO auspices somewhat mitigated charges of “American

unilateralism.”

Similarly, the ability of the United States to muster a

coalition of the willing involving both NATO and Asia-Pacic allies

in the Iraq War provided some rebuttal to critics who declaimed the

invasion as a “unilateral” endeavor.

Allied support also enhances the perceived legitimacy of the actions

for domestic audiences, thus strengthening the political foundations for

military ventures.

The willingness of other states to participate in a

military intervention can signal that the resort to force is a wise and

necessary move, has reasonable prospects for success, and will enjoy

some minimal moral legitimacy. All of these factors can shore up public

support and give the intervention greater political resilience should it

prove more difcult than expected, and this international cooperation

is easier to achieve in the framework of longstanding military alliances.

Finally, allies provide useful input on use of force decisions.

Particularly when the deliberations involve long-standing treaty allies,

US ofcials can have more honest discussions about difcult policy

choices because the participants are “all in the family.” Put another

way, every US president reserves the right to use force unilaterally when

American interests demand. Yet as presidents have generally understood,

the failure to persuade other partners to approve and to join America

in the effort is itself a powerful cautionary warning.

The need to make

persuasive arguments to allies and partners is a useful disciplining device

to prevent policy from running off the rails.

Diplomatic Leverage and Cooperation

Beyond their military, geostrategic, and political impact, having

formal military alliances greatly increases the diplomatic leverage US

leaders can bring to bear on thorny international challenges. Formal

alliances and long-standing partnerships give US leaders myriad fora

in which to raise concerns and advocate favored courses of action.

Europeans are obliged to listen to the United States on European issues

because Washington’s leading role in NATO makes it the central player

in European defense; the same dynamic prevails vis-à-vis US allies in

the Asia-Pacic. To give just one concrete example, the United States has

repeatedly prevented the European Union from lifting its arms embargo

on China because of the security leverage it has through NATO.

44 For an argument stressing the reliance on alternative sources of legitimacy during the

Kosovo crisis, see Robert Kagan, “America’s Crisis of Legitimacy,” Foreign Affairs 83, 2 (March/

April 2004): 74–77.

45 Joseph M. Grieco et al., “Let’s Get a Second Opinion: International Institutions and

American Public Support for War,” International Studies Quarterly 55, no. 2 (June 2011): 563–83,

doi:10.1111/j.1468-2478.2011.00660.x.

46 For instance, the Bush Administration was stymied on the Sudan by the reluctance of the

rest of the international community to intervene. Condoleeza Rice, No Higher Honor: A Memoir of

My Years in Washington (New York: Crown Publishers, 2011), 582–85.

47 See Glenn Kessler, “Rice Warns Europe Not to Sell Advanced Weaponry to China,”

Washington Post, March 21, 2005.

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47(2) Summer 2017

Having allies also increases US diplomatic options vis-à-vis

adversaries. Here, the danger of entrapment (getting drawn into conicts

America might otherwise have avoided) must be weighed against

the benets of having more options in dealing with the adversaries

Washington cannot ignore. One such benet is the increased range

of signaling options available to strategists during an unfolding crisis.

Consider US efforts to constrain the North Korean nuclear program.

Without military alliances with South Korea and Japan, the United States

would have only two baskets of military options short of actual resort to

force in order to signal resolve and to shape North Korean calculations:

either taking relatively meaningless actions, such as changing the alert

levels in the homeland or in other theaters, or taking relatively dramatic

escalations, such as moving an aircraft carrier battle group within range

of the Korean peninsula or ying sorties close to the North Korean

border. With South Korea and Japan as allies, however, Washington

has a wider variety of midrange actions—increasing missile defense

capability or readiness in theater, raising local alert levels, and so on.

These steps give leaders ways of responding, and thereby inuencing

diplomatic negotiations, while also better positioning America to

respond if diplomacy fails.

Finally, alliances enhance US diplomatic efforts on security issues

beyond those directly related to collective defense. The United States

has used its alliances as vehicles for cooperation on counterterrorism

(both prior to and since September 11, 2001), as well as for countering

cybercrime, proliferation, and piracy; addressing climate change; and

responding to other challenges. All of these efforts involve substantial

intelligence sharing, information pooling, and coordination across law

enforcement and other lines of action. And all of this coordination

is greatly facilitated when conducted through deeply institutionalized

alliances and long-standing cooperative relationships.

The United States has, of course, also been able to achieve tactical

cooperation even from long-standing adversaries on issues such as

counterterrorism, but such cooperation is frequently less signicant,

harder to obtain, and comes at a higher price in terms of the reciprocal

American “gives” required in transactional relationships. It is thus with

good reason that, when an international crisis breaks or a new global

challenge emerges, the rst phone calls made by US leaders are usually

to America’s closest allies.

Economic Benets

As noted, the economic costs of US alliance commitments are lower

than conventionally assumed because the alliances allow Washington to

project military power much more cheaply than otherwise would be the

case. Alliances also generate numerous indirect economic benets—so

many that they may constitute a net prot center for the United States.

As a recent analysis of the deployment of US troops abroad and of US

treaty obligations shows, both of these forms of security commitments

48 See, for example, the US-South Korean incremental tit-for-tat response to recent North

Korean military provocations, Dan Lamothe, “U.S. Army and South Korean Military Respond to

North Korea’s Launch with Missile Exercise,” Washington Post, July 4, 2017.

49 Art, Grand Strategy, 201–2.

Reevaluating Diplomatic & militaRy poweR Brands and Feaver 29

are correlated with several key economic indicators, including US

bilateral trade and global bilateral trade.

The more US troops are

deployed to a given country, the greater US bilateral trade is with the

country in question. Furthermore, the effect extends to non-US global

bilateral trade: “Countries with U.S. security commitments conduct

more trade with one another than they would otherwise.” Adding all

the economic costs and benets of these treaty commitments together

produces the estimate that the alliances offer more than three times as

much gain as they cost.

American alliance commitments advance US economic interests in

other ways, as well. For decades, US diplomats and trade negotiators

have used the security leverage provided by alliance commitments

to extract more favorable terms in bilateral nancial and commercial

arrangements. During the Cold War, West Germany made “offset”

payments to the United States—transfers to shore up the sagging US

balance of payments—as a means of preserving the American troop

presence in Europe.

More recently, American negotiators obtained more favorable

terms in the South Korea-United States trade agreement than the

European Union did in a parallel agreement with Seoul. “Failure would

look like a setback to the political and security relationship,” one US

ofcial noted; this dynamic gave Washington additional negotiating

leverage.”

Additionally, as other scholars have shown, the US willingness

to defend other states and police the global commons reinforces the

willingness of other countries to accept a global order which includes

favorable economic privileges for the United States, such as the dollar

as the primary global reserve currency.

And, of course, by sustaining a

climate of overall geopolitical stability in which trade and free enterprise

can ourish, alliances bolster American and global prosperity in broader

ways, as well.

Conclusion

The balance sheet on America’s alliances, then, is really not much

of a balance at all. There are costs and dangers associated with US

alliances, and some of these are real enough. But many of those costs

and dangers are exaggerated, blown out of proportion, or rest on a

simple misunderstanding of what the United States would have to do in

the world even if it terminated every one of its alliances. The benets of

US alliances, conversely, are far more diverse and substantial than critics

tend to acknowledge. In sum, any grand strategy premised on putting

America rst should recognize that by creating and sustaining its global

alliance network, America has indeed put itself rst for generations.

50 Daniel Egel and Howard Shatz, “Economic Benets of U.S. Overseas Security Commitments

Appear to Outweigh Costs,” The RAND Blog, September 23, 2016, http://www.rand.org

/blog/2016/09/economic-benets-of-us-overseas-security-commitments.html.

51 Francis J. Gavin, Gold, Dollars, and Power: The Politics of International Monetary Relations, 1958–

1971 (Chapel Hill: University of North Carolina Press, 2004).

52 Stephen G. Brooks, G. John Ikenberry, and William C. Wohlforth, “Don’t Come Home,

America: The Case against Retrenchment,” International Security 37, 3 (Winter 2012/13): 44.

53 G. John Ikenberry, Liberal Leviathan: The Origins, Crisis, and Transformation of the American World

Order (Princeton, NJ: Princeton University Press, 2012).

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47(2) Summer 2017

If this is the case, then why have alliances proven to be such

lightning rods for both academic and presidential criticism of late?

Part of the answer lies in the dynamic noted at the outset of this piece.

The dangers and risks inherent in US alliances are mostly obvious and

intuitive, whereas the benets are often subtler, more indirect, or require

digging deeper into the underlying logic of American internationalism

to understand. Those benets, moreover, often reside in things that do

not happen—and are thus harder to observe, let alone measure. Yet part

of the answer also undoubtedly lies in the fact that American alliances,

like so much of American foreign policy today, appear to be in danger of

becoming a victim of their own success. The fact that US alliances have

been so effective, for so long, in maximizing US inuence and creating

an advantageous international environment has made it all too easy to

take their benets for granted. It would be a sad irony if the United

States turned away from its alliances, only then to realize just how much

it had squandered.

American alliances do not function perfectly, of course, and today

as at virtually every point since the late 1940s, there are challenges on

the horizon: the relative decline of many key US allies vis-à-vis US

adversaries, the difculties of prodding partners in Europe and Asia

to do more on defense, the threat posed by coercion and intimidation

meant to change the geopolitical status quo without triggering alliance

redlines. Likewise, reasonable observers can debate what military strategy

the United States should pursue for upholding its alliance commitments

in the Baltic or the western Pacic. But the vexations of addressing

these challenges within the framework of America’s existing alliances

are undoubtedly less than the costs and perils to which the United States

would be exposed without its alliances. Winston Churchill had it right

when he said, “There is only one thing worse than ghting with allies,

and that is ghting without them.” The US policy community would do

well to heed this admonition today.

Hal Brands

Dr. Hal Brands is the Henry A. Kissinger Distinguished Professor of Global

Affairs at the Johns Hopkins School of Advanced International Studies and a

Senior Fellow at the Center for Strategic and Budgetary Assessments.

Peter D. Feaver

Dr. Peter D. Feaver, a professor of political science and public policy at Duke

University, directs the Triangle Institute for Security Studies and the Duke

Program in American Grand Strategy.