2

DEFENSE AND DETERRENCE IN THE COLD WAR

As the Cold War set in, US policymakers recognized that competition with the Soviet Union was a geopolitical reality. Those same policymakers hoped to prevent conflict through international institutions and laws, but they knew that the United Nations alone could not protect all of the nation’s vital interests. If the United States failed to defend essential military-industrial powers in Eurasia—including defeated ones that might rise again—it could find itself an isolated bunker-nation. Thus alliances were layered on top of the new postwar institutions. The United States ringed Europe and Asia with security guarantees to contain Soviet influence.

The decision to form a far-flung network of alliances with small, war-ravaged states was not altogether intuitive. If one seeks to protect oneself, why not partner with the strongest possible allies? But early Cold War planners realized there were good reasons to ally with the specific weak states they chose. Most important was geography. In exchange for its security guarantee, the United States would gain access to bases ideally located for the purposes of forward defense and deterrence and would gain political relationships that made its guarantee credible. And because weak allies were dependent on US protection, the United States garnered influence over their leaders—leverage that it could use to stabilize and preserve its alliances.

This system came at some cost. In particular the United States had to reassure allies it was truly committed, necessitating considerable outlays in US troops and money. Washington also had to supervise the recoveries of Germany and Japan, to prove to other allies that these once-aggressive powers could be trusted as members of the US-backed network.

As Lord Hastings Ismay, the first secretary general of NATO, summarized, the alliance system was designed to “keep the Americans in, the Russians out, and the Germans down.”¹ The network had to give the United States the forward bases and political ties it needed to hold off Soviet aggression, while reassuring allies that the United States would keep them safe.

Insofar as it can be measured, America’s alliance gamble appears to have paid off, largely delivering on planners’ objectives. With the strategy of forward defense and deterrence in place, no alliance members were ever attacked. Washington kept its allies in check, so that they did not threaten the system. And by keeping the allies’ worst impulses at bay, the United States managed to avoid entanglement in faraway wars.

Why Did America Ally?

States often form alliances to balance against an adversary, offsetting its economic and military power and counteracting its threats. By pooling resources, allies defend against a rival who might otherwise be able to defeat them individually.² Thus in the late nineteenth and early twentieth centuries, for example, European powers generally chose to align with other strong states, in hopes of matching the warfighting capabilities of their competitors through defense collaboration.

The United States applied a very different logic in the early Cold War. The allies it selected had largely been decimated in conflict just a few years earlier. They were vulnerable to Soviet pressure and did not add much to America’s military strength. It is tempting, therefore, to believe that the United States was providing a service on behalf of those in need. Those who excoriate Washington for spending on defense commitments to countries that cannot reciprocate seem to believe precisely that. But US leaders did not choose this alliance structure for altruistic reasons. Unlike European leaders of the preWorld War I era, they saw alliance asymmetry as advantageous.

Declassified documents from the early Cold War period reveal why US strategists made the choices they did: because they wanted to site bases far from the homeland. These would allow rapid response in case conflict broke out and would put the frontlines in Europe and Asia, not California or New York. Distant bases also heightened the deterrent effect of American power by demonstrating that the United States had the capability to fight far from home and the will to do so. The United States did not need fully reciprocal guarantees. Instead it needed geographically advantageous states on its side, so that it could defend and deter while exerting control over them, thereby ensuring its own survival.

Forward for Defense

Defensive alliances allow partners to make war preparations together by pooling their resources.³ But allies can be useful apart from their military and economic might. An ally also can be geographically beneficial, particularly if it is proximate to potential adversaries. A major power might acquire bases on the ally’s soil, improving its own defensive footing and impeding an adversary from attacking closer to home. This is known as forward defense.

This was a leading logic of the Cold War system. After a devastating world war, America’s partners did not have much firepower, but they formed a perimeter around the Soviet adversary where the United States could site troops, naval vessels, aircraft, and other equipment. In exchange for basing rights, which require host states to cede some of their sovereignty, the United States promised security.⁴

Forward defense mitigated the vulnerabilities major powers felt after the advent of long-range air power, missiles, and nuclear weapons. But those weapons were also vital to the operation of a forward-defense effort. The United States could use its own nuclear and long range–strike capabilities to guard faraway allies. This marked a turning point in the logic of defense. Historically defense had largely been a tactical and operational problem of protecting borders. Modern military technology accelerated the capacity to deliver enormous destruction, so that defense became a strategic problem. Now the question was how the United States could keep its homeland safe when nuclear warheads and, soon, long-range missiles could arrive with only minutes’ notice. The protection of the homeland and of allies could no longer be responsive, ceding initiative to the adversary: it required advanced preparation and positioning. Forward presence was the solution to this strategic problem, allowing the defender to maintain abroad the capabilities it needed to deny the adversary a quick victory if war erupted.⁵

Forward presence has other benefits, too. By working on the ground with its allies’ governments and armed forces, the major power can help its allies build up their own capabilities and plan for potential conflict scenarios. And overseas troops can provide planners at home better intelligence on foreign threats.⁶

Military planners began studying postwar basing options as early as 1943, but America’s postwar defense strategy did not crystallize until the early Cold War, when the Soviet Union emerged as the primary foe. Only then did it become clear that many US bases belonged in Europe. By 1947 the Joint Chiefs of Staff considered the need for bases in Europe to be urgent, and they encouraged the Truman administration to secure long-term basing rights.⁷ Absent an American military presence, senior US officials argued, Europe would collapse in the event of a Soviet attack.⁸ By 1948 American officials agreed that the Soviet Union was willing to use force to further its objectives, necessitating a US-led alliance based in Europe to resist.⁹

For the architects of the Atlantic alliance, the potential of one or another partner depended in part on the degree to which it would aid in forward defense. George Kennan evaluated prospective NATO members on the basis of the military value they could provide. Other officials considered which Western European countries would be most likely to grant advantageous base access.¹⁰ This planning did not immediately come to fruition—only after the Korean War demonstrated clearly the value of forward defense did NATO establish its integrated military structure and the United States drastically increase its troop commitment in Europe. The sudden and calamitous invasion on the Korean Peninsula was evidence that the defensive logic of the Atlantic alliance needed to be implemented more fully.

In Asia, too, US alliances were driven by a forward-defense logic, centered on the so-called First Island Chain. American strategists identified as geographically advantageous the line of islands and archipelagos descending from the Aleutians, through Japan, and to the Philippines. This stretch would, strategists believed, serve as a defensive perimeter.¹¹ Kennan argued that the United States should adopt a maritime strategy against the Soviet Union, emphasizing control of the island chain and sea lanes to secure the Pacific, and General Douglas MacArthur announced the strategy publicly in 1949.¹² In 1951 Dulles, then a Truman administration consultant, argued that the First Island Chain, extending as far south as Oceania, should be the country’s primary defensive priority. Every friendly country in that chain was a potential ally in Dulles’s view. His advocacy nudged the Truman team toward extending alliances to Australia and New Zealand and Eisenhower to ally with Korea and Taiwan.¹³

Each component in the chain had a role to play. As early as 1945, US officials recognized that the Philippines was appropriate for forward basing. The country faced few external threats, and its geographic position made it strategically propitious.¹⁴ Japan also was deemed a geographic jewel, useful for defense against Soviet sea power. From bases in Japan, the US Navy could hem in the Soviet Navy in the Pacific, or so the thinking went.¹⁵ As American leaders prepared to sign a peace treaty with Japan, trading occupation for alliance, civilian and military brass argued that continued control of Okinawa and the Ryukyu Island Chain was crucial for US naval power projection. Japan was only more valuable after the outbreak of the Korean War and the intensification of the Chinese Civil War, emerging as the hub for US operations in the Pacific.¹⁶

Over the course of the Korean War, the South, too, emerged as a strategic location. In the early years of the war, the Truman administration was no more eager to extend a formal defense treaty to the mercurial Syngman Rhee than it had been when it omitted South Korea from its defense perimeter in 1950. As the war dragged on, however, the administration focused on the benefits the South could provide in containing threats.¹⁷ When Eisenhower took office, his team also looked to Korea as a possible land anchor of the First Island Chain that would help the United States hold the line against the Soviet Union and its proxies.¹⁸ This dovetailed with President Rhee’s demand that the United States promise the South protection in exchange for alliance. Eisenhower wanted the war over but was happy to comply: he agreed that 50,000 American troops belonged in South Korea for the long term. A US outpost in the South could prevent another communist fait accompli. If instead the United States decamped, as it had in 1949, communist forces might eventually gain a foothold in the South, making it impossible to defend South Korea and difficult to protect Japan.¹⁹

Taiwan too became an ally in part because of its value in forward defense. In the late 1940s, American strategists hoped that China would be unified under the control of Chiang Kai-Shek and would serve as a regional counterweight to the Soviet Union. Instead the Chinese Civil War left the mainland under communist control and aligned with Moscow. American planners flirted with the idea of intervening to seize Taiwan as an American base but decided the move was too risky.²⁰ The matter then lay dormant until the Korean War broke out, after which US strategists again began to advocate for forward deployment on the island. The Republic of China had the second-most capable noncommunist military in Asia, after South Korea’s, and Taiwan’s location just a hundred miles from the Chinese coast made it a useful foothold. Furthermore, strategists reasoned that if Taiwan were to fall into communist hands, it would become much more difficult to defend Japan, the Philippines, and even Australia. Taiwan was an indispensable link in the First Island Chain.²¹

In Europe and Asia, the United States intended to hold the balance of power by using alliances for forward defense. But the goal was not simply to have troops and equipment well positioned if fighting should break out. Forward basing also fulfilled a second goal of the alliance system: extended deterrence.

Allying to Deter

When a state practices deterrence, it aims to prevent another from taking an unwanted action by altering the way it evaluates that action’s costs. At its most ambitious, deterrence seeks to prevent wars from breaking out when they might otherwise. This was the task that the United States arrogated to itself after the Second World War. As Bernard Brodie asserted in 1946, “Thus far the chief purpose of our military establishment has been to win wars. From now on its chief purpose must be to avert them. It can have almost no other useful purpose.”²²

Deterrence strategies come in two basic forms. A strategy of deterrence by denial aims to demonstrate to an adversary that it will not achieve its goals if it attacks. Deterrence by punishment seeks to convince an adversary that if it attacks, it will suffer devastating retaliation. Put differently, denial demonstrates that the defender has the capabilities it needs to prevail in a specific war, while punishment communicates that the prospective war will be too costly for the attacker to bear.²³

When a state practices deterrence on its own behalf, it sends signals that an adversary should not attack its homeland. But alliances can help a state to project deterrence, taking deterrence by punishment and denial beyond its borders. When a state aims to dissuade attacks on distant allies it is practicing extended deterrence.²⁴ By making targeted threats and demonstrating its capacity to secure its allies, a state can deter wars that might otherwise have involved them. If deterrence is successful, those wars will never erupt.

Achieving extended deterrence is much more difficult than establishing deterrence on behalf of one’s own country. If an adversary threatened the West Coast of the United States, and American leaders responded by promising devastating punishment in return, no one would doubt their sincerity. Extended deterrence, however, requires the defender to promise that it will treat an attack on a foreign country as an attack on its own, obligating it to assume great cost and risk on behalf of others’ immediate security.²⁵ Such a promise is inherently less credible than a promise to defend one’s own territory and sovereignty.

Extended-deterrence guarantees become all the more tenuous if an adversary has the ability to retaliate against the defender. Say the United States promises to protect France from the Soviet Union, which lacks missiles that can reach the United States. In this case the United States will not face direct retaliation if it enters a conflict on behalf of the French ally, so the defensive promise is relatively easy to keep and its deterrent power is accordingly high. If, however, the Soviet Union can strike the US homeland, then by pledging to defend France, American leaders are accepting the possibility that their country will be struck in return. Will they really come through on their promise? Would Americans really risk New York for Paris? This dilemma necessarily leads allies to question whether security guarantees can be trusted.²⁶

Because of these complexities, a defender practicing extended deterrence must project its intention to intervene on behalf of the guaranteed party in advance of conflict. Alliances can help it do so. By making formal and public commitments—rather than ad hoc and informal ones—the defender signals to the world its intentions to protect the ally.²⁷ Formal alliances place the defender in an advanced commitment, and if it fails to respond when an ally is attacked, it may suffer politically costly reputational damage. A defender might also demonstrate the trustworthiness of its guarantee by signaling early its military capability on allied territory. By forward deploying “trip wire” troops or moving major military platforms into an ally’s territory, it shows that an adversary cannot attack the territory without involving the defender.²⁸

Before the emergence of long-range power-projection technology, it was nearly impossible for even a major power to extend deterrence to multiple allies that lay oceans away. But with the invention of bombers, missiles, and nuclear weapons, a once-impossible task became feasible for the United States. The country also had stronger interest in assuming this ambitious mission, lest its most valuable military and economic partners face quick destruction, making it the potential next target of attacks.

American planners focused on these logics. Numerous sources show that, as planners crafted postwar strategy, they discussed how they could use deterrence to prevent the outbreak of another catastrophic war. Writing to Secretary of State George Marshall in 1948, Kennan argued that the Atlantic alliance should not only defend Western Europe but also deter attacks against it.²⁹ In 1948 the Joint Chiefs of Staff worried mightily about how the United States would be able to defend Europe, given the relative weakness of prospective allies there—but the Joint Chiefs acknowledged that the pact had great deterrent value.³⁰ The Americans also emphasized the value of deterrence in an effort to win over skittish European allies. Recall that Europeans insisted the United States automatically declare war in case of an attack, but American leaders refused lest they run into congressional opposition and potential constitutional roadblocks. To assuage the Europeans, they replied that the pact’s purpose was deterrence: the US security guarantee would prevent Europe from being attacked at all.³¹

Deterrence also drove alliance commitments in Asia. Dulles argued that the United States could deter attacks throughout Asia from its position on the Japanese archipelago, particularly if Japan was strong.³² During the Korean War, the US intelligence community believed a security treaty with South Korea would allow the United States to establish what is known as intrawar deterrence, whereby an adversary in an ongoing war is dissuaded from escalating. By establishing effective deterrence in the midst of conflict, the United States might deter future Soviet-backed attacks on the South. With a US alliance in place, any Soviet-backed onslaught against South Korea—which was already illegal under international law—would become too risky.³³

Similarly Taiwan came to be seen as a deterrence asset. During the Chinese Civil War, senior officials dismissed Taiwan’s deterrent value, arguing that the United States could not be an effective security guarantor in the circumstances. But after the communist victory, these strategists reconsidered. If America’s security interests lay in limiting Chinese power and disrupting the Sino-Soviet alliance, then Taiwan had a role to play. By 1954 the chairman of the Joint Chiefs was arguing that only US troops could keep the Chinese from overrunning Taiwan completely. And because the United States had a military-assistance group on the island and patrolled the Taiwan Straits, others argued that Washington had already made a de facto commitment to Taiwan’s security, so it should sign an alliance treaty to reap full deterrence benefits.³⁴ This was still not an easy choice, because, as the National Security Council acknowledged, a US alliance with Taiwan would help to ensure that there would be two separate Chinas. If the Republic of China had American backing, neither the communists nor the nationalists could be destroyed without a world war.³⁵ Deterrence, if successful, would freeze the cross-Straits conflict in a stalemate. Indeed, deterrence seemed to be so powerful that it could reshape Cold War geopolitics altogether.

Allying to Assure … and Control

A third set of alliance motivations emerges from the difficulties entailed in making extended deterrence promises believable, and the coercive options that become available to deterrence-extending states. In addition to defending against or deterring attacks, formal alliance gives a defender opportunities to assure its allies that their security is in fact being protected.³⁶

Assurance is difficult but often necessary to establish the credibility of a security commitment. To be credible, a defender must have reason to act as it says it will, coming to the ally’s defense even at risk to itself. But, as we have seen, it is understandable that both allies and potential adversaries would doubt a defender’s promises. This is especially the case when there is severe asymmetry between the defender and its allies. The weaker state is expecting to be defended, while knowing that it cannot reciprocate. Why would the defender follow through at great cost to itself? Moreover, the weaker ally never really knows what the defender is planning. Only the defender’s leaders possess full information about whether they will really uphold their alliance commitments in wartime, and even they may not be certain until crisis arises. This leaves allies short of information and with a nearly unquenchable thirst for assurance. To slake it, the defender can deploy signs of commitment, such as cooperative military training and planning, regular diplomatic dialogues, and information and intelligence sharing. These signs of commitment aim to persuade the ally that its security is entwined with that of its guarantor, assuaging worries.

But if the cost of assurance is taxing to deterrence-extending states, they also gain an important benefit. The fears of weaker allies reflect their dependency, and that gives defenders control.

The weaker ally knows it cannot easily secure a new defensive guarantee, so it is beholden to its guarantor. The superpower’s extended deterrence is a more potent source of defense than the weaker state can accomplish on its own through conventional self-defense and less costly than pursuing its own nuclear arsenal.³⁷ So weak allies do what they can to retain the defender’s favor. They grant base access and other defensive benefits to the defender and may also cede to the defender some leverage over their national security policy. Dependence makes the weaker ally more susceptible to sanctions and political pressure, which in turn keep it from pursuing destabilizing activities.³⁸

Deterrence-extending states can use their leverage for all sorts of ends. A guarantor may seek to ensure that its ally does not develop military systems that undermine its own strategy—for instance, an independent nuclear arsenal that complicates lines of authority and makes deterrence more difficult to uphold. As Victor Cha has shown, a guarantor may also convince its ally to abandon dangerous interests that it does not share, such as retaking territory lost in a prior war. The defender may further insist that the ally make consequential security decisions in close coordination—a boon when allies have been weakened by war but can be rehabilitated as strong and prosperous regional players. In cases like these, the defender is capitalizing on asymmetry by implicitly threatening to remove the alliance guarantee if the ally fails to comply. The very same asymmetry that can saddle the defender with extra assurance responsibilities pays off when the defender gains opportunities to shape weaker allies’ behavior.³⁹

Control over allies may bestow a security guarantor with yet another benefit: leverage in negotiations with the adversary. The guarantor’s influence over allies’ behavior provides chips in those negotiations. For example, by promising to stop its ally from developing nuclear weapons or retaking disputed territory, the defender can gain a coercive edge over a potential foe.

With each new alliance, US policymakers sought to achieve some measure of assurance and control. The Atlantic alliance was, at heart, an assurance mechanism from the start. US officials’ central worry was that an economically and militarily decimated Europe would succumb to Soviet pressure. Alliances would provide the assurance Europeans needed to recover even as the Soviet threat loomed—the origin of the term “security umbrella.”⁴⁰ Perhaps the strongest example of reassurance at work was the US relationship with West Germany. The United States hoped West Germany would redevelop its industrial capacity and eventually integrate into NATO. But Washington did not give Bonn a free hand. By controlling West Germany’s rearmament and wider revival, the United States could also reassure other European allies that their former adversary would be restored as a benign regional actor.

Assurance and control were also compelling logics in Asia. Like Germany, Japan could be revived industrially and rearmed defensively, without unduly spooking other partners. The United States could use its control over Japan to reassure Asian countries that Tokyo would not be allowed to become aggressive again. The United States could also reassure those countries using treaties. Australia, New Zealand, and the Philippines were all deeply concerned about America’s alliance with Japan, and Washington assuaged them by giving them guarantees of their own, thereby facilitating Japan’s return to the world stage as a useful ally.⁴¹ America’s first three Asian alliances all sought to carefully rehabilitate Japan without causing regional alarm.

And, as we have seen, in South Korea a security guarantee enabled the United States to assure and restrain President Rhee. The Korean case became a model for Taiwan. Dulles, invoking the new Korea alliance, argued that the United States could begin treaty negotiations with Taiwan if Chiang agreed to curb his offensive instincts. The treaty would be exclusively defensive in nature and would make clear that the United States would not support aggression by Taipei against the People’s Republic of China. Chiang ultimately agreed to these terms.⁴²

Evolving Alliance Logics

While forward defense, deterrence, and allied assurance and control held as central logics across America’s alliances, they did not feature in each pact in the same combination. Where potential allies lay further afield from adversaries, as in the case of Australia and New Zealand, forward defense and deterrence were less significant. There, US planners did not invest in integrated military planning, preferring to save resources for the defense of Northeast Asia. Instead the pacts with Australia and New Zealand were primarily motivated by the desire to reassure allies. Indeed, much of the Pacific alliance system began as an effort to assure a jittery region that Japan would be rehabilitated as a benign actor, and commensurately to exert control over Tokyo. The United States did not ally with Australia primarily for reasons of direct defense. It did so in order to gain Australia’s confidence in and support for Washington’s regional security system, which, in turn, afforded the United States greater strategic opportunities.

The goals of defense, deterrence, and assurance manifested in US efforts in both Western Europe and Asia, despite the fact that Washington took different approaches to the two regions. NATO was conceived as a holistic multilateral alliance from the start because US deterrence and defense efforts focused on a single, if vast, front line. In Asia, defense and deterrence were no less important motivators, but the discontinuous maritime geography in the region—and the need to defend allies against distinct adversaries like the Soviet Union, China, and North Korea—meant that deterrence and defense could be better accomplished through more focused, bilateral pacts. Both approaches—multilateral and bilateral—enabled assurance and control through varying mechanisms. America’s alliance logics themselves prevented a one-size-fits-all approach.

The power of these logics was only augmented as the first few years of the Cold War played out. When Washington’s alliance entrepreneurship began—in 1948–1949 in Europe and 1950–1951 in Asia—American leaders recognized the need for forward defense and deterrence but hoped that the nuclear capabilities would keep its forward basing requirements modest. The strategic surprise inflicted by the Korean War, however, demonstrated that Soviet-backed adventurism was no abstract specter. It would have to be met with conventional power, so American strategy shifted in both theaters. In Europe the United States bolstered forward defenses and formed NATO’s integrated military command in 1952. In Asia the end of the Korean War and the collapse of the French position in Vietnam led American policymakers to extend additional pacts in South Korea, Taiwan, and Southeast Asia to strengthen deterrence not only against the Soviet Union but other communist challengers as well. The Atlantic alliance extended membership to Greece, Turkey, and West Germany around the same time.

When the Korean War revealed the limits of Washington’s early Cold War alliance strategy, the United States did not abandon the underlying logics. It redoubled its commitment to them. To some extent, the US appetite for alliance grew with the eating. In 1948 the country’s foreign policy minds were hesitant to sign a defense treaty with Europe; by 1954 they were all too eager in Southeast Asia.

These new alliances were definitively not altruistic, nor were they instruments for fighting and winning a given war. They were innovative peacetime tools for securing a novel conception of the national defense. One by one, weaker allies took their place in a strategy that aimed to hold the balance of power in Europe and Asia and thereby keep the United States safe and secure.

America’s Cold War Alliance Record

America’s postwar planners may have produced an innovation in statecraft, but did their alliance strategy work? International relations scholarship suggests that alliances do advance the goals American planners set out in the early Cold War. Forward-deployed troops are proven to enhance deterrence in alliances. Alliances have also been shown to significantly lower the risk of conflict involving the allied states. And scholars have found that alliances with nuclear-armed states are especially likely to improve deterrence and reduce the risk that smaller countries will be targeted by adversaries.⁴³ The Cold War historical record reflects these findings. With an alliance in force, no US ally was a victim of an unprovoked attack, and no ally invoked its treaty commitment with the United States.

The United States also gained from its leverage over partners, most notably West Germany and Japan. Under US protection, the countries not only became central to America’s military position in Europe and Asia respectively, but they also became consolidated democracies with vibrant economies—leading regional powers in their own right. Along the way, they adopted domestic and foreign policies that were highly beneficial to their patron. Former adversaries became fulcrums of American strategy in Europe and Asia, and since the Cold War ended, Japan and Germany have continued to play this role.

Scholars have also found strong evidence that security guarantees stem the spread of the world’s most dangerous weapons. States that receive security guarantees from nuclear-armed powers are significantly less likely to pursue or acquire their own nuclear weapons. Cold War history demonstrates this nonproliferation effect. Between the 1960s and 1980s, the United States convinced West Germany, South Korea, and Taiwan to abandon nuclear weapons programs through implicit or explicit threats to end alliances.⁴⁴

Moreover, alliances provided Washington with a benefit that early Cold War strategists did not anticipate: alliances lowered the cost of military and political action worldwide. Since the early 1950s, American treaty allies have joined every war the country has fought, although they were not required to by the terms of the alliance. European allies contributed over 20,000 troops to the Korean War, and South Korea alone sent 300,000 soldiers to Vietnam. Such multilateralism also improves the perceived international legitimacy of military interventions, as in Korea and in the Balkans after the Cold War. Evidence also suggests that by maintaining close defense relationships, the United States gained from allied diplomatic cooperation that would otherwise have been harder to secure.⁴⁵

America’s alliance record was not unblemished, however. American allies were involved in some interstate violence, especially where treaty application was contested or unclear. And deterrence did not prevent the use of force at all levels of the conflict spectrum. Taiwan and South Korea were involved in crises short of war despite the US security guarantee. Within NATO’s borders, Greece and Turkey have skirmished with one another, and the alliance may have exacerbated tensions between them.⁴⁶ And, late in the Cold War, the United Kingdom went to war with Argentina over the Falklands. The closest of US allies was at war with a member of the Rio Pact, although the United States itself did not become involved militarily.

The United States also failed to stop its French ally from acquiring nuclear weapons, and in 1966 France left the NATO military structure rather than submit its weapons to centralized control. The French departure was part of a broader assurance crisis that seized NATO as the Soviets acquired intercontinental ballistic missiles, precipitating a New York-for-Paris extended deterrence dilemma.⁴⁷ Elsewhere, Washington’s attempt to establish SEATO never advanced, and the organization foundered—alliance setbacks to which I return in Chapter 3.

But, despite these stumbles, America’s alliance record is actually more impressive than may be apparent. The United States granted security guarantees to states that faced high likelihood of attack. These states were especially likely to seek their own nuclear weapons and other independent defensive capabilities and to become embroiled in Cold War conflicts. Against all odds, they did not.

Still, could it be that the success of America’s strategy owes to some cause other than alliances? How do we know it was alliance that maintained peace? Political scientists have established that states with alliances are less likely to become victims of attack, but it is harder to confirm exactly why this is so in any given case. Was an adversary deterred from attacking the ally because of the defender’s strong signals of commitment, or did the adversary never wish to attack at all? Indeed, while the logic of deterrence is straightforward, international relations scholars cannot calculate exactly whether it is working.⁴⁸

Furthermore we do not know if the power of alliances lay in the security guarantees themselves or in the process by which the United States formed them in the first place.⁴⁹ Washington did not extend security guarantees everywhere it might have, choosing instead to grant defense pacts to states with which it shared clear interests and adversaries. This perfectly sensible approach to strategy makes it hard to know whether formal alliances intrinsically have great deterrent power, or whether the preexisting confluence of interests between the United States and its closest partners was enough to send strong signals to Cold War adversaries.

It is also possible that other post-1945 forces help to explain the security the United States and its allies enjoyed. The post-World War II period has been called the “long peace” due to the lack of overt war between major powers, which, in turn, helped to preserve the stability of smaller states and international politics as a whole.⁵⁰ To be sure, there have been numerous international conflicts since 1945, but none saw the leading states square off against each other directly. Explanations for this period of relative calm include the structure of the Cold War international system, divided as it was between American and Soviet camps; the presence of nuclear weapons on both sides of the competition; increasing economic interdependence, which reduced the incentives to go to war; the spread of democracy and its ostensibly pacifying effects; and international law and strong norms against territorial conquest.⁵¹

These are not necessarily contrary explanations, however. Indeed, each can be linked to the power of US alliances. Alliances are thought to be more stable in bipolar systems; nuclear weapons implicitly support US security guarantees; alliances and beneficial trade flows are closely connected; nearly all American allies are now consolidated democracies, although they did not begin as such; and alliances explicitly invoke international law that prohibits aggressive conflict and outlaws territorial conquest.⁵² Alliances are not only inextricable from some of these other potentially salutary forces but directly exploit and advance them. If alliances’ precise pacifying effects are vexing to measure, it is in part because alliances are vectors for some of the other post-1945 forces that are thought to have contributed to peace.

In sum, when peace prevails and crises do not arise—that is, when general deterrence is effective—it seems likely that the power of alliances is at play, but it is difficult to confirm this with certainty. It is easier, however, to examine the role that alliances play in immediate deterrence—efforts to resolve brewing crises before they spiral into conflict. A case study of one of the highest-stakes standoffs of the Cold War helps to demonstrate how forward defense, deterrence, and allied control and assurance may have helped the United States and its allies defuse wars before they started.

The 1961 Berlin Crisis

The 1961 Berlin Crisis was the last of three major political flare-ups over the contested status of the German city. It is also a primary example of how an alliance allowed the United States to deter potential conflict, defend its national interest, and exert control over its ally to facilitate the settlement of a crisis.

At the end of the Second World War, Germany was partitioned between the victorious allies. The Soviet Union would administer eastern Germany, and the United States, Britain, and France would divide authority over the western part. The four powers would share occupation of Berlin, which was located a hundred miles inside the Soviet zone. At first American policymakers embraced the idea: four-power administration would keep Germany as a whole weak, and the United States could run things as it wished in its own areas. However, by the end of 1947, with the Cold War seizing Europe, the Western powers concluded that the Soviet Union would not cooperate in overseeing Germany. The country would have to be formally divided, and a less-than-sovereign West German state established to protect the Western Allies’ zones.

In 1948 the Soviets responded by cutting off ground access between Berlin and West Germany, forcing the allies to stage a year-long airlift to supply their sectors. The blockade piqued Western fears that their position in Berlin was essentially indefensible. Western leaders worried that they might have to withdraw from the city altogether.⁵³ The Joint Chiefs wondered if “some justification might be found for withdrawal of occupying forces without undue loss of prestige.”⁵⁴ Ultimately the blockade accelerated the process of building a West German state. It catalyzed the formation of the NATO alliance that same year. When the Soviets broke the US atomic monopoly in 1949 and North Korea overran the South in 1950, the United States only became further committed to the strategic defense of Western Europe. The Soviets, in turn, became more fearful of West German rearmament. Under these circumstances, West Berlin became a proving ground for the perilous postwar settlement.⁵⁵

Fig. 2.1   Divided Germany and Berlin

After 1949 Germany was officially divided into the Federal Republic in the west and the Democratic Republic, or GDR, in the east. Berlin remained suspended in the Democratic Republic, providing a porous border through which millions of Easterners crossed into the West during the 1950s. This mass migration drained the Democratic Republic, with grave economic consequences. Then, in 1955, the Federal Republic became a full-fledged NATO member, to Moscow’s consternation. West Germany began rearming with Western imprimatur. The Soviets rightly suspected that West German leadership was seriously considering building an independent nuclear arsenal. The Soviets responded by forming and investing in the Warsaw Pact, which would defend against NATO and its members. East Germany was included in the alliance.56

The next major Berlin eruption came during the Eisenhower administration. In 1958, with fears about West German strength mounting, Soviet Premier Nikita Khrushchev issued an ultimatum to the Western powers. In six months, he said, he was going to sign a peace treaty with East Germany, ending the Soviet occupation and handing over all administrative functions to the East German government. That meant the Western powers would have the same amount of time to withdraw from Berlin. If they wanted to keep their access and military presence there, they would have to negotiate with the newly empowered East German government.⁵⁷

The Western powers objected, insisting that the Soviet plan would undermine their rights to the city, as established in the postwar settlement. Khrushchev responded that the allies had already abrogated their rights by bringing West Germany into NATO. Khrushchev’s deadline passed without consequence in May 1959, but he did not withdraw the ultimatum. The threat to sign the peace and eject the Western powers persisted for the rest of Eisenhower’s presidency. With the status of Berlin a lingering question, the West German military continued to strengthen, and NATO integration proceeded apace.⁵⁸

When John F. Kennedy was elected in 1960, he was well aware that he faced a deferred showdown on the status of Berlin. Thus one of the new administration’s first major foreign policy moves was the introduction of a “flexible response” strategy anticipating tensions in Germany. Flexible response was intended to make more credible the large-scale US conventional defense guarantee in Western Europe, so that the United States would not have to immediately escalate to promises of nuclear war in the event that West Berlin was threatened.⁵⁹ Less than five months after Kennedy’s inauguration, Khrushchev revived his threats over Berlin.

The tension was thick in June 1961, when Kennedy and Khrushchev met in Vienna for their first bilateral summit. The two leaders made an odd pair. Kennedy was a forty-four-year-old foreign policy novice. He had just experienced a stinging national security defeat in his flubbed Bay of Pigs invasion, for which his Soviet counterpart had excoriated him.⁶⁰ Khrushchev was an experienced statesman of seventy-five, known to be of erratic and irascible temperament. And he held at the ready the Berlin ultimatum, which he could easily renew. Feeling “unabating” pressure from GDR First Secretary Walter Ulbricht, the Soviet premier did exactly that.⁶¹ Khrushchev restated his intent to sign the peace treaty with East Germany, terminating the occupation and, with it, Western access rights to Berlin. Under further pressure from Soviet hardliners who demanded swift action, he set a fall deadline for the treaty. Kennedy responded that the allies were not in Berlin by East German invitation but by virtue of their contractual postwar rights, which the Soviet Union could not abrogate. Kennedy also announced that Western Europe, West Germany, and West Berlin were vital American interests and would be treated accordingly.⁶²

Khrushchev responded by threatening war if the status of Berlin was not resolved to his satisfaction. In doing so, he sought to call Kennedy’s bluff. West Berlin was not militarily vital to the United States in any strict sense; the defense of West Germany was not contingent on it. Yet Kennedy worried that if he lost access to West Berlin, West Germany would slip out of the Western camp, either becoming neutral or realigning with the USSR.⁶³ Kennedy quickly began to coordinate with Britain and France as to the precise position the allies should take and the means they were willing to commit to preserve their position in Berlin.⁶⁴ British Prime Minister Harold Macmillan and French President Charles de Gaulle quickly made public statements declaring their rights in Berlin could not be dissolved.

Upon his return to the United States, Kennedy established a task force on Berlin. The group concluded that Moscow’s aims were threefold: it likely sought the permanent partition of Germany; it hoped to end allied rights and access to Berlin; and it sought to gradually erode the rights of West Berliners, neutralizing Western power in the city. The Kennedy team began to coordinate contingency planning with its French and British allies. Planners anticipated the actions they would take under three conditions: 1) the Russians signed a peace treaty with East Germany; 2) the Russians signed the treaty and interrupted Western civilian access to Berlin; 3) the Russians signed the treaty and barred Western military access to Berlin.⁶⁵

The superpowers also sought to demonstrate and intensify their military commitments to Berlin. In early July Khrushchev made a public speech restating his ultimatum. He also announced a one-third increase in the budget for the Soviet armed forces. And he sent separate notes to Kennedy, Macmillan, and de Gaulle threatening different American, British, and French national interests in hopes of dividing the alliance. Instead the allies coordinated their responses, replying as Kennedy had in Vienna: the Soviet Union had no legal basis for terminating Western rights in Berlin, and its threats to do so were the real danger to peace.⁶⁶

In late July Kennedy made a speech of his own. He declared the United States’ defensive intentions in Berlin but insisted he would protect Western rights in the city. He requested and received an additional $3.5 billion in military spending to fund Army personnel, airlift capacity, munitions, and other equipment. He also announced that he would triple the size of the draft, call up Army reserves, and field six new Army and two new Marine divisions.⁶⁷ Despite the urging of some of his advisors, however, Kennedy opted not to declare a state of emergency over Berlin, judging this to be excessively escalatory and preferring to save the option in case it became necessary later. He wanted military pressure to be credible, but he also wanted to leave room for Soviet retreat.⁶⁸

Khrushchev was impressed by the US president’s demonstrated commitment to Berlin and the seeming cohesion of the alliance in the midst of crisis. Soviet intelligence also detected Western preparations to reinforce Berlin in case of conflict with Moscow, which added credibility to Kennedy’s words and his budgetary move.⁶⁹ Under duress, Khrushchev authorized a KGB disinformation campaign to exaggerate Soviet military strength around Berlin, revealing that he “took very seriously the military might of the United States and NATO.”⁷⁰ Having previously told his son Sergei that “no one would undertake war over Berlin,” he now admitted to Soviet allies that “war is possible … they can unleash it.”⁷¹

Since the Vienna meeting, East Berlin had been hemorrhaging a thousand refugees a day. Khrushchev had to find a solution or face the wrath of hardliners at his Party Congress. What to do, now that the Allies had shown their resolve? He was faced with a dilemma: he could escalate, gambling for a peace treaty by risking nuclear war with NATO. Or he could settle for more modest objectives, cutting off the refugee escape route through West Berlin. He chose the second option.⁷²

On August 7 Khrushchev declared that he would imminently “close the loophole” that was West Berlin, effectively warning the Western powers not to interfere. On August 12 Ulbricht signed an order to close the border, and by the next morning it was rendered impassable by miles of barbed wire and fencing. The East Germans had been stockpiling construction materials, and just a few days later the Berlin Wall bisected the city.⁷³

Initially both sides sought to avoid further escalation. US intelligence received advance notice that the border would be closed, yet the Western powers did not interfere or even object for two full days after the closure. The Warsaw Pact alerted NATO that the barrier was a temporary measure that would not affect Western access routes. The GDR announced it was imposing travel restrictions on East Berliners but that no action had been taken against West Berliners. In spite of these assurances, Kennedy did call up 148,000 reservists, and he sent his vice president and a new battle group of 1,500 soldiers to Berlin. De Gaulle agreed to increase his troop contribution to NATO by 30 percent. And all three Western powers placed their garrisons on alert. But, in truth, they were relieved. Khrushchev appeared to be solving his own Berlin problem without jeopardizing the Western position. From the Soviet perspective, Hope Harrison writes, “the wall itself was the way … to bury the idea of a German peace treaty.”⁷⁴ Allied leaders hoped the barrier had brought the standoff to an end.⁷⁵

But the 1961 crisis did not end there. In late October a senior American diplomat was stopped at Checkpoint Charlie, a high-traffic crossing between East and West Berlin. He refused to be turned away. Within days ten US and ten Soviet tanks faced one another at the checkpoint. The tanks were loaded with live munitions, and both groups had orders to fire if fired upon. The US Strategic Air Command boosted alert levels; its West Berlin garrison and NATO echoed the alarm, raising again the possibility of a superpower nuclear exchange.

Kennedy and Khrushchev took to a backchannel to seek resolution. They agreed that the standoff had catastrophic potential and decided to withdraw. The Soviet tanks move backward by five meters; the Americans followed suit. Each group edged away in turn, until the impasse concluded without incident. It was the superpowers’ only direct military standoff during the Cold War.

In late 1961 the Soviet Union abandoned its ultimatum. The United States had weathered the crisis without bending to Khrushchev’s demands: the allies maintained their position in Berlin, including military and civilian access. By early 1962 Khrushchev declared that a peace treaty was no longer necessary. The four powers did not immediately conclude a formal agreement to resolve tensions, but by 1963 a modus vivendi of sorts had consolidated among them. With the wall in place, the political status quo could now be respected in Berlin and in both halves of Germany; the United States would permanently maintain a large military presence; the NATO alliance would continue to strengthen; and Washington would work to keep West Germany nonnuclear—which it did, by suggesting it might abandon the alliance unless Bonn gave up its nuclear ambitions. With the refugee crisis under control and West German power in check, the Soviet Union could accept the arrangement.⁷⁶ “It’s not a very nice solution,” Kennedy observed, “but a wall is a hell of a lot better than a war.”⁷⁷

Without Alliance: A Berlin 1961 Counterfactual

If NATO had not existed, or West Germany had not been a member of the alliance, the standoff over Berlin might well have been resolved in Moscow’s favor. After all, the Soviets were in the stronger position because the location of the city put its Western defenders at an extraordinary disadvantage. The fact that West Berlin was not intrinsically all that valuable to the United States made it even harder to mount a credible defense.

Washington’s alliances, however, allowed it to pre-commit to the defense of Berlin, bolster its commitment as the crisis intensified, and coordinate responses with Britain and France. West Germany’s NATO membership also gave Washington leverage over rearmament in the country, which mollified the Soviets and gave them room to back down. The Soviets were dissuaded from pursuing maximalist objectives.

The United States would have had a far more difficult time defending its position in West Berlin if not for its alliance commitments. Without NATO, there would not have been 12,000 allied troops stationed in West Germany in 1961. The United States probably would not have had access to bases to host additional Army and Marine divisions or the high-end military equipment needed to thwart a blockade. The allies would not have had garrisons they could alert and stand down to signal their intentions. Nor would they have had tanks in the area, to send to Checkpoint Charlie when American access rights to Berlin were denied. Even with these in place, Khrushchev may have doubted whether the United States would really fight a nuclear war over Berlin, but he could not deny that Kennedy was at least treating the city as though it were a vital American interest.

Alliance also enabled timely, credible augmentation of the Western commitment to West Berlin during the crisis, deterring the Soviet Union without escalating the standoff unduly. During July and August, the Americans, the British, and the French all demonstrated a willingness to dedicate more troops to defend Berlin militarily. Without the alliance, the three powers would not have had contingency planning mechanisms to allow them to coordinate Berlin policy swiftly and to ensure that the Soviet Union did not find many cracks in their position. Their unified front helped to convince Khrushchev that they might really be willing to fight and that the wall was a preferable option. Their incremental use of pressure—another product of coordination—left him room to back down, and he took it.

Counterintuitively, the heavy US military presence in Germany, and West German NATO membership, also helped to convince Khrushchev that he could settle for something less than his ultimatum. Kennedy was sincere in his efforts to keep West Germany from developing its own nuclear weapons and even argued to British and French allies that they should abandon their nuclear weapons to encourage Bonn to stop.⁷⁸ Khrushchev would have preferred a weak West Germany with no NATO membership or Western military presence, but he could accept both if they restrained West Germany’s pursuit of nuclear weapons. Coupled with credible defensive and deterrent options, the US promise to exert control over West Germany helped to end the standoff.

Against all odds, the United States and its allies would go on to retain their political position in West Berlin for the entire Cold War, keeping it out of Soviet hands. A political partition that seemed preposterously unsustainable in the 1950s managed to endure for four decades with the help of a defense pact.

A critic might contend that the United States would never have been in Berlin without the NATO alliance—that the commitment itself created the need for forward defense, deterrence, and alliance restraint. The United States would not have had to use an alliance to salvage its position in Berlin if it had not made an untenable political commitment in the first place. But this argument is flimsy because the division of Germany preceded the US peacetime alliances. The United States and its allies were committed to Germany before Washington decided to form the Atlantic alliance, supervise German rearmament, and bring West Germany into the fold. The political commitment to Berlin may have been dubious, but the political and military commitment to West Germany—the alliance—helped to salvage it.

One might also argue that the 1961 crisis is an unrepresentative example of a clear alliance victory—perhaps an extreme case in which the Soviet Union had atypically revisionist intentions that the United States managed to thwart. To be sure, the Soviet Union did not seek to take territory or subvert the sovereignty of US allies everywhere. Similar dynamics, however, can be observed in other Cold War crises over divided, frontline territories. During several dangerous crises after the Korean War, forward defense, deterrence, and alliance restraint supported the US objective of preventing another war between Seoul and a Soviet proxy. Analogous forces prevailed in the Taiwan Straits Crises of 1954 and 1958.⁷⁹ Indeed, throughout the Cold War, the United States and its allies had a strong record of bolstering immediate deterrence once a challenge had begun, preventing serious escalation and avoiding war. In several cases divided states that might have easily been overrun by Soviet proxies instead remained peaceful parts of the Western bloc.

Alliance commitments motivated Washington to intervene early and demonstrably in crises along Cold War fault lines, lest it become embroiled in larger and more costly conflicts later. When trouble emerged the United States reinforced its alliance commitments with strong public statements and demonstrations of military force, improving the local balance of power near the standoff at low cost to the United States.⁸⁰ The global balance of power cast a long shadow, too: in any one crisis, the United States and its allies might be outnumbered, but in aggregate terms, their strength dwarfed that of the Soviets.⁸¹ The republic’s shields provided defensive advantages that helped to keep conflicts stable and the Cold War from escalating into an open and catastrophic clash.