Defense In Depth
Why U.S. Security Depends on Alliances—Now More Than Ever
The rise of China will likely be the most important international relations story of the twenty-first century, but it remains unclear whether that story will have a happy ending. Will China's ascent increase the probability of great-power war? Will an era of U.S.-Chinese tension be as dangerous as the Cold War? Will it be even worse, because China, unlike the Soviet Union, will prove a serious economic competitor as well as a geopolitical one?
These issues have been addressed by a wide range of experts -- regionalists, historians, and economists -- all of whom can claim insight into certain aspects of the situation. But China's unique qualities, past behavior, and economic trajectory may well turn out to be less important in driving future events than many assume -- because how a country acts as a superpower and whether its actions and those of others will end in battle are shaped as much by general patterns of international politics as by idiosyncratic factors. Such broader questions about the conditions under which power transitions lead to conflict are precisely what international relations theorists study, so they, too, have something to add to the discussion.
So far, the China debate among international relations theorists has pitted optimistic liberals against pessimistic realists. The liberals argue that because the current international order is defined by economic and political openness, it can accommodate China's rise peacefully. The United States and other leading powers, this argument runs, can and will make clear that China is welcome to join the existing order and prosper within it, and China is likely to do so rather than launch a costly and dangerous struggle to overturn the system and establish an order more to its own liking.
The standard realist view, in contrast, predicts intense competition. China's growing strength, most realists argue, will lead it to pursue its interests more assertively, which will in turn lead the United States and other countries to balance against it. This cycle will generate at the least a parallel to the Cold War standoff between the United States and the Soviet Union, and perhaps even a hegemonic war. Adherents of this view point to China's recent harder line on its maritime claims in the East China and South China seas and to the increasingly close relations between the United States and India as signs that the cycle of assertiveness and balancing has already begun.
In fact, however, a more nuanced version of realism provides grounds for optimism. China's rise need not be nearly as competitive and dangerous as the standard realist argument suggests, because the structural forces driving major powers into conflict will be relatively weak. The dangers that do exist, moreover, are not the ones predicted by sweeping theories of the international system in general but instead stem from secondary disputes particular to Northeast Asia -- and the security prevalent in the international system at large should make these disputes easier for the United States and China to manage. In the end, therefore, the outcome of China's rise will depend less on the pressures generated by the international system than on how well U.S. and Chinese leaders manage the situation. Conflict is not predetermined -- and if the United States can adjust to the new international conditions, making some uncomfortable concessions and not exaggerating the dangers, a major clash might well be avoided.
A GOOD KIND OF SECURITY DILEMMA
Structural realism explains states' actions in terms of the pressures and opportunities created by the international system. One need not look to domestic factors to explain international conflict, in this view, because the routine actions of independent states trying to maintain their security in an anarchic world can result in war. This does not happen all the time, of course, and explaining how security-seeking states find themselves at war is actually something of a puzzle, since they might be expected to choose cooperation and the benefits of peace instead. The solution to the puzzle lies in the concept of the security dilemma -- a situation in which one state's efforts to increase its own security reduce the security of others.
The intensity of the security dilemma depends, in part, on the ease of attack and coercion. When attacking is easy, even small increases in one state's forces will significantly decrease the security of others, fueling a spiral of fear and arming. When defending and deterring are easy, in contrast, changes in one state's military forces will not necessarily threaten others, and the possibility of maintaining good political relations among the players in the system will increase.
The intensity of the security dilemma also depends on states' beliefs about one another's motives and goals. For example, if a state believes that its adversary is driven only by a quest for security -- rather than, say, an inherent desire to dominate the system -- then it should find increases in the adversary's military forces less troubling and not feel the need to respond in kind, thus preventing the spiral of political and military escalation.
The possibility of variation in the intensity of the security dilemma has dramatic implications for structural realist theory, making its predictions less consistently bleak than often assumed. When the security dilemma is severe, competition will indeed be intense and war more likely. These are the classic behaviors predicted by realist pessimism. But when the security dilemma is mild, a structural realist will see that the international system creates opportunities for restraint and peace. Properly understood, moreover, the security dilemma suggests that a state will be more secure when its adversary is more secure -- because insecurity can pressure an adversary to adopt competitive and threatening policies. This dynamic creates incentives for restraint and cooperation. If an adversary can be persuaded that all one wants is security (as opposed to domination), the adversary may itself relax.
What does all this imply about the rise of China? At the broadest level, the news is good. Current international conditions should enable both the United States and China to protect their vital interests without posing large threats to each other. Nuclear weapons make it relatively easy for major powers to maintain highly effective deterrent forces. Even if Chinese power were to greatly exceed U.S. power somewhere down the road, the United States would still be able to maintain nuclear forces that could survive any Chinese attack and threaten massive damage in retaliation. Large-scale conventional attacks by China against the U.S. homeland, meanwhile, are virtually impossible because the United States and China are separated by the vast expanse of the Pacific Ocean, across which it would be difficult to attack. No foreseeable increase in China's power would be large enough to overcome these twin advantages of defense for the United States. The same defensive advantages, moreover, apply to China as well. Although China is currently much weaker than the United States militarily, it will soon be able to build a nuclear force that meets its requirements for deterrence. And China should not find the United States' massive conventional capabilities especially threatening, because the bulk of U.S. forces, logistics, and support lie across the Pacific.
The overall effect of these conditions is to greatly moderate the security dilemma. Both the United States and China will be able to maintain high levels of security now and through any potential rise of China to superpower status. This should help Washington and Beijing avoid truly strained geopolitical relations, which should in turn help ensure that the security dilemma stays moderate, thereby facilitating cooperation. The United States, for example, will have the option to forego responding to China's modernization of its nuclear force. This restraint will help reassure China that the United States does not want to threaten its security -- and thus help head off a downward political spiral fueled by nuclear competition.
BUT WHAT ABOUT THE ALLIES?
The preceding analysis, of course, overlooks a key feature of U.S. foreign policy -- the important security alliances the United States maintains with Japan and South Korea, as well as other U.S. security commitments in Northeast Asia. Yet although adding U.S. allies yields a more complex picture, it does not undercut the overall optimism about China's rise. Instead, it raises the question of just how essential regional alliances in the Pacific are to U.S. security.
The United States' alliance commitments have been remarkably stable since the beginning of the Cold War, but China's rise should lead to renewed debate over their costs and benefits. Arguing along lines similar to those mentioned above -- that the United States can be secure simply by taking advantage of its power, geography, and nuclear arsenal -- so-called neo-isolationists conclude that the United States should end its alliances in Europe and Asia because they are unnecessary and risky. If the United States can deter attacks against its homeland, they ask, why belong to alliances that promise to engage the United States in large wars on distant continents? Protecting U.S. allies in Asia might require the United States to engage in political skirmishes and military competition that will strain its political relations with China. According to neo-isolationists, in short, China's rise will not jeopardize U.S. security, but maintaining current U.S. alliances could.
Advocates of selective engagement, in contrast -- an approach similar to existing U.S. policy -- claim that their chosen strategy is also consistent with the broad outlines of structural realism. Whereas neo-isolationists want the United States to withdraw from forward positions in order to avoid being sucked into a regional conflict, those favoring selective engagement argue that preserving U.S. alliance commitments in Europe and Asia is the best way to prevent the eruption of a conflict in the first place.
Examining how existing U.S. alliance commitments are likely to interact with China's rise is thus a crucial issue, with implications for both regional policy and U.S. grand strategy more generally. If the United States maintains its key alliance commitments, as is likely, it will need to extend its deterrent to Japan and South Korea while facing significantly larger and more capable Chinese conventional military forces. In many ways, this challenge will be analogous to the one the United States faced in extending its deterrent to Western Europe during the Cold War. Both superpowers had robust nuclear retaliatory capabilities, and the Soviet Union was widely believed to have superior conventional forces that were capable of invading Europe.
Back then, experts debated whether U.S. capabilities were sufficient to deter a massive Soviet conventional attack against Europe. They disagreed over whether NATO's doctrine of flexible response -- which combined large conventional forces with an array of nuclear forces -- enabled the United States to make nuclear threats credible enough to deter a Soviet conventional attack. Doubts about U.S. willingness to escalate reflected the clear danger that U.S. escalation would be met by Soviet nuclear retaliation. Nevertheless, the stronger argument in this debate held that U.S. strategy did provide an adequate deterrent to a Soviet conventional attack, because even a small probability of U.S. nuclear escalation presented the Soviets with overwhelming risks. The same logic should apply to a future Chinese superpower. The combination of clear alliance commitments, forward deployed conventional forces, and large survivable nuclear forces should enable the United States to deter a Chinese attack on either Japan or South Korea.
Confidence in the U.S. deterrent is likely to be reinforced by relatively good relations between the United States and China. Those who feared that the United States could not extend its deterrent to Western Europe believed that the Soviet Union was a highly revisionist state bent on radically overturning the status quo and willing to run enormous risks in the process. There is virtually no evidence suggesting that China has such ambitious goals, so extending the U.S. deterrent should be easier now than during the Cold War. And even in the unlikely event that China evolved into such a dangerous state, deterrence would still be possible, albeit more difficult.
Some realist pessimists argue that in order to be highly secure, China will find itself compelled to pursue regional hegemony, fueling conflict along the way. However, China's size, power, location, and nuclear arsenal will make it very challenging to attack successfully. China will not need to push the United States out of its region in order to be secure, because a forward U.S. presence will not undermine China's core deterrent capabilities. A major U.S. withdrawal, moreover, would not automatically yield Chinese regional hegemony, because Japan and South Korea might then acquire stronger conventional military capabilities and nuclear capabilities of their own, greatly reducing China's coercive potential. A Chinese drive for regional hegemony, therefore, would be both unnecessary and infeasible.
The United States' forward military presence does enhance its power-projection capabilities, which threaten China's ability to protect its sea-lanes and coerce Taiwan. But the U.S. alliance with Japan also benefits China by enabling Japan to spend far less on defense. Although the United States' power far exceeds Japan's, China has seen the alliance as adding to regional stability, because it fears Japan more than the United States. As China grows more powerful, it may increasingly resent U.S. influence in Northeast Asia. But unless U.S.-Chinese relations become severely strained, China is likely to accept a continuing U.S. presence in the region, given the alternatives.
ACCOMMODATION ON TAIWAN?
The prospects for avoiding intense military competition and war may be good, but growth in China's power may nevertheless require some changes in U.S. foreign policy that Washington will find disagreeable -- particularly regarding Taiwan. Although it lost control of Taiwan during the Chinese Civil War more than six decades ago, China still considers Taiwan to be part of its homeland, and unification remains a key political goal for Beijing. China has made clear that it will use force if Taiwan declares independence, and much of China's conventional military buildup has been dedicated to increasing its ability to coerce Taiwan and reducing the United States' ability to intervene. Because China places such high value on Taiwan and because the United States and China -- whatever they might formally agree to -- have such different attitudes regarding the legitimacy of the status quo, the issue poses special dangers and challenges for the U.S.-Chinese relationship, placing it in a different category than Japan or South Korea.
A crisis over Taiwan could fairly easily escalate to nuclear war, because each step along the way might well seem rational to the actors involved. Current U.S. policy is designed to reduce the probability that Taiwan will declare independence and to make clear that the United States will not come to Taiwan's aid if it does. Nevertheless, the United States would find itself under pressure to protect Taiwan against any sort of attack, no matter how it originated. Given the different interests and perceptions of the various parties and the limited control Washington has over Taipei's behavior, a crisis could unfold in which the United States found itself following events rather than leading them.
Such dangers have been around for decades, but ongoing improvements in China's military capabilities may make Beijing more willing to escalate a Taiwan crisis. In addition to its improved conventional capabilities, China is modernizing its nuclear forces to increase their ability to survive and retaliate following a large-scale U.S. attack. Standard deterrence theory holds that Washington's current ability to destroy most or all of China's nuclear force enhances its bargaining position. China's nuclear modernization might remove that check on Chinese action, leading Beijing to behave more boldly in future crises than it has in past ones. A U.S. attempt to preserve its ability to defend Taiwan, meanwhile, could fuel a conventional and nuclear arms race. Enhancements to U.S. offensive targeting capabilities and strategic ballistic missile defenses might be interpreted by China as a signal of malign U.S. motives, leading to further Chinese military efforts and a general poisoning of U.S.-Chinese relations.
Given such risks, the United States should consider backing away from its commitment to Taiwan. This would remove the most obvious and contentious flash point between the United States and China and smooth the way for better relations between them in the decades to come. Critics of such a move argue that it would result in not only direct costs for the United States and Taiwan but indirect costs as well: Beijing would not be satisfied by such appeasement; instead, it would find its appetite whetted and make even greater demands afterward -- spurred by Washington's lost credibility as a defender of its allies. The critics are wrong, however, because territorial concessions are not always bound to fail. Not all adversaries are Hitler, and when they are not, accommodation can be an effective policy tool. When an adversary has limited territorial goals, granting them can lead not to further demands but rather to satisfaction with the new status quo and a reduction of tension.
The key question, then, is whether China has limited or unlimited goals. It is true that China has disagreements with several of its neighbors, but there is actually little reason to believe that it has or will develop grand territorial ambitions in its region or beyond. Concessions on Taiwan would thus risk encouraging China to pursue more demanding policies on those issues for which the status quo is currently disputed, including the status of the offshore islands and maritime borders in the East China and South China seas. But the risks of reduced U.S. credibility for protecting allies when the status quo is crystal clear -- as is the case with Japan and South Korea -- should be small, especially if any change in policy on Taiwan is accompanied by countervailing measures (such as a renewed declaration of the United States' other alliance commitments, a reinforcement of U.S. forward deployed troops, and an increase in joint military exercises and technological cooperation with U.S. allies).
Whether and how the United States should reduce its commitment to Taiwan is clearly a complex issue. If the United States does decide to change its policy, a gradual easing of its commitment is likely best, as opposed to a sharp, highly advertised break. And since relations between Taiwan and China have improved over the past few years, Washington will likely have both the time and the room to evaluate and adjust its policy as the regional and global situations evolve.
The broader point is that although China's rise is creating some dangers, the shifting distribution of power is not rendering vital U.S. and Chinese interests incompatible. The potential dangers do not add up to clashing great-power interests that can be resolved only by risking a major-power war. Rather, the difficulty of protecting some secondary, albeit not insignificant, U.S. interests is growing, requiring the United States to reevaluate its foreign policy commitments.
THE DANGERS OF EXAGGERATION
Realist analyses of how power transitions will play out are based on the assumption that states accurately perceive and respond to the international situations they face. Realist optimism in this case thus rests on the assumption that U.S. leaders appreciate, and will be able to act on, the unusually high degree of security that the United States actually enjoys. Should this assumption prove incorrect, and should the United States exaggerate the threat China poses, the risks of future conflict will be greater. Unfortunately, there are some reasons for worrying that the assumption might in fact be wrong.
For example, the popular belief that a rising China will severely threaten U.S. security could become a self-fulfilling prophecy. Should Washington fail to understand that China's growing military capabilities do not threaten vital U.S. interests, it may adopt overly competitive military and foreign policies, which may in turn signal to China that the United States has malign motives. Should China then feel less secure, it will be more likely to adopt competitive policies that the United States will see as more threatening. The result would be a negative spiral driven not by the international situation the states actually faced but by their exaggerated insecurities.
Moreover, states have often overestimated their insecurity by failing to appreciate the extent to which military capabilities favored defense. Before World War I, Germany exaggerated the ease of invasion and therefore believed that Russia's growing power threatened its survival. As a result, Germany launched an unnecessary preventive war. During the Cold War, the United States exaggerated the nuclear threat posed by the Soviet Union, failing to appreciate that large improvements in Soviet forces left the key aspect of the American deterrent -- a massive retaliatory capability -- entirely intact. This did not lead to war, thankfully, but it did increase the risks of one and led to much unnecessary tension and expenditure. Washington will have to guard against making similar errors down the road as China's conventional and nuclear forces grow and as clashes over secondary issues strain relations.
There has been no U.S. overreaction to the growth in China's military capabilities yet, but the potential for one certainly exists. The current U.S. National Security Strategy, for example, calls for the United States to maintain its conventional military superiority, but it does not spell out why this superiority is required or what forces and capabilities this requires. For the foreseeable future, China will lack power-projection capabilities comparable to those of the United States, but its military buildup is already reducing the United States' ability to fight along China's periphery. This will soon raise questions such as precisely why the United States requires across-the-board conventional superiority, what specific missions the U.S. military will be unable to perform without it, and how much the inability to execute those missions would damage U.S. security. Without clear answers, the United States may well overestimate the implications of China's growing military forces.
The danger of an exaggerated security threat is even greater in the nuclear realm. The Obama administration's 2010 Nuclear Posture Review holds that "the United States and China's Asian neighbors remain concerned about China's current military modernization efforts, including its qualitative and quantitative modernization of its nuclear arsenal." The NPR, however, does not identify just what danger China's military modernization poses. There is no prospect that any conceivable nuclear modernization in the foreseeable future will enable China to destroy the bulk of U.S. nuclear forces and undermine the United States' ability to retaliate massively. The most such modernization might do is eliminate a significant U.S. nuclear advantage by providing China with a larger and more survivable force, thereby reducing the United States' ability to credibly threaten China with nuclear escalation during a severe crisis.
The NPR says that the United States "must continue to maintain stable strategic relationships with Russia and China," but China has always lacked the type of force that would provide stability according to U.S. standards. If the United States decides that its security requires preserving its nuclear advantage vis-à-vis China, it will have to invest in capabilities dedicated to destroying China's new nuclear forces. Such an effort would be in line with the United States' Cold War nuclear strategy, which placed great importance on being able to destroy Soviet nuclear forces. This kind of arms race would be even more unnecessary now than it was then. The United States can retain formidable deterrent capabilities even if China modernizes its arsenal, and a competitive nuclear policy could well decrease U.S. security by signaling to China that the United States is hostile, thereby increasing Chinese insecurity and damaging U.S.-Chinese relations.
There is no question that China's conventional and nuclear buildups will reduce some U.S. capabilities that Washington would prefer to retain. But the United States should not rush to impute malign motives to those buildups and should instead be sensitive to the possibility that they simply reflect China's legitimate desire for security. When Donald Rumsfeld was U.S. secretary of defense, he said, apropos of China's increased defense spending, that "since no nation threatens China, one must wonder: Why this growing investment? Why these continuing large and expanding arms purchases?" The answer should have been obvious. If China were able to operate carrier battle groups near the U.S. coast and attack the U.S. homeland with long-range bombers, Washington would naturally want the ability to blunt such capabilities, and if the United States had a strategic nuclear force as vulnerable and comparatively small as China's (now somewhere between a tenth and a hundredth the size of the U.S. force), it would try to catch up as quickly as it had the resources to do so. Those actions would not have been driven by any nefarious plan to subjugate the world, and so far there are strong reasons to believe that the same holds true for China's course.
In sum, China's rise can be peaceful, but this outcome is far from guaranteed. Contrary to the standard realist argument, the basic pressures generated by the international system will not force the United States and China into conflict. Nuclear weapons, separation by the Pacific Ocean, and political relations that are currently relatively good should enable both countries to maintain high levels of security and avoid military policies that severely strain their relationship. The United States' need to protect its allies in Northeast Asia complicates matters somewhat, but there are strong grounds for believing that Washington can credibly extend its deterrent to Japan and South Korea, its most important regional partners. The challenge for the United States will come in making adjustments to its policies in situations in which less-than-vital interests (such as Taiwan) might cause problems and in making sure it does not exaggerate the risks posed by China's growing power and military capabilities.