The unexpectedly upbeat tenor of the Korean summit meeting is prompting analysts to consider the possibility of unexpected strategic challenges for the United States in East Asia. Although it seems unlikely that either a comfortable peace settlement or swift reunification of the two Koreas is in the cards, the prospect of detente on the peninsula in itself would be a change of major proportions. For five decades, the prospect of war in Korea and the threat the North posed have served as cornerstones on which US Asia military policy was built. The need to deal with this perceived threat outlasted Sino-American rapprochement, the end of the Cold War, and the demise of the bipolar Soviet-American rivalry. Indeed, the dangers that North Korea continued to represent some four decades after the end of the Korean War became the key to important elements of US strategic policy in post-Cold War East Asia, including the revision of the US-Japan alliance, the determination that the US would seek the early deployment of theater and national ballistic missile defenses, and the belief that engagement with China was strategically as well as economically wise because Beijing could help manage tensions and proliferation risks on the Korean peninsula. If the recent summit is a precursor to detente breaking out in Korea, it seems reasonable to believe that jiggling this strategic cornerstone will have important effects on the Asian strategic landscape.

Although one might be tempted to think of German reunification and the end of the Cold War in Europe as a logical comparison to an unfolding rapprochement in Korea, neither detente nor possible unification in Korea are likely to have similarly benign consequences for American interests. On the contrary, it is suggested below that the end of the “Korean contingency,” though welcome for many obvious reasons, will also greatly complicate security policy in Asia because it will eliminate what had been a convenient opportunity for the US to embrace “dual-use” policies. By this, I refer to measures that are explicitly justified on the basis of immediate needs arising from concerns about Korea, but that also serve as a hedge against implicit concerns about the long-term challenges some believe a more powerful China may pose. The fading of the Korean contingency will clarify strategic purposes and choices in ways that raise difficult problems for East Asian security, especially insofar as it seems likely to aggravate China’s foreign relations with the US and its allies. Below, I consider the possible consequences in just two important issue areas — the US military role in Northeast Asia and plans for deploying missile defenses.

The U.S. Military Role in Northeast Asia

Although the half-century military standoff on the peninsula made Korea a dangerous flashpoint in Asia, the status quo has in recent years also served as a lubricant somewhat easing the friction that emerged in China’s post-Cold War relations with other major states. Despite the collapse of the Soviet threat, the persistence of the Korean contingency enabled the US to justify concentrating the lion’s share of its 100,000-strong regional deployment in Northeast Asia and especially to explain the need to update its security treaty with Japan. Policymakers in Washington and Tokyo had become worried that stringent limits on Japan’s logistical support for US military action on the peninsula, while technically defensible based on the existing terms of the security treaty, would be politically indefensible and could jeopardize American support for the alliance. Thus, although Beijing openly worried that the real motivation for the changes was a trumped up China threat, the overriding reason for initiating the revision of the US-Japan security relationship was in fact growing concern about the possibility of renewed conflict in Korea and a desire to avoid the “checkbook diplomacy” to which Japan had limited itself during the Gulf War. Original intentions notwithstanding, however, China’s concerns were not fanciful. As the US-Japanese negotiations about the revised guidelines proceeded during the mid-1990s, rising tensions in the Taiwan Strait effectively broadened the implications of new language about allied cooperation to deal with instability that might develop in “surrounding areas of the Far East.” With the new guidelines announced in the wake of the 1995–1996 Taiwan Strait confrontation, and with Japan subsequently refusing decisively to foreclose its options by geographically circumscribing acceptable theaters of operation, China correctly noted that the new guidelines might be understood to apply to Taiwan and not just Korea. Yet, as long as the Korean contingency remained the top planning priority for US forces in Northeast Asia, China, Japan, and the US were able to uneasily paper over their differences of interpretation: Tokyo and Washington formally adhered to their “one-China” positions on the Taiwan dispute while Beijing largely limited its reaction to cautionary rhetoric about the folly of attempting to contain a nonexistent China threat. Realities on the Korean peninsula, in short, provided the US and Japan with a convenient and reasonably convincing counter to China’s allegations about the broader purposes of their new security guidelines. Rapprochement on the Korean peninsula will eliminate this line of argument and require the US and its allies, including Japan, to offer new justifications for their post-Cold War military postures.

The initial focus, however will not be on Japan, but on the future of US forces in Korea itself. As many have noted, the long-standing reason for more than 35,000 US troops stationed and training in Korea will evaporate once the South no longer fears attack from the North. Under such transformed circumstances it will also be hard to argue that the large American deployment in Korea is essential to the broader US goal of preserving East Asian peace and stability. Given its proximity to the even larger US deployment in Japan, how much military value do the American forces on the Korean peninsula add? US interests in East Asian peace and stability would seem to be adequately served by its major presence in Japan complemented by solid US treaty ties not just with Korea, but also with other allies to the south (Australia, the Philippines, Thailand) and agreements that have improved US military (especially naval) access in other states throughout the region. What distinctive purpose would be served by continuing to maintain the concentration of US forces in Korea? Absent the North Korean threat, the obvious answer will have to be that there is some other potential threat to the peninsula serious enough to require this hedge. In a post-Soviet world, the only logical candidate will be China.

Peace on the peninsula would not only require a new rationale for continuing the major US presence there in ways that entail an uncomfortable clarification of US concerns about China, it will likely have a similar effect on the updated US-Japan alliance. Bilateral alliances are healthiest when a common adversary provides the rationale for joint planning and burden sharing. During the Cold War, few in Japan (other than an ever-shrinking leftist minority) had qualms about viewing the Soviet Union as the principal adversary against which they were allied with the US. After the Cold War, North Korea served as both the new principal adversary and also as a politically palatable proxy for maintaining the health of a military alliance that could also be relevant for dealing with other future threats that are now left unspecified. But if Korean reconciliation robs the alliance of its presently useful unifying foe, debate about the central purpose of the most important American bilateral relationship in Asia seems inevitable. Can Washington and Tokyo sustain the present healthy security ties simply by advocating a shared interest in “peace and stability?” Probably. Can such a debate unfold without questions about what threats to peace and stability could arise that require the joint action of the world’s two most powerful advanced industrial states? Probably not. China’s easily anticipated concern that it is the unstated threat informing Japanese-American planning will complicate the already delicate relationship between Beijing and each of the allies. And Japan’s sensitivity to China’s reaction, as well as the lack of a domestic political consensus about “the China threat” (unlike the erstwhile Soviet and North Korean threats), will also pose new challenges for sustaining cooperation between Tokyo and Washington.

Missile Defenses

In the immediate aftermath of the Soviet collapse, Pentagon planners lamented the lack of enemies to justify military modernization — in the words of one US Secretary of Defense, they were down to the likes of Cuba and North Korea. As it turned out, the Pentagon’s concerns were overdrawn. North Korea played the role of enemy better than anyone could have expected. Despite their country’s severe domestic weaknesses in the 1990s, the Pyongyang regime dedicated itself to developing a ballistic missile and nuclear weapons capability that quickly alarmed the US and its allies in East Asia. Emerging on the heels of the SCUD vs. Patriot experience in the Gulf War, North Korea’s efforts provided an unexpected but decisive boost to the revived American argument in favor of deploying ballistic missile defenses. Moreover, it provided just the right sort of boost — justification for deploying a limited defense that could deal with the primitive, small-scale arsenals of “rogue states” (now renamed “states of concern”), but not one effective enough to degrade the retaliatory capability of major powers. An array of critics (arms control experts, some US allies, and the Russians and Chinese) questioned the legality, feasibility, and desirability of the proposed TMD and NMD systems. But North Korea had proved to be an excellent salesman for missile defenses. Recurrent suspicious behavior at alleged nuclear weapons development sites punctuated by missile tests that were just successful enough to arouse strong concern that Pyongyang might one day get it right, helped build momentum in the US for plans to deploy national and theater missile defenses as soon as was possible. In the course of the 1990s, the North’s opaque nuclear program and its all too transparent ballistic missile tests also nurtured support within Japan for cooperation with the US on TMD development, overwhelming earlier reluctance based not just on the effort’s high cost but also worries about China’s clearly expressed objections. Beijing consistently rejected the argument that the Americans and Japanese were actually going to incur the expense of missile defenses just to deal with the strategically puny North Koreans. It viewed limited TMD and NMD as merely a first step towards a larger program designed to neutralize China’s missile arsenal, the outgunned PRC’s only military ace in the hole.

Nevertheless, although China did not hesitate to make its point about missile defenses, as long as Pyongyang’s opaque capabilities and intentions worried others, Beijing, Washington, and Tokyo could at least argue about the scope and purpose of the allies’ plans. Should the North Korean missile threat subside, the rationale for NMD, and especially TMD, will have to change. The North’s late 1999 promise not to test more long-range missiles, its deft handling of the inter-Korean summit, followed by its announced moratorium on further missile testing have set in motion forces that will become stronger if peace actually takes root on the peninsula. American supporters of NMD may be able to point to “states of concern” beyond North Korea that justify deployment. Not so America’s Northeast Asian allies. In particular, the end of a pressing North Korean missile threat will shake the recently formed Japanese consensus about shouldering its share of the economic burden and tolerating the diplomatic friction with China that cooperation with the US on TMD entails. Although Tokyo may well decide that the health of the alliance requires it to live up to its current TMD commitment, supporters of this position will find it a tougher sell without the looming fear of improved Taepo Dongs crossing the Sea of Japan. The idea of redefining the purpose of TMD as a counter to a potential China threat is almost certainly a non-starter in Japan (and is also unlikely to find strong support in Seoul). More likely, without the unifying immediacy of the North Korean threat, the sort of ambivalence that prevails in Southeast Asia about cooperating with the US in strategic ventures that implicitly target China (like TMD) will spread to Northeast Asia as well. Yet the US might reasonably argue that TMD is essential protection for American forces and their dependents if they are to be put in harm’s way by regional alliance commitments. What happens if the US interest in protecting its personnel clashes with its ally’s interest in maintaining good relations with China? The question suggests the sort of hard spadework that will have to be done to prevent TMD from becoming a deeply divisive matter for the US and its staunchest Northeast Asian ally if peace breaks out in Korea. The task will be especially daunting since the US interests are mixed, too. As long as Washington values its working relationship with China, it will not be easy to undertake military initiatives that amount to dealing with it as an enemy. Diplomatic legerdemain to reassure Beijing about the purposes of TMD may be attempted, but as with reassurances to Moscow about the benign nature of NATO’s eastward expansion, such efforts are unlikely to convince even the least suspicious leaders in China.

The complications of Korean detente for US missile defense policy could be even more far-reaching than just suggested. If a clear China focus means that Japanese (and Korean) support for TMD wanes while American support remains strong, the only soulmate for the US on this issue in east Asia may be Taiwan. How would an American government (especially its congressional wing) respond to a situation in which others balk at participation in US missile defense deployments, while Taiwan becomes a eager suitor? The answer almost certainly depends on the overall state of Sino-American and cross-strait relations at the time. But the potentially serious consequences of a US decision to cooperate with Taiwan on missile defense are clear and arise from conflicting Sino-American perceptions about what this decision would signify. Americans, with Taipei’s supporters in Congress taking the lead, would likely see cooperation with Taiwan on TMD as a logical and appropriate response to the growing Chinese missile capability across the Taiwan Strait, a response consistent with the spirit of the Taiwan Relations Act of 1979. In contrast, China would likely see such cooperation as a direct challenge to its national interests, one that defied the spirit of a series of Sino- American executive understandings, solidified the currently informal military ties between Taipei and Washington, reduced Taiwan’s willingness to negotiate a reconciliation, and perhaps emboldened those on the island who would prefer to move toward independence. Thus, unlike present TMD plans in which one can at least envision a strategic architecture that would be focused on North Korea, but could be reoriented and even relocated to other parts of the Far East, TMD based on or around Taiwan promises the near certainty of a major Sino-American crisis.

Ripple effects from Korean detente for the larger US interest in missile defenses may be felt as well. If TMD is deprived of its Korean rationale, the Russian willingness to explore a compromise that includes its suggested boost-phase defense ringing the peninsula will lose its appeal, at least in East Asia. In that case, any possibility of Russia serving as an intermediary to win Beijing’s acceptance for a very limited missile defense plan would be gone. An American decision to move forward with TMD and NMD over Russian and Chinese objections will then entail greater risks, including the risk of closer Sino-Russian cooperation on defense-defying strategic missile technologies.

The central thread running through these projected effects of detente in Korea is the way it may reshape the East Asian strategic landscape by forcing actors to rethink their common and conflicting interests, especially when it comes to the future of relations with China. Korean detente would, in fact, be the third major shock of this sort since the late 1980s. China’s heavy-handed suppression of domestic political dissent in June 1989 was the first shock, tarnishing the PRC’s generally positive image in the West and shaking the self-confidence of the leaders in Beijing about the benign nature of the international setting in which they hoped to pursue national modernization. Shortly afterward, the end of the Cold War and the collapse of the Soviet Union provided a second, arguably more important shock, decisively undermining the earlier willingness of China and its strategic partners to overlook many bilateral differences for the sake of preserving their counter-Soviet alignment. These first two shocks made for an uneasy period of adjustment in China’s foreign relations during the early post-Cold War years. Peace in Korea promises to administer yet another shock. Even if its effects are less dramatic than those of the first two and, one can hope, less dire than the sort depicted above, it is certain to be an event that will require policy adjustments from all concerned about East Asian security. Among the many challenges a Korean peace would pose, three stand out: (1) US defense planners, long focused on the Korean peninsula as the major contingency in East Asia, will have to adopt a more genuinely regional rather than subregional focus; (2) The US-Japan alliance, having recently adjusted to the collapse of the Soviet threat in Asia, will face new pressures to redefine its purpose; and (3) The US will have to decide how explicit and vigorous a role it wants to play in counterbalancing China.