A US Perspective

"Missile Defense on the Korean Peninsula"

From Political Taboo to Strategic Hedge: A US Perspective on Ballistic Missile Defense

Ballistic missile defense (BMD) is both expensive and largely unproven;¹ so on what basis might we judge its value? This article offers a US perspective about the utility of BMD in support of Korean security. At the regional level, it is a logical hedge in a modern security environment filled with long-range precision weapons. On the Korean Peninsula, it is a responsible counter against the growth and consolidation of North Korea’s nuclear weapons and missile programs. And within the US-ROK alliance, it increases the likelihood of US commitment to the ROK in the event of a crisis or conflict on the peninsula. Beyond these rational, material incentives to pursue BMD in the ROK, there is also an overwhelming ideational consideration: in light of Chinese warnings against pursuing certain types of BMD, officials in the United States and around the region may view ROK decisions about BMD as a leading indicator of loyalty in a long-term strategic competition between China and the United States. In this way, BMD in Korea is about far more than Korea.

BMD and the Future of War

Missiles are a reality of modern warfare. The spread of cruise missiles, ballistic missiles, and unmanned aerial vehicles (UAVs) of various types enables militaries of any size or sophistication to strike others lethally, rapidly, with precision, and from great distances.² Because much of the technology involved in these “guided munitions” is available commercially, barriers to acquisition and employment are low. Technologies like these give actors with malign intentions an unprecedented ability to do harm; in the hands of militaries, they can be tools not just of violence but of coercion that extract political demands from adversaries. In the 1970s, only the United States possessed the ability to strike quickly with long-range guided munitions because of the complex of supporting technologies it required: computing power, lasers, GPS technology, satellite communications, and long-range rockets.³ Today, each of these components exists in the private sector, and the weapons they support—ballistic missiles, cruise missiles, and UAVs—are part of the arsenals of every advanced military, including South Korea’s.

A security environment in which one’s neighbors deploy guided munitions of various types is an environment that should logically favor offensive rather than defensive action in the sense that guided munitions make rapid, calibrated violence easier than at any point in military history.⁴ In this environment, BMD is one of very few military tools that help restore a balance between offense and defense because it is one of very few tools capable of countering guided munitions.

Whatever South Korea’s assessment of its security interests today, its geopolitical history is one of repeated invasion and victimization, and its contemporary security environment is one where all of its neighbors possess guided munitions. Overwhelming near-term concerns about North Korea tend to dominate South Korean security calculations, but longer-term geopolitical disputes potentially remain just over the horizon. In the modern era, China has laid scholarly claim to historical Koguryo, a northern portion of the Korean Peninsula.⁵ Even more recently, China’s air defense identification zone has impinged on South Korean airspace.⁶ Russia, long passive in Asian affairs, has rekindled a political and economic relationship with North Korea, with hints of a military dimension as well. And Japan, constrained by both a pacifist constitution and a shared alliance with the United States, is in the process of separating itself from its pacifist identity; its military is the most technologically advanced in the region, and it refuses to abandon its claims to the island territory South Korea occupies and claims as Dokdo.⁸

None of these circumstances constitute cause for alarm, and none threaten South Korea today. But collectively and individually, they reveal to South Korea a real basis for disputes with neighboring states, who happen to possess multiple types of guided munitions, and some of whom are already developing next-generation hypersonic missiles.⁹ In future diplomatic contexts, does South Korea prefer to engage and negotiate with others knowing it is wholly vulnerable to their military arsenals? Or will South Korea feel more comfortable dealing with neighboring powers with a narrower military gap between them? BMD is a measure to narrow that gap without being inherently antagonistic toward others.

Countering North Korea’s Asymmetric Capabilities

For all the latent potential of regional security dynamics to threaten South Korean interests, it is North Korea’s conventional, nuclear, and asymmetric capabilities that South Korea’s military judges the most immediate threat, according to its annual Defense White Paper.¹⁰ North Korea’s conventional military power is large but eroding due to maintenance, training, and lifecycle challenges.¹¹ Over the last decade, however, North Korea has signaled several shifts toward an asymmetric posture designed to impose costs on or extract political concessions from South Korea and the United States through unconventional means. At lower levels of friction these unconventional means have taken the form of drones, cyberattacks, and other forms of “gray zone” coercion.¹² These actions to date have not included nuclear weapons or missile attacks of any kind, but they have taken place in the shadow of North Korea’s advancing nuclear and ballistic missile programs.

Because North Korea’s nuclear and missile capabilities have been allowed to modernize and grow unchecked for much of the last 15 years, South Korea increasingly finds itself in a position where North Korea’s capacity for violence outpaces South Korea’s ability to defend against it. It is not simply that for each novel form of North Korean provocation South Korea must develop an operational counter; this is an unfortunate reality of the strategic situation but not the principal problem. Instead, the problem is that South Korea remains vulnerable to ballistic and cruise missiles, whether nuclear or conventionally armed, and as those capabilities advance the vulnerability grows. As North Korea invests in nuclear warhead miniaturization and diversifies the delivery vehicles it has for nuclear payloads, it is also increasing the size of its arsenal—as many as 16 nuclear weapons today and possibly dozens more by 2020.¹³

North Korea has an offensively oriented military posture, and by its own rhetoric purports to have a “seven-day” asymmetric military campaign plan against South Korea.¹⁴ It is reasonable to expect that North Korea sees its missiles—conventionally armed or nuclear tipped—as part of such a posture and plan. It, thus, has the capability and an expressed intent to conduct strikes against the South under certain conditions. Rather than constituting a static threat, however, South Korea’s vulnerability to North Korea’s nuclear and missile programs grows as the capability improves. Absent an unforeseeable diplomatic breakthrough, there are only two operational counters available to South Korea to mitigate its vulnerability to ballistic and cruise missiles: preventive strikes against known and suspected missile sites and BMD. Of the two, the latter logically poses less risk of inadvertent escalation than the former, intercepting North Korean missiles only after launch, typically during the descent into “terminal phase” when a missile is near to detonating against a South Korean target. As long as North Korea’s nuclear and missile programs continue without external constraint, BMD remains a crucial source of threat mitigation, even though North Korea’s missile inventory will exceed South Korea’s BMD capacity for the foreseeable future.

Preventing Alliance Abandonment

In recent debates about whether the United States should deploy the Terminal High-Altitude Air Defense (THAAD) system to South Korea,¹⁵ the scope of discussion has completely excluded the connection between improved US security and strengthened US commitment to South Korea. North Korea has made clear in word and deed that it intends to become capable of striking US targets with long-range ballistic missiles.¹⁶ To the extent that South Korea feels trapped between the fears of ally abandonment and entrapment, a common dilemma in alliances,¹⁷ it should be concerned that future risk-averse US policymakers might be deterred from taking actions against North Korea if there is a risk of retaliation against US territory. US abandonment today is unfathomable, but as North Korea improves the range and precision of nuclear-capable ballistic missiles, future risk of abandonment may increase.

THAAD, the most advanced missile defense system in the US arsenal, stimulated much controversy in Korea after former USFK Commander, General James Thurman, stated publicly that the United States should deploy the system to South Korea.¹⁸ While THAAD may offer South Korea some improved protection against incoming missiles and much greater radar coverage, its greatest protective value is in the added security it offers the United States against North Korean missiles. A robust missile defense architecture in Asia that protects the United States and its allies from North Korean missiles will allow US policymakers greater latitude in crafting policy and holding steadfast to Korean security commitments. But to the extent the United States is vulnerable to either first strikes or retaliation coming from North Korea, US options will be conditioned by the prospect of the costs such strikes would impose. BMD systems like THAAD could help minimize the negative impact North Korea’s missile program could potentially have on US long-term commitments. US policymakers today are committed to Korean security, but we cannot know the risk propensity of future policymakers. US vulnerability to missile strikes should be seen from the Korean perspective as an undesirable structural pressure on future US decision-making. Sound strategic decisions are those that alleviate future structural pressures or expand future decision-making possibilities; vulnerabilities typically have the opposite effect, and advanced BMD can help minimize vulnerability to missiles.

Sino-US Strategic Competition

The aforementioned merits of BMD on the Korean Peninsula are all military or narrow national security considerations, but the meaning that policymakers in the United States, China, and the rest of the region assign to BMD is also political. When China’s defense minister, Chang Wanquan, met with South Korean defense minister, Han Min-Koo, and warned South Korea against allowing the introduction of THAAD into the Korean Peninsula, China made BMD in Korea strategically significant in the context of the Asian security order and Sino-US competition.¹⁹

China has begun not simply resisting, but actively undermining certain elements of the international order that have existed since World War II, in direct contravention of US preferences.²⁰ China seeks resolution of territorial disputes through bilateral rather than multilateral adjudication.²¹ It has undercut the World Bank and Asian Development Bank by offering the region an alternative for infrastructure loans.²² And it has called for an end to “Cold War era alliances” in favor of an “Asia for Asians,” implying a region without the United States.²³ Whether Chinese preferences for regional order are more beneficial to middle powers is debatable, but less debatable is China’s willingness to challenge US preferences along each of these major dimensions of order. That big picture conflict of interests puts the United States and China in a long-term competition for regional influence regardless of amity or cooperation that may exist in other aspects of the bilateral relationship.

China has decided to imbue South Korea’s BMD decisions regarding THAAD and a “regional missile defense architecture” with high political salience, explicitly assigning meaning to it in zero-sum terms relative to the United States. Yet, any argument that China is threatened by BMD—putting aside that such an argument requires interpreting a defensive capability as an offensive one—is difficult to reconcile with its relative silence about South Korea’s offensive cruise missile development, which may be able to reach Beijing depending on geographical placement.²⁴ If news reports on the subject are true, China has counseled South Korea that it will judge the latter’s BMD decisions through a competitive loyalty lens relative to the United States.²⁵

Sociologists have explained that individuals can carry multiple identities simultaneously, and even adhere to sometimes contradictory sets of norms, which create cross-pressures on decision-making.²⁶ So it is with relations among states. China’s security preferences on BMD in Asia contradict those of the United States. Such cross-pressures help make sense of why there is a controversy about BMD in South Korea in the first place. South Korean foreign policy decisions take place in a web of multiple, sometimes competing relationship considerations, and it cannot weigh the costs and benefits of policy decisions apart from that web of relationships. But while South Korea must maintain political relations with both China and the United States, that does not mean it must take an equidistant position between the two; on security matters, the United States is South Korea’s guarantor while China is a historical invader (daenoam). Although from the US perspective BMD is principally about North Korea, China has chosen to frame it differently, applying political pressure to South Korea not to respect the logical preferences of its other relationships. Only South Korea can decide how it will judge the importance of BMD, but as it does so it should be aware that outside powers—especially China—view it as an indicator of where the region might be headed.

Principle, Not Panacea

BMD is not a cure-all for managing Korea’s security environment, and technology cannot be a permanent solution to problems that are fundamentally political. Even if South Korea chose to frame BMD decisions narrowly in terms of a net assessment of the local military balance, and even if it maximally invested in maintaining a large BMD inventory with cutting-edge technology, its BMD capabilities would still not be sufficient to offset North Korea’s missile capabilities, and that offense-defense gap is on a trajectory to worsen with time.

But these are not reasons to avoid BMD, and whatever reservations might exist in South Korea about BMD, it cannot logically be an all or nothing issue but rather one of degree—South Korea already owns a modest BMD capability. Under progressive governments in South Korea, BMD took on a taboo meaning, and subsequently the ROK initially showed a degree of deference to China’s vocal concerns, though that may be changing due to Beijing’s heavy-handedness. But military-technical trends in Korea’s regional security environment make BMD more salient than in the past. North Korea’s capabilities, intentions, and force posture place growing emphasis on ballistic missiles, cruise missiles, and UAVs. BMD’s ability to offer protections for the United States helps long-term alliance credibility. And in abstract debates about the future of the Asian security order, Korean BMD decisions have become an indicator of US versus Chinese centrality in Asia. While no substitute for either strategy or diplomacy, from the US view, BMD is an increasingly important complement to a larger South Korean and alliance security hedge.

Dr. Van Jackson is a Visiting Fellow at the Center for a New American Security and Council on Foreign Relations International Affairs Fellow. The views expressed are his own.