Military Strategy Magazine  /  Volume 1, Issue 1  /  

Lynchpin: The U.S.-ROK Alliance after the Cheonan

Lynchpin: The U.S.-ROK Alliance after the Cheonan Lynchpin: The U.S.-ROK Alliance after the Cheonan
To cite this article: Denmark, Abraham M. and Hosford, Zachary M. “Lynchpin: The U.S.-ROK Alliance after the Cheonan.” Infinity Journal, Issue No. 1, Winter 2010, pages 18-21.

In the dark waters of the Yellow Sea on March 26, 2010, the South Korean corvette Cheonan was suddenly struck by a torpedo, broken in half, and sunk in 5 minutes – claiming the lives of 46 South Korean sailors. A subsequent international investigation identified a North Korean mini-submarine as the source of the attack.[i] Relations between the Republic of Korea (ROK) and Democratic People’s Republic of North Korea (DPRK) – the formal names of South and North Korea – took an immediate nosedive, as did South Korea’s relations with China after Beijing refused to acknowledge Pyongyang’s responsibility for the attack.

Yet if there is any silver lining to this tragedy, it is that it inaugurated a deeper era of the U.S.-ROK alliance. Nearly four months after the sinking, the ROK and U.S. militaries conducted major naval exercises in the waters around the Korean peninsula. Washington strongly supported Seoul’s diplomatic efforts in the months following the sinking, and in June, the American and South Korean presidents jointly announced a delay in the transfer of wartime operational control (OPCON) from 2012 to 2015 – a major diplomatic achievement for Seoul. The Secretaries of State and Defense visited Korea to commemorate the 60th anniversary of the start of the Korean War. During the same trip, they also held a historic “2+2” meeting with their ROK counterparts which approved a broad swath of initiatives referred to as “Strategic Alliance 2015” (SA2015). While much of these events would probably have occurred without the sinking of the Cheonan, the tragedy added a degree of focus, attention, and urgency that was needed to truly begin a new era in the alliance.

Still, significant challenges remain. Seoul is conducting a major reevaluation of its defense reform plan, which will inevitably be complicated by South Korea’s vigorous domestic political debates. Seoul is also facing the daunting challenges of both managing China’s rise as well as the continued threat coming from North Korea. At the same time, the American strategic community is grappling with the U.S. military’s long-term ability to unilaterally provide global public goods in the face of new rising powers and proliferating advanced military technologies.[ii]

The consequences for the United States, and the broader Asia-Pacific region, will be profound. East Asia is poised to become the global economic engine of the 21st century, and this prosperity will be contingent on the stability traditionally provided by the United States and its allies and partners. Yet as China’s power increases and North Korea continues to threaten the region, American policymakers are beginning to look to South Korea as a lynchpin for American presence in the region. Since President Obama’s inauguration, his administration has clearly established Asia as a top foreign policy priority. The U.S.-ROK alliance will play an increasingly vital role in America’s approach to the region, and it will be incumbent upon both Washington and Seoul to build on the strong foundation of the past, and chart a path forward for a flexible and robust alliance.

The United States Returns to the Asia-Pacific

Since his inauguration, President Obama has signaled that the Asia-Pacific region will be a top priority for his administration. After declaring himself America’s “first Pacific President,” he made two trips to the region in two years. Secretary of State Hillary Clinton visited the region six times in the same time span. By the end of his November 2010 trip to Asia, President Obama and Chinese President Hu Jintao will have met 7 times in Obama’s first two years – more than any other American and Chinese heads of state for the same amount of time.[iii] President Obama’s first head of government visitor was Japanese Prime Minister Taro Aso, and his first head of state visitor was Indian Prime Minister Manmohan Singh.

Since Obama’s inauguration, the U.S. has also upgraded its relations with non-allies throughout the region and increased the level of its participation in the region’s multilateral fora. President Obama’s historic visits to India and Indonesia signaled a stronger interest in building ties in South and Southeast Asia, as did the warming ties between Washington and Hanoi. Washington also designated the East Asia Summit (EAS) as the region’s preeminent security/strategic organization, and the President has committed to attending its annual leaders summit.

Seoul’s Renewed Focus

Throughout America’s rapprochement with the Asia-Pacific region, South Korea’s international stature has steadily increased. Serving as the host of the November G-20 summit finalized Seoul’s ascent as an important international political player. American policymakers also highlighted South Korea’s increasing importance to American interests, referring to the ROK as “a lynchpin of stability and security in the region and now even far beyond.”

This rising stature coincided with a strategic refocusing within Seoul’s national security community on the North Korean threat. Despite the heavily-fortified 238-kilometer border and history of belligerence serving as a constant reminder of hostilities, North Korea’s sinking of the Cheonan catalyzed a significant shift in Seoul’s strategic thinking. South Korea’s cabinet endorsed a significant shift in the ROK’s defensive posture, spending 35.2 billion won ($29 million) to procure and maintain weapons systems to upgrade warship sonar, deploy sound surveillance systems for islands near the sea border, and develop an indigenous three-dimensional radar system. The ROK military has also announced plans to buy minesweeper and anti-submarine helicopters.[v]

Yet these adjustments – though welcome and helpful – will only be the first step in Seoul’s attempts to deal with a complex set of threats posed by the DPRK. From hundreds of thousands of special forces to SCUD ballistic missiles, to biological and chemical weapons, to an array of artillery that could quickly devastate Seoul, to nuclear weapons, the North Korean military poses a significant threat. Moreover, the potential for unconventional threats, such as the destruction of up-river dams to flood the South among others, presents a significant challenge to the South Korean people. South Korea has never been more cognizant of these threats as it is now, which has been further complicated by the power transition occurring in Pyongyang.

Though long predicted and not yet realized, many analysts in South Korea and the United States see the Kim family regime as increasingly brittle.[vi] With Kim Jong-il reportedly suffering from a wide variety of serious ailments and attempting to establish his young son Kim Jong-un as successor, many see the coming months and years as especially trying for the DPRK’s ruling regime. The younger Kim might lack legitimacy and authority, something his father never seemed to confront when he took power from his own father and founder of the country, Kim Il-sung.

Kim Jong-un’s inexperience will make consolidating power difficult. Such a situation may spell the end of the era of one-man rule in North Korea, portending a time in Pyongyang when political dynamics will be more complex and possibly more unpredictable. If Kim Jong-un cannot consolidate power, the regime could collapse, potentially prompting a major humanitarian intervention as the world would have to help feed, medicate, and rebuild a society of more than 22 million that has faced poverty and near-starvation for decades.[vii]

The implications of regime collapse in the DPRK are tremendous – a fact South Korea fully appreciates. If the government were to topple, the effects would likely be wide-ranging and severe, even if a new government were able to regain power. Not only would the North Korean population likely suffer from further reductions in food distribution and basic services, the shock to the tenuous region could cause chaos. Among the numerous challenges that such a scenario would create would be the potential for unprotected nuclear and other WMD materials and weapons, large refugee flows northward into China and across the DMZ into South Korea, a catastrophic humanitarian crisis stemming from the loss of services and food production, and unprecedented financial costs to address these and other challenges.

Though a North Korean collapse would not necessarily lead to the unification of the peninsula, there would be tremendous pressure to reunite the two countries in such a scenario. The majority of South Koreans would like to see a unified Korea – though the tremendous costs involved would rightly give them pause. Some analysts have placed the cost estimates of reunification to be between $25 billion and $3.25 trillion, not including the cultural and social costs of reintegrating the two societies, making unification a truly multi-generational challenge.[viii]

The Next Evolution in the Alliance

In the context of South Korea’s refocusing on North Korean threats and major uncertainties—both new and old—several near-term events spanning the political, economic, and military arenas will have a profound effect on the U.S.-ROK alliance. How each country approaches these issues will have a significant impact on the trajectory of the alliance going forward. On the military front, plans for the transfer of wartime operational control and South Korea’s ongoing and oft-changing defense reforms are occurring in the midst of a reevaluation of the North Korean threat. If the United States and South Korea can fit these individual strands together in a strategic manner, both countries will advance not only their own security interests, but also the alliance as well.


Washington and Seoul agreed in 2004 to realign U.S. forces in the South in order to enhance the American military’s strategic flexibility, while transferring increased responsibility for the defense of the South to the ROK military. The centerpiece of this shift was the transfer of wartime operational control (OPCON) from the U.S. to the ROK military, which was originally scheduled to take place in 2012 but was recently postponed to December 2015.

Meanwhile, in mid-2005, South Korea’s Defense Ministry announced an ambitious plan to reform the ROK military, called “Defense Reform 2020.” The objective of the plan was to qualitatively improve the military while reducing the quantity of military manpower and weapon systems by replacing out-dated weapons with high-technology systems and reducing the military’s overall troop strength.[ix] The drive to reduce troop strength stemmed in part from the recognition that South Korea’s changing demographics will pose a considerable challenge to its military manpower.[x]

The Defense Reform 2020 plan, however, has been plagued by problems since its inception. It called for military budget increases through 2020 at a total cost of 621 trillion won ($550 billion in 2010 dollars) over 15 years. By 2009, however, the plan had a 22 trillion won ($19 billion) shortfall. The Ministry of Strategy and Finance’s 2010 military budget revision increased the 15-year shortfall to about 42 trillion won, or $37 billion dollars. Some estimates now put the final shortfall by 2020 at about 110 trillion won ($97 billion)—almost four times the 2009 MND budget.[xi]

Moreover, the plan was conceived with a radically different understanding of South Korea’s strategic environment. The government in Seoul at the time under President Roh Moo-hyun sought engagement with North Korea, and had planned to significantly downsize the ROK military as part of a broader “Sunshine Policy.” The current government’s cognizance of the challenges posed by the DPRK requires a significantly different approach to defense planning, and a review of the Defense Policy Review is in order. Should North Korea collapse, securing it will require significant manpower, as well as a force that is experienced in the ways of peacekeeping, humanitarian assistance, and counter insurgency.

In these scenarios, the ROK military could potentially be called upon to conduct a wide variety of complex tasks that would often bear little resemblance to the defense of the South from Northern attack. For example, providing food and medicine to millions of malnourished North Koreans, many of whom could be hostile and well-armed, will require a unique set of skills and capabilities that more closely resembled peacekeeping and counter-insurgency than conventional defense against attack. If South Korea were to continue its international contributions to peacekeeping, stabilization and reconstruction efforts, it would likely be further prepared for such contingencies on the Peninsula.[xii]

Unfortunately, as seen above, South Korea does not have the budgetary (nor the demographic) ability to support a large military capable of doing all things. Considering this, the ROK military should identify its top priorities and develop capabilities that are the most applicable to the widest range of possible contingencies.

With the transfer of OPCON delayed from 2012 to 2015, Washington and Seoul have seized the opportunity to develop a plan to jointly deal with the complex challenges the ROK will face in the short-to-medium term in a program called Strategic Alliance 2015 (SA15). Part of this effort should be a robust effort to plan and exercise capabilities necessary for dealing with a wide variety of collapse and North Korean attack scenarios. Fundamental to the success of these plans will be the integration of non-military agencies and organizations, so economic reconstruction and governance can be as well coordinated as military maneuvers.

Moreover, both sides should also look to long-term strategic issues and begin to discuss principles and objectives for a unified Korean peninsula. Fundamental to this conversation will be a frank bilateral conversation about the post-unification purpose and role of the U.S.-ROK alliance, and the key interests and principles of both Washington and Seoul.


The ROK employs significant diplomatic and military power due, in part, to its own impressive economic rise. However, the United States has in recent years failed to recognize the strategic significance of trade in East Asia. As the region’s economies expand and grow ever-more interconnected, the United States has to date fallen behind regional trends. This has had strategic effects: South Korea’s top trading partner today is China, which is true for most other East Asian countries. This will inevitably have strategic effects in the years to come, especially if China continues to employ economic levers of influence and pressure to achieve strategic ends – as it did by withholding rare earth shipments to Japan during a row over disputed islands.

If the United States is to maintain strong relations throughout the Asia-Pacific region, those relations must be greater than military/strategic relations. Increased trade and economic integration will be essential. The most important and visible factor in the U.S.-ROK economic relationship is the signing and ratification of a free trade agreement, known as KORUS. The administrations of both President Lee and President Obama have been pushing for the passage of the trade pact, citing economic benefits for both parties, but it has come up against some opposition in both capitals. Both administrations should make it clear that the future strength of the alliance will in part ride on trade and economic integration. Korea expert and former NSC Director for Asia Dr. Victor Cha (disclosure: Dr. Cha is on the Board of Advisors for the authors’ home organization, the Center for a New American Security) has quipped that if the U.S. fails to ratify KORUS, historians will point to that moment as the time when the U.S. ceded Asia to China.[xiii] Dr. Cha’s analysis is more accurate than ever, and the time for the U.S. to sign and ratify KORUS is now.


Ultimately, South Korea enjoys a high degree of security, protected from attack by the U.S. extended nuclear deterrent and its 28,500 U.S. troops stationed on the peninsula. With mutual interests in stability and shared democratic values, the United States and South Korea both receive significant benefits from the relationship.

But as Washington and Seoul look to 2015 and beyond, defense reform must be an integral part of alliance reform. The United States will stand with its ally during times of crisis or conflict, but will increasingly look to its ally to substantially contribute to its own defense and to the maintenance of the international system. The ROK must therefore be prepared to accept the challenges that come, no matter their source or character.

Yet, despite the complex challenges both sides will face in the coming years, Washington and Seoul must look beyond military and security relations and chart an alliance that is truly strategic. This will mean closer economic relations, which must be based on a robust free trade agreement. Without close economic ties, U.S. relations with Korea will be fundamentally limited in both its scope as well as in its depth.

As a lynchpin of America’s interests in the Asia-Pacific region, South Korea must be prepared to step up to its natural role as a regional and global leader. The U.S.-ROK alliance must also be prepared to handle the region’s future challenges. With China rising and North Korea undergoing a historic transition, the time to build a strategic, robust, and effective alliance is now.


[i] “Joint Investigation Report on the Attack Against ROK Ship Cheonan,” Ministry of National Defense, Republic of Korea, September 2010,
[ii] Andrew Krepinevich, 7 Deadly Scenarios, New York, NY: Random House, January 2010; Abraham Denmark and James Mulvenon, Contested Commons: The Future of American Power in a Multipolar World, January 2010,
[iii] James S. Brady, “Press Gaggle on the President’s Upcoming Trip to Asia,” The White House: Office of the Press Secretary, October 28, 2010,
[iv] Hillary Clinton, “Speech on U.S. Agenda in Asia-Pacific Region,” U.S. Department of State, October 28, 2010,
[v] Jung Sung-ki, “Defense Reform 2020 to be revised for NK threat,” The Korea Times, May 26, 2010,
[vi] See Minxin Pei, “Get Ready for DPRK Collapse,” The Diplomat, May 12, 2010,; Robert D. Kaplan, “When North Korea Falls,” The Atlantic Monthly, October 2006,
[vii] See Robert Kaplan and Abraham Denmark, “Power transfer will shake North Korea,” Financial Times, September 7, 2010.
[viii] David Coghlan, “Prospects From Korean Reunification,” Strategic Studies Institute, April 2008, p. 3; and Samuel S. Kim, “The Mirage of a United Korea,” Far Eastern Economic Review, November 2006, p. 12.
[ix] For more details on the Defense Reform Plan, see Bruce W. Bennett, “A Brief Analysis of the Republic of Korea’s Defense Reform Plan,” RAND, 2006,
[x] In South Korea, military service is mandatory for males aged 18 to 35 and the ROK military is primarily manned by males at the age of 20. According to the Korean National Statistical Office, 20-year-old men generally numbered more than 400,000 from 1977 to 2003, which was quite sufficient to sustain the 690,000 active-duty military population that had been maintained in the 1990s. But the number of 20-year-old men in 2008 was projected to fall to 317,000, creating a serious manpower shortage. This number is projected to rebound up to 368,000 in 2013 and then decline nearly continuously, falling below 200,000 in 2036. Korean National Statistical Office, As cited in Bruce W. Bennett, “A Brief Analysis of the Republic of Korea’s Defense Reform Plan,” RAND, 2006,
[xi] Bruce Bennett, “Managing Catastrophic North Korea Risks,” The Korea Herald, January 21, 2010,
[xii] The U.S. Department of Defense’s Quadrennial Defense Review (QDR) identified a wide variety of challenges for the future of the U.S. military—including counter-terrorism, stabilizing fragile states, preventing human suffering due to natural disaster, defeating aggression by adversaries armed with advanced anti-access capabilities, and protecting the global commons—that would be just as beneficial for the ROK military to help perform, not only out of obligation to continue supporting such multinational efforts, but because it could very well be in the national interest of South Korea in the event of further trouble in the DPRK. Robert Gates, Quadrennial Defense Review, February 2010,
[xiii] Donald Kirk, “Time Running Out for Korean FTA,” Asia Times Online, June 4, 2008, http://