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Security and Defense Issues Facing South Korea’s Next President

From responding to North Korea to long-term approaches toward China, the U.S., and Japan, South Korea’s next president will have a full agenda from day one.

Security and Defense Issues Facing South Korea’s Next President
Credit: Republic of Korea Armed Forces

The presidential election currently underway in South Korea is remarkable for its focus on domestic spending, even on a kind of economic populism. Security and defense issues, which have dominated previous elections, are hardly being mentioned, despite heavy pressure from the United States for South Korea’s closer involvement in its Indo-Pacific Strategy.

There are, nevertheless, several intractable problems bearing on security which President Moon Jae-in leaves behind for his successor, whoever that will be: a growing debt burden, a still-raging pandemic, increasing threats from North Korean WMD, and China’s continuing harassment of the South Korea-U.S. alliance.

Will the South Korea-U.S. Alliance Be Affected by the Outcome of the Presidential Election?

The next administration will inherit a South Korea-U.S. alliance somewhat shaken by recent developments. Moon’s successor will have to decide how best to enhance Seoul’s capability to deter North Korean threats in order to maintain the strength and credibility of the U.S. alliance.

Following the 9/19 comprehensive military agreement between the two Koreas, which removed both side’s guard posts in the DMZ, and also the attempt to transfer wartime operational authority (OPCON) to the South Korean military, the current combined defense posture against North Korea has been significantly weakened.

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Facing conventional, nuclear, and missile threats from North Korea, supported by China and potentially by Russia, the South Korea-U.S. alliance needs to integrate its command-and-control systems into a single unified structure.

The ROK and U.S. militaries also need to establish deep and resilient interoperability, a common operational picture for the two commanders, and a joint/combined defense posture that incorporates doctrines and operational concepts within the overarching U.S.-led Indo-Pacific Strategy.

South Korea must enhance its complementarity, sharing the U.S. burden by developing more active and preemptive roles, but Seoul also has to balance South Korea’s interests between the two great powers’ spheres of influence. This balance can be very challenging, as shown by the deployment of the Terminal High Altitude Area Defense system in 2017 to cover the U.S. forces stationed at Camp Humphries, which provoked economic retaliation from China.

The next South Korean president will also have to firm up Moon’s promises of closer involvement with the U.S. Indo-Pacific Strategy, intended to constrain China’s military expansionism. The roles and missions of the South Korea-U.S. alliance will have to be extended, and perhaps South Korea will join U.S.-led multilateral mechanisms, such as Quad Plus or AUKUS Plus.

The next president, whether liberal or conservative, will oversee the expansion of South Korea’s roles and missions in several ways: resuming field-based combined drills, agreeing on the details of Strategic Guidance Planning, rewriting Operational Plan 5015, and enhancing integrated deterrence in all domains.

How Should the Next Administration Respond to Chinese Military Expansionism?

Moon has tried to exercise some strategic autonomy amid China-U.S. tensions, choosing one of the great powers according to the situation. But this so-called security/economy separation has proved difficult to implement.

From the Korean perspective, the most important quarrel between China and the United States concerns the South China Sea. The OPCON issue is relevant here, because the ROK military holds this authority in peacetime, which is transferred to the U.S. military in wartime. But the current situation in the South China Sea can be regarded as a peacetime operation, and there is thus no specific reason for the South Korea-U.S. alliance to become caught up in the disputes in the South or East China seas, or in the Taiwan situation.

Seoul’s position on the South China Sea has been low-profile, and there is no reason to change this stance, as South Korea is not directly involved. The South Korea-U.S. alliance has always focused on North Korean military provocations, and there are non-military ways for South Korea to support the U.S. and ASEAN in the South China Sea, for example, by endorsing the U.N. Convention on the Law of the Sea, working toward a binding ASEAN-China Code of Conduct, and cooperating in other international initiatives concerned with the maritime environment, including adaptations to climate changes.

The recent Malabar 2021 naval exercises, involving Australia, Japan, India, and the United States, were explicitly designed as a rehearsal for containing China. In that context, for South Korea to join the Quad would be unnecessarily provocative. However, Seoul participates in other multilateral security dialogues, such as the East Asia Summit and the Asia-Europe Meeting, and the Moon administration has already agreed to support some Quad subcommittees dealing with non-military issues. This kind of semi-detached observer status is unlikely to disturb China.

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China’s military might is deployed in the South China Sea, East China Sea, and near Taiwan, with little prospect that the seas around the Korean Peninsula will soon be targeted. Japan has taken a somewhat surprising interest in Taiwan’s security, claiming that Japan’s own security is compromised by the geographic disposition of Chinese military forces in the region, but South Korea has no such concerns.

South Korea is facing steadily increasing conventional, nuclear, and missile security threats from North Korea, and needs to focus its foreign policy and military policy on the Korean Peninsula. For Seoul to become too closely identified with U.S.-led anti-China policies would be a serious strategic error.

Managing Japan-South Korea Relations

The United States clearly wishes for its trilateral security cooperation with Japan and South Korea to be strengthened, but is reluctant to become involved in discussing or commenting on the issues that divide its two most important East Asian allies. The U.S. takes no position on the historical injustices perpetrated by Japan, such as forced labor and sexual slavery, which still cast a long shadow today. Having suffered as victims, Koreans feel let down by the U.S. failure to acknowledge the asymmetry of the situation. Even on such less emotionally fraught issues as the status of the Liancourt Rocks – administered by South Korea as Dokdo but claimed by Japan as Takeshima – or the naming of the sea between the two countries, the United States is silent.

Domestic sentiment in South Korea will limit the ability of the next administration to repair relations with Japan, even if the next president is disposed to attempt it. The U.S. Indo-Pacific Strategy needs Japan and South Korea to mend fences, but the United States still refuses to get involved. Moreover, there are other difficulties hindering closer trilateral security cooperation, such as the poor level of interoperability between the ROK military and the Japanese Self-Defense Forces.

Military tensions between two Koreas have been managed for seven decades by the South Korea-U.S. alliance. Historically, the United States has dominated the alliance, but Seoul is now becoming a more capable and complementary partner. Given the extreme domestic sensitivity that any South Korean administration would face in moving closer to Japan, together with the fact that the targets of the trilateral alliance, North Korea and China, have their own historical grievances against Japan, the United States cannot reasonably expect South Korea to become Japan’s bosom buddy anytime soon.

China and North Korea are a real threat to Japan, just as they are to Seoul. A military crisis involving China might begin on the Korean Peninsula, but it would quickly escalate beyond it, with preemptive attacks on major U.S. bases across the region, and on Japanese bases also. Any security situations short of such a dire conflict will continue to be managed through existing mechanisms, such as the General Security of Military Information Agreement. At present there is no prospect of closer military relations between Japan and South Korea.

Can South Korea Sustain Its Middle Power Status?

Some theoretical analyses discuss the concept of middle powers, which in East Asia would include South Korea, Japan, India, Australia, and some of the members of the Association of Southeast Asian Nations. The United States or China in practice both compete for the support of these middle powers. South Korea is well established as a responsible and effective middle power, with substantial diplomatic, military and economic clout.

Like any other nation, South Korea tries to pursue its national interests, for which a credible defense posture against North Korea is fundamental. The concept of middle-power status is sometimes understood as a way to avoid involvement in China-U.S. rivalry, but the South Korean stance is more accurately characterized as strategic autonomy. Seoul has been more successful than the other regional middle powers in carefully balancing between the United States and China, shifting its position as events require, in order to maintain its national interests.

The most recent challenge to the balance is the U.S. Indo-Pacific Strategy, which is widely perceived as directed against China. Moon has committed South Korea to some involvement in this policy, as yet vaguely defined, and in the long term it is still plausible for Seoul to survive as a reasonably autonomous middle power.

What Should the Next Administration Consider in Formulating Its National Security and Defense Strategies?

The next South Korean administration will face some formidable challenges. The U.S. decline as a world power is particularly obvious in East Asia, where it may become difficult to maintain the kind of liberal and democratic good order now enjoyed by South Koreans. China continues to build up its economic and military power, and clearly intends to reestablish the regional dominance it lost in the 19th century, with something like a Chinese version of the Monroe Doctrine. If the U.S. weakens, or loses interest, then China will make the South and East China Seas into Chinese possessions, and the seas around the Korean Peninsula will be next. China also maintains North Korea as a buffer against South Korean and U.S. influence, and since the North Korean economy is dependent on China, the Kim regime is a tool that China can use to threaten or distract South Korea, the U.S., and also Japan.

Moon’s summit with U.S. President Joe Biden last May laid out some strategic policies, which the next South Korea administration will likely adopt without alteration. His policy toward North Korea is more contentious, however; he has consistently attempted to promote peace, for example through the 9/19 agreement to reduce military tensions, and also with the suspension of South Korea-U.S. combined drills since 2018. The recent North Korean missile launches are seen by many as demonstrating the failure of Moon’s security policies, and the next president will doubtless make some changes.

The incoming administration may try to repair Japan-South Korea relations, as the United States desires, but this may only be lip service. A part of the population wants policies to put South Korean interests first, by responding to events through balanced and flexible diplomacy, and reducing the threat from North Korea without engaging in serious conflict. This would be easier if the new president improves relations with China.

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By contrast, many South Koreans want to draw a line under the Moon era by reinforcing the South Korea-U.S. alliance. This may entail an expansion to areas beyond the Korean Peninsula, most likely the South Pacific region, but the next administration will surely not join Quad or AUKUS, though it may get involved with associated non-military projects, such as supply chain resilience, AI adoption, supplementary semiconductor provision, space and cyber-domain security, and public health improvements.

In conclusion, South Korea’s strategic autonomy is inevitably affected by the rivalry between the United States and China. The next administration’s foreign policy and military strategy will certainly involve reshaping the South Korea-U.S. alliance, but whatever the presidential candidates say during the campaign, any new president will have to respond flexibly to a constantly changing security environment.