South Korean President Yoon Suk-yeol’s short-lived martial law order on December 3 stunned the foreign policy establishment in Washington. While condemning Yoon’s subversion of South Korean democracy, many commentators also expressed concerns about losing South Korean support for the hardline posture the United States has adopted against North Korea and China.
With the National Assembly voting to impeach Yoon on December 14, U.S. analysts are worried that the president’s downfall will discredit right-wing politics and open the way for a quick return of a South Korean liberal president, who would be more dovish toward North Korea and China. Commentators warned of weakening military readiness against North Korea and regional alignment to counter China.
Indeed, in Washington, the South Korean liberal coalition is often considered an unreliable partner whose foreign policy orientation goes against U.S. interests. Reacting to the martial law fiasco and its likely precipitation of liberal rule in Seoul, one think tank expert lamented that South Korea’s Democratic Party “favors conciliatory policies toward North Korea and China while distancing South Korea from its alliance with the United States…its policies are not in alignment with U.S. strategic objectives.”
Far from an occasion for hand-wringing, however, the shocking developments in South Korea offer an opportunity for long-overdue self-reflection in Washington on the self-sabotaging nature of U.S. policy toward the Korean Peninsula.
By insisting on military primacy and the goals it produces – preserving asymmetric dominance over North Korea and expanding the South Korea-U.S. alliance’s defensive function from managing North Korean threats to containing China – the United States risks exacerbating security burdens for the alliance and making alliance decoupling with South Korea more likely.
The Rising Costs of Primacy and the Ramifications on the Alliance
Military primacist thinking looms large in the U.S. tendency to perceive South Korea’s liberal coalition as a threat to the alliance. South Korean liberals tend to be more diplomatic toward North Korea, cautious about choosing between the United States and China, and pessimistic about military alignment with Japan. These inclinations are antithetical to the interest in maximizing U.S. military influence among Washington primacists. Based on this dynamic, it has been natural for the Washington establishment to feel that ties loosened under South Korean liberal leadership, and to blame Seoul’s incompatible foreign policy for damaging the alliance’s “ironclad” cohesion.
In reality, Washington’s pursuit of regional military dominance has been a steady source of instability for the South Korea-U.S. alliance. It has increased security burdens, sharpened domestic divisions in South Korea, and ultimately weakened alliance resilience.
Military primacist thinking has played a guiding role in Washington’s reflexive preference for heavy U.S. forward deployments and high-tempo saber-rattling to deter North Korea over the years. Large-scale, fast-tempo joint exercises and asset deployments can bring about negative consequences for deterrence, including creating pretexts for North Korean provocations and destabilizing crisis dynamics. Nevertheless, such downsides are often discounted for the sake of military readiness and strategic dominance.
Concerns with primacy have also driven strategists and policymakers to foreclose any scenario of peacebuilding with North Korea if it hinges on reducing U.S. military influence on the peninsula. One notable example is the enduring U.S. resistance to formally ending the Korean War.
When the previous liberal South Korean President Moon Jae-in called for a declaration ending the Korean War in his effort to promote negotiations with North Korea, it drew widespread negative reactions across Washington. There was arguably no practical reason to oppose the initiative; an end-of-war declaration, by itself, is symbolic and would have no direct impact on the concrete instruments of containment on North Korea. If anything, it could help assuage the adversarial political dynamics that undermine the trust-building necessary for nuclear negotiations.
For skeptics, the overriding concern tends to be about the potential discussion of U.S. military withdrawal in further negotiations down the road. One major pundit frankly reacted to Moon’s peace initiative, saying no attempts at negotiations with North Korea should risk degrading U.S. forces in Korea.
Pyongyang, which perceives the heavy presence of U.S. forces on the peninsula as a threat, would of course like to see a reduced U.S. military presence. But there is no conclusive evidence that Pyongyang sees full-scale U.S. withdrawal as an absolute non-negotiable requirement for its security. And deterring North Korea might not require a large number of U.S. boots on the ground. A drawdown in U.S. troop numbers could be compensated by smaller yet modernized U.S. forces and enhanced South Korean defense investments. These conditions may leave room for the United States to not rule out military withdrawal in its entirety from the table.
To be sure, there are a range of negative consequences that could arise from a failed peace deal – including the reputational cost of diplomatic failure, giving North Korean leader Kim Jong Un more legitimacy on the international stage, and North Korea’s exploitation of economic concessions. Whether these risks outweigh the danger of playing an endless game of chicken with an increasingly nuclear-capable adversary should be at least debatable. Yet, in primacist thinking, which prioritizes sustaining military influence above all else, what might otherwise be seen as a tolerable level of risk in formally ending the Korean War and pursuing a peace deal becomes unbearable and must be avoided.
Washington’s preoccupation with primacy has narrowed the prospects for security negotiations with North Korea. And the repercussion – North Korea’s pursuit of more powerful and credible nuclear deterrents to overcome the military imbalance on the peninsula – appears to increasingly challenge alliance cohesion as time goes by, casting greater doubt on the U.S. defense commitment to South Korea and raising South Korean fears of abandonment.
Even more worryingly, Washington’s commitment to a zero-sum security competition with China and its subsequent increasing temptation to extend the South Korea-U.S. alliance’s defense perimeter from North Korea to China will compound the challenge to alliance cohesion. After all, Washington’s attempts to transform South Korea into a regional “pivot” against China over the years have appeared to weaken the alliance.
One example is the Obama administration’s deployment of the THAAD (Terminal High Altitude Area Defense) anti-missile system on South Korean soil. Countering China loomed large in the background, despite THAAD being painted as predominantly for deterring North Korea. Beijing’s subsequent economic retaliation and hardline turn against Seoul damaged China-South Korea security relations. Yet rather than advancing the U.S. aim of organizing its allies against China, the controversy heightened wariness in South Korea of getting caught in the China-U.S. crossfire, enhancing cautious South Korean sentiments about alliance security and regional strategic cooperation with the United States. If South Korea was more confident in its individual security relationship with China, it might worry less about how its actions would anger Beijing.
The Biden administration’s attempt to build a Japan-South Korea-U.S. trilateral military alliance against China has also backfired. Despite the large base of South Korean moderate and liberal forces opposed to unconditional military alignment with Japan at the compromise of wartime historical disputes, Washington willfully ignored domestic divisions in South Korea and blindly encouraged the Yoon administration’s undemocratic pursuit of the process.
Embittered by Yoon’s unilateralism and now poised to enjoy strong popular support against the backdrop of the martial law fiasco, an incoming liberal administration in Seoul will have both eagerness and justification to erase Yoon’s corrupt legacy – in which trilateralism with Japan was central. The Washington establishment may blame South Korea’s liberals for causing disruptions and instability in the alliance, but U.S. policymakers would be better served by reflecting on their own mistake of adamantly pushing for an alliance policy that appeals only to the thinning right-wing side of the polarized South Korean politics.
Public polls consistently reflect divisions and mixed feelings among South Koreans about how their country should approach China. Many South Koreans are wary of an assertive great power’s existence on their doorstep and agree on the necessity reducing that security risk. The sense of risk aversion translates into support for the military alliance with the United States and efforts to reduce economic overreliance on China, but also opposition to both “decoupling” with the Chinese market – a significant source of South Korean trade income and supply chains – and an adversarial military relationship with China.
A 2023 survey by a South Korea-based think tank showed that 80 percent of South Koreans view bilateral ties with China as important, and half would prefer a neutral position in a severe China-U.S. conflict. Another survey by the same institution from 2022 revealed that an underwhelming 7 percent of South Koreans supported economic decoupling with China, and just 20 percent would support South Korean direct involvement in U.S. military operations to defend Taiwan against China.
Remarks by Lee Jae-myung, the South Korean liberal party chief who could be the next president, questioning why South Korea should meddle with the Taiwan issue might raise the eyebrows of pundits in Washington, but his approach resonates with many South Koreans and reflects their serious concerns.
Although South Koreans might turn more overtly anti-China if Beijing is seen to pose increasingly serious and direct threats in the future, the South Korean inclination toward a risk-averse, pragmatic foreign policy – reflecting the country’s geographical reality and economic structure – seems unlikely to go away for the time being. Yet calls and expectations for South Korea to assume a major role in U.S. war planning against China over Taiwan are growing in Washington. Some strategists, including an influential former high-level Trump administration defense official who might return to government, even argue that South Korea should bear sole responsibility for deterring North Korea while allowing U.S. forces in Korea to focus on a Taiwan contingency.
This seemingly growing U.S. view of South Korea as a frontline military operational base against China could create widespread fear of entrapment among South Koreans, intensify their already strong sense of insecurity from North Korean nuclear threats, and risk driving South Korea further away from the alliance.
When the security burdens of the alliance are perceived to exceed those of autonomy, more South Koreans may begin to question the value of maintaining the alliance. By inflating the threats posed by China as existential – an assessment many outside the United States disagree with – and pressuring South Korea to share the immense security burden of fighting a new Cold War against China, all the while failing to mitigate North Korean nuclear threats, Washington might precipitate alliance decoupling.
The Path Forward for the Alliance
Washington’s continued strategic orientation on primacy can prove to be a recipe for maximizing South Korea-U.S. security burdens and undercutting the alliance’s sustainability. To foster a resilient, long-term alliance with South Korea, the United States needs to abandon primacy as a goal to achieve through the alliance.
Washington should not let the motivation to preserve and expand the existing U.S. forward military presence get in the way of pursuing less confrontational, more defensive deterrence that could more effectively stabilize the threat environment on the peninsula.
The current South Korea-U.S. deterrence posture, relying heavily on muscular demonstrations of the alliance’s military superiority and offensive capabilities to contain North Korea, creates undesirably large room for misperceptions and overreactions that make North Korean nuclear use more likely. A more restrained posture oriented around defensive capabilities and signaling can improve deterrence by moderating threat perceptions, promoting crisis stability, and lowering the risk of inadvertent escalation.
Incoming U.S. President Donald Trump has expressed an interest in renewing dialogue with North Korea. A South Korea-U.S. deterrence posture that more clearly reflects defensive intent and gestures of de-escalation could help create the necessary diplomatic momentum. It should also be kept in mind that there are possible ways to maintain wartime superiority against North Korea without a large-scale U.S. ground presence in South Korea. Accepting this possibility could expand the scenario of security negotiations with North Korea.
Next year, with the anticipated arrival of a South Korean liberal government, which would place greater priority on tension reduction and diplomacy with North Korea, Washington will have a timely opportunity to make bold policy changes.
If the incoming Trump administration insists on pressing the kind of zero-sum economic and military conflict with Beijing that Seoul would find unacceptable, it will be risking alliance distancing and decoupling. Instead, Washington should explore more acceptable and mutually beneficial roles South Korea could play in China-U.S. relations, such as facilitating regional cooperation on Korean Peninsula crisis management and nuclear diplomacy.
Countries in Asia are wary of China and would not want to see its unilateral regional hegemony. However, Washington should not misinterpret this skepticism toward Beijing as calls for containment or exclusion of China. What many Asian countries aspire to is an inclusive regional order in which the United States and China maintain a stable balance of power without engaging in a zero-sum confrontation that jeopardizes security and economic interests that are deeply connected to both great powers.
U.S. regional alliances, including with South Korea, can play a pivotal role in promoting an inclusive regional order and maintaining positive U.S. influence across Asia. However, if the alliances remain centered on the pursuit of military primacy, Washington would find itself destabilizing the region and widening strategic divergences with regional allies and partners at its own peril.