
In the midst of recent coverage of North Korea’s provocations, and President Donald Trump and Kim Jong-un’s escalatory rhetoric, South Korean President Moon Jae-in revived the issue of the wartime operational control (OPCON) of the Republic of Korea (ROK) military. During his September 28 address at the ROK Navy’s Second Fleet Command in Pyeongtaek, Gyeonggi Province, Moon stated his administration “is pursuing the early takeover of the wartime operational control.” “The handover on the basis of our independent defense capabilities,” Moon said, will ultimately lead to a remarkable advancement in the fundamentals and abilities of our military.” The issue is significant insofar as it is rooted in the origins and evolution of the U.S.-ROK relationship, yet confusion persists about exactly what it means. Moreover, beyond the operational mechanics of the alliance’s military architecture, it touches upon some of the most enduring and contentious elements in the relationship.

The United States has possessed operational control of the ROK military for nearly South Korea’s entire sovereign existence. The arrangement emerged from the U.S. Army Military Government in Korea (USAMGIK, 1945-48). Soon after the ROK was established on August 15, 1948, General John R. Hodge, head of USAMGIK, and ROK President Rhee Syngman signed an executive agreement whereby South Korea gradually would assume command of its own security forces. However, until the remaining American troops withdrew, the United States would retain operational control over ROK forces. U.S. troops departed in late June of 1949, left behind a 500-man military advisers group, and transferred full control to the ROK.

A year later, during the early stages of the Korean War, U.S. forces returned and prevented South Korea’s destruction by North Korean blitzkrieg. On July 14, 1950, Rhee signed the Taejon Agreement, handing over command authority of all ROK military forces to General Douglas MacArthur, the supreme commander of UN forces, for the remainder of hostilities. Following the 1953 Armistice, and as a condition for the ratification of the U.S.-ROK Mutual Defense Treaty and maintenance of U.S. forces in South Korea, Rhee accepted the November 17, 1954 “Agreed Minute” to the treaty. It stated ROK forces would remain “under the operational control of the United Nations Command while that command has responsibilities for the defense of the Republic of Korea, unless after consultation it is agreed that our mutual and individual interest would best be served by a change.” Change would come in the 1970s.

By the mid-70s, the UN Command’s (UNC) legal status and appropriateness for defending South Korea had become increasingly tenuous. All non-U.S. members of the UNC had removed their combat troops. Also, the UNC itself was criticized by China on the UN Security Council and called into question by dueling resolutions in the UN General Assembly. In November 1978, the U.S.-ROK Combined Forces Command (CFC) was established as a separate entity from the UNC. While the UNC continued to supervise the Armistice Agreement, the CFC and U.S.-ROK alliance became solely responsible for South Korea’s defense.

Creation of the CFC reflected an ongoing process of greater integration between the U.S. and ROK militaries; a process driven by both the U.S. desire to pass more off more of the defense burden to its ally as well as advancements in South Korea’s military strength. More immediately, the CFC was a cooperative means for dealing with President Jimmy Carter’s troop withdrawals. It would enhance ROK operational capability while U.S. units were removed, and also improve the interoperability of alliance forces. Meanwhile, for Seoul, the CFC helped retain the U.S. Forces Korea (USFK) presence and thus a strong U.S. security commitment.

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The CFC marked an important evolution toward more cooperative decision-making in the relationship. Whereas under the UNC the United States essentially held unilateral OPCON over ROK forces, under the CFC OPCON was jointly guided by both allies. Although the commander-in-chief of the CFC (CINCCFC) was a four-star U.S. general, within the CFC he answered to both U.S. and ROK National Command Military Authorities through the annual Security Consultative Meeting (SCM) and Military Committee Meeting (MCM). Additionally, the CFC command structure consisted of an equal number of U.S. and ROK officers, serving under the CINCCFC and his four-star ROK Army deputy commander. Last, CFC OPCON was more restricted than under the UNC, consisting only of ROK and U.S. units on the official List of Combat Units, which the MC could change at any time. Consequently, in times of peace, ROK officers could engage in limited yet independent peacetime operations outside of CFC OPCON.

To be accurate, though, the arrangement was one within which the United States remained first-among-relative-equals. The overwhelming majority of ROK and American forces were placed under both the armistice and potential wartime OPCON of the CFC, headed by the U.S. commander. Thus, as former CINCCFC General B. B. Bell stated, the ROK’s readiness to fight “was ultimately the responsibility of the American commander.” However, in 1994 the ROK assumed armistice or peacetime OPCON of its forces. This meant ROK forces were separate from the CFC during peacetime, and Seoul assumed full responsibility for training, maintaining, and equipping them during armistice conditions. Only with the outbreak of war and the approval of the ROK president would South Korean forces be placed under CFC OPCON. Transfer of wartime OPCOC, therefore, is not automatic. Nonetheless, alliance military operation plans and military exercises, such as Key Resolve, Foal Eagle, and Ulchi Freedom Guardian assume it would quickly occur.

The four-star U.S. general wears two additional hats, as commander of the UNC (CINCUNC) and USFK. As the former, he would receive forces from other UN member states deployed to defend South Korea and be responsible for their OPCON and combat operations. In the latter role, he trains U.S. troops in South Korea, would evacuate all U.S. civilians if instructed to do so by the U.S. ambassador, and would facilitate the complex logistics surrounding the wartime reception of hundreds of thousands of U.S. troops deployed from the United States and other locations.


So, what exactly does this mean? Or, more aptly, what does it not mean? Although the ROK president would transfer the operational control of ROK forces to the CFC, he would not transfer his command over them. The ROK president’s command authority to issue orders covering every aspect of military operations and administration, as well as his chain of command down to the lowest ROK unit commander, would remain inviolate.

Operational control, on the other hand, is derivative of and thus a subset of command authority. It is transferred for a specific period of time and mission, and consists of passing to the CFC the authority to assign tasks to ROK forces already deployed by the ROK president and commanded by ROK officers. However, the U.S. commander cannot change the mission of or deploy ROK forces outside the area of responsibility agreed to by the South Korean president. Nor may he separate ROK units, change their internal organization, divide their supplies, administer discipline, or authorize promotions. As General Bell noted, the U.S. CINCCFC remains under “the firm direction and guidance of both nations’ political and military leaders in a consultative manner.” He receives his strategic guidance from the U.S. Joint Chiefs of Staff (JCS) and secretary of defense and ROK JCS and minister of defense alike.

President Moon and his national security advisors are aware of the above structure and operation of the CFC, how refined it has become, and also how difficult it is to change. So, what is behind their desire to change it? For Moon and ROK progressives, the issue goes beyond the details of the command architecture to what it represents. For them, it symbolizes South Korea’s stark dependence on the United States and exposure to the dictates of external forces. Simply put, for Moon and others, it is an issue of sovereignty. Until they regain full OPCON, they remain semi-sovereign. Although this perspective is strongly criticized by both U.S. officials and conservative South Koreans, it reflects lived historical memory and legitimate concerns about present trends.

As the above history demonstrates, this perspective is rooted in the fact that South Korea’s earliest leaders conceded the authority specifically in order to secure the physical U.S. presence and treaty commitment to defend South Korea, because they could not defend it themselves. Former USFK Commander General Richard Stillwell called it “the most remarkable concession of sovereignty in the entire world.” Furthermore, OPCON later became inextricably bound up with the Gwangju massacre. Consequently, progressive South Koreans, for reasons both real and perceived, saw their democratic aspirations subordinated to the imperatives of an authoritarian dictatorship and U.S. geostrategic stability, with OPCON as the connecting thread. Added to this historical ambivalence toward the United States is the present concern over being entrapped by escalatory actions under President Trump.

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The last point represents a historical irony in that it signals a role reversal. The United States originally structured the command architecture, in part, to constrain the actions of their smaller ally and prevent Seoul from reacting unilaterally or precipitously to Pyongyang’s provocations. Beginning with Rhee Syngman’s disruptive actions during the Korean War and armistice negotiations, as well as his repeated threat to “march north,” U.S. officials were constantly attuned to how South Korea’s actions might precipitate another war, which the U.S. physical presence was specially meant to prevent. The same concern continued with Park Chung-hee, and directly influenced U.S. thinking about what kinds of weapons to sell the ROK as well as the planning around the CFC’s creation and Carter’s troop withdrawal policy.

Dependence is also a source of difficulty in North-South relations. Pyongyang never tires of calling ROK leaders U.S. lackeys. It uses the CFC and U.S. troop presence as justification for dismissing Seoul and instead dealing directly with Washington. If Seoul could take on a more robust, independent role, so the argument goes, Pyongyang would be bound to respect it. As Moon remarked: “When the South has wartime operation control, the North will fear us more.” The question, then, is how does Moon hope to achieve full OPCON transfer? Generally speaking, it could go one of two ways.

The first option involves dissolution of the CFC and creation of two separate, complementary commands. They would communicate and coordinate through an alliance military liaison center, but would retain their own independent command and operational control authority. Former President Roh Moo-hyun (2003-2008) pursued this arrangement during his administration. Moon was one of his closest advisors. The plan was opposed and eventually indefinitely delayed for several salient reasons.

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First, it directly undermined fundamental military doctrine regarding unity of command. This weakens deterrence and complicates the effectiveness of wartime alliance cooperation. In addition, for many South Koreans, particularly conservatives, dissolving the CFC is akin to dissolving the alliance itself. If enacted, they fear the United States would unilaterally withdraw and abandon South Korea once and for all. In the mid-2000s, under Roh, opponents of the plan, including politically influential retired generals associations and conservative lawmakers, framed it in alarmist if not existential terms. In 2006, then GNP lawmaker Hwang Jin-ha remarked that OPCON under the CFC is “symbolic of the alliance. It’s like living in one house under one roof, thinking together about threats and fighting together.” Similarly, in response to Moon’s recent announcement, Hong Jun-pyo, head of the conservative Liberty Korea Party, said, “Return of OPCON is basically disbanding the Korea-US military alliance.” Lastly, from the U.S. perspective, even if there were no real intention to withdraw, greater uncertainty may push Seoul to develop its own nuclear deterrent, spurring further nuclear proliferation, and the failure of the nuclear Non-Proliferation Treaty. These several issues and obstacles are still relevant today.

The second option involves retaining the CFC, but reversing the command hierarchy. Put differently, the CFC stays, yet an ROK general becomes CINCCFC and the four-star U.S general his deputy. Such an arrangement maintains unity of command and a single command and control system, and assuages the existential concerns of conservative South Koreans. Moreover, progressive South Koreans would have achieved their goal. The obvious obstacle to this option is that it would require the U.S. president, Congress, and public accept putting U.S. forces under the OPCON of a foreign commander. Considering the current political climate and Trump’s brand of politics, such a shift would require thorough public explication.

Nevertheless, the second option is possible and likely the favored option for the reasons stated above. Indeed, during last weekend’s MCM and SCM in Seoul, ROK and U.S. defense and military officials reportedly discussed a three-step road map for eventual return of OPCON. Furthermore, the Conditions Based OPCON Transition Plan (COTP) and conversations around the ROK-led Future Alliance Command indicate that it will remain a combined one. As the Joint Communique of the 49th ROK-U.S. SCM states: “The Minister and the Secretary were updated on the draft organization of the future Combined Forced Command [emphasis added] from the MCM and decided to continue to refine the draft through combined exercises and certifications.” The allies agreed to complete the process promptly and submit a detailed plan by next year.


Finally, in either case, South Korea must significantly upgrade its Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) and war-fighting capabilities. In addition to reducing tensions on the Korean Peninsula and in the region, upgrading such ROK capabilities is the main condition necessary for successful OPCON transfer. In his own remarks, Moon acknowledged this when he highlighted the imperative of strengthening the ROK’s Kill Chain preemptive defense system, its Korean Air and Missile Defense (KAMD) system, and developing the Korea Massive Punishment and Retaliation (KMPR) plan. This presents an inconvenient truth for ROK progressives seeking greater independence.

Each of these three military systems remains dependent on U.S. technology, requires new agreements with Washington to extend the range of ROK missiles, and, even in their most upgraded form, presuppose a continued U.S. presence and deeper interoperability with U.S. assets, which the 49th SCM Joint Communique above openly acknowledges. The only way this will fundamentally change is if every last American soldier leaves the Korean Peninsula and the U.S.-ROK Mutual Defense Treaty is abrogated. Yet in all the history above, this has never been on the table, and for Moon and his advisers, likely too imponderable a risk to contemplate.

Clint Work is a Ph.D. candidate in the Jackson School of International Studies at the University of Washington. He writes regularly for The Diplomat‘s Koreas blog.