A Hawkish Dove? President Moon Jae-in and South Korea’s Military Buildup

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Has South Korea’s President Moon Jae-in, a strong proponent of a peaceful engagement policy toward North Korea, turned into a hawk? On Sept. 7, South Korea successfully tested a submarine-launched ballistic missile, becoming only the eighth country (and the first one without nuclear weapons) to possess that type of capability. It was the latest step in South Korea’s ongoing military buildup.

Since Moon, a member of South Korea’s Democratic Party, took office in 2017, the country’s defense budget has increased by an average of 7.4 percent annually. Under the two previous conservative administrations of Lee Myung-bak and Park Geun-hye, the defense budget only rose by between 4 and 6 percent annually. By 2022, South Korea is expected to spend more on defense than Japan — whose gross domestic product is three times as large — and become the fifth- or sixth-biggest spender on defense in the world. In addition, despite Pyongyang’s vehement protests, South Korea has resumed joint military exercises with the United States.



Moon’s military buildup stands in stark contrast to his dovish policy toward North Korea. Having served as a close aide to President Roh Moo-hyun from 2003 until 2008, during the peak of the “sunshine era,” Moon restored the engagement policy toward North Korea shortly after taking office. He has spent significant political capital on this effort, which culminated in three inter-Korean summits in 2018 and a military agreement during the same year. Through this process, the two Koreas agreed to de-escalate military tensions, end hostile acts, and build a sustainable peace on the Korean Peninsula. While the military pact is not an arms control treaty, South Korea’s recent military buildup, which includes advancing missile capabilities targeting North Korea’s strategic assets and aimed at “decapitating” the North Korean leadership, arguably violates the spirit of the inter-Korean agreements. North Korean state media has criticized Seoul’s arms development as an “unpardonable act of perfidy” that threatens to undermine peace and stability.

What explains Moon’s seemingly contradictory approaches to national security? The answer lies in his goal for South Korea to take back wartime operational control (OPCON) from the United States. To achieve that ambition, South Korea needs to reduce its military dependence on the United States and enhance its own capabilities to counter North Korea’s nuclear and missile threats. Seen in this light, the Moon administration’s military buildup starts to make sense. 

The History of Wartime Operational Control

For the past seven decades, South Korea has lacked full control over its military. Shortly after North Korea’s invasion in June 1950, South Korea transferred OPCON to the United Nations Command, which was led by U.S. Gen. Douglas MacArthur at the time. After the war, the United States and South Korea codified the transfer, not only as a means to defend South Korea but also as a way for the United States to rein in potential South Korean aggression against its northern neighbor. When the U.S.-South Korean Combined Forces Command was established in 1978, OPCON was transferred from a U.N. commander to an American commander.

After the end of the Cold War, in 1994 the United States transferred peacetime OPCON back to South Korea. But, if a war erupts, an American commander of Combined Forces Command would assume OPCON and lead the fight, while a South Korean general would serve as deputy commander. In 2007, President Roh Moo-hyun, a liberal, pushed for the transfer of wartime OPCON, which President George Bush agreed to complete by April 2012. If wartime OPCON was transferred to South Korea, Combined Forces Command would subsequently be led by a South Korean commander, who would have the authority to make certain strategic decisions on the battlefield.

Roh’s conservative successors postponed the plan due to their concerns about the impact that OPCON transfer might have on the U.S. security guarantee, as well as North Korea’s increasing nuclear threats. In the wake of North Korea’s second nuclear test in 2009, President Lee Myung-bak pushed back the planned transfer date until 2015. In 2014, Presidents Park Geun-hye and Barack Obama agreed to delay the transfer indefinitely until “critical ROK and Alliance military capabilities are secured and the security environment on the Korean Peninsula and in the region is conducive to a stable OPCON transition.” The U.S. and South Korean governments established a conditions-based transition plan under which the two sides regularly review the security situation: They have not yet concluded that South Korea has met the necessary conditions.

Within South Korea, conservatives and liberals have fiercely debated the issue of wartime OPCON. While transferring it would not trigger the withdrawal of U.S. troops from South Korea nor the termination of the American security guarantee, South Korean conservatives view America’s continuing hold on wartime OPCON as useful insurance against U.S. abandonment. By contrast, South Korean liberals view OPCON transfer as necessary to achieving full national sovereignty and control over the country’s self-defense, even though the South Korean president can essentially veto American OPCON of Combined Forces Command, anyway. That is because the U.S. commander can only assume wartime OPCON with the approval of both the American and South Korean presidents. Further, OPCON transfer would not restore South Korea’s “full sovereignty” in the liberal politicians’ sense of the term. Even after OPCON transfer, the commander of the alliance’s warfighting command would remain subject to the authority of both Washington and Seoul. The misperceptions and misunderstandings about what the transfer of wartime OPCON implies — among both South Korean conservatives and liberals — have turned this military issue into a political controversy.

Moon’s Military Buildup

On the campaign trail in April 2017, Moon made it clear that his government would “take back wartime OPCON early” to deter North Korea’s nuclear and missile threats and would “take charge of our defense by ourselves.” Aiming to complete the transfer before his tenure ends in May 2022, Moon has initiated a military buildup. The rationale is clearly stated in South Korea’s 2018 Defense White Paper: South Korea’s increased defense spending is aimed to “deter and respond to nuclear and missile threats as the top priority and build key military capabilities for wartime operational control (OPCON) transition to establish the ROK Armed Forces-led combined defense system.”

To meet the conditions required for OPCON transfer, South Korea needs to enhance its ability to lead the combined command and counter North Korea’s threats. South Korea has to have the intelligence, surveillance, and reconnaissance capabilities to locate and monitor North Korea’s nuclear and missile programs in order to detect any impending North Korean attack against the South. This is currently one of the most critical gaps in South Korea’s military capabilities, and an area in which the country still relies heavily on the United States. Under the conditions-based plan for OPCON transfer, South Korea is also required to have high-explosive shells and ballistic missiles that would allow it to launch preemptive attacks against North Korea’s nuclear and missile facilities. Additionally, South Korea would need to have effective missile defense systems in case deterrence fails.

To meet these conditions, Seoul is enhancing its military capabilities. South Korea has recently acquired new surveillance assets, including Global Hawk unmanned aircraft with sophisticated imaging and electronic signals sensors that will improve the country’s situational awareness and intelligence-gathering capabilities. Seoul is also developing homegrown hypersonic and precision-guided missiles, high-yield warheads, and satellite navigation systems. Additionally, South Korea is investing about $2.5 billion in the research and development of an advanced missile defense system modelled after Israel’s Iron Dome, with the goal of deploying it by 2035. Moon’s administration is also pursuing nuclear-powered submarines to counter North Korea’s submarines and that could give Seoul the ability to develop nuclear weapons in short order. Lastly, the Moon administration resumed joint U.S.-South Korean military exercises in 2019 with the goal of verifying the South Korean military’s readiness to take back OPCON (although this plan has been frustrated as the exercises were scaled back due to COVID-19).

The Moon administration is trying to keep its military buildup as low key as possible, which speaks to its real intention. U.S. Ambassador to South Korea Harry Harris’ April 2020 tweet about South Korea’s procurement of sensitive military assets, such as Global Hawks and F-35A next-generation fighter jets, generated a controversy because Seoul had been reluctant to make the procurement public. As a South Korean military source cited by Yonhap said, “Our basic stance is that we do not publicize such things for security reasons.” Even though the assets South Korea is acquiring and developing are geared toward defending the country from North Korea’s nuclear and missile threats, if the primary goal was deterrence, demonstrating rather than hiding these new capabilities would be the more logical strategy. After all, deterrence works only when the enemy knows that you have the will and the capability to inflict unacceptable harm on them. The Moon administration’s desire to downplay new capabilities suggests that the aim of Seoul’s military buildup is not primarily deterrence, but satisfying Moon’s ambition to meet the conditions for OPCON transfer.

Some argue that President Trump’s alliance policy, which caused a fear of abandonment among U.S. allies, explains Moon’s military buildup. However, in reality, a buildup aimed at facilitating transfer of wartime OPCON both predated and outlasted the Trump presidency. In pursuit of that goal, President Roh Moo-hyun enhanced military capabilities and increased the defense budget by over 8 percent annually during his tenure from 2003 to 2008. In addition, Moon’s military buildup has not slowed down despite President Joe Biden’s efforts to repair U.S.-South Korean relations.

The Future of the Military Buildup

South Korea’s military buildup will likely continue after Moon’s tenure ends in May 2022. With the conservative People Power Party still in turmoil four years after the impeachment of Park Geun-hye, the Democratic Party’s most promising candidate, Lee Jae-myung, is leading in the polls for the March 2022 presidential election. Like Moon, Lee has been a strong proponent of the transfer of wartime OPCON, as well as national self-defense and sovereignty more generally. Recently, he said that despite Pyongyang’s protests, U.S.-South Korean joint military exercises are related to OPCON transfer and should therefore be resumed.

With merely eight months remaining in Moon’s term of office, not only has engagement with North Korea floundered, but the transfer of OPCON looks increasingly unlikely to happen before the end of his administration. Both objectives were admittedly difficult. However, Moon’s simultaneous pursuit of two contradictory goals — wartime OPCON transfer and peaceful engagement with the North — may have hindered the chance of achieving either. Moon’s military buildup, one condition for OPCON transfer, hampers the creation of a peaceful environment on the Korean Peninsula, another condition for such transfer. If his top priority was taking back wartime OPCON, Moon should have built up South Korea’s military capabilities to meet the necessary conditions before pursuing peaceful engagement with North Korea. Alternatively, if engaging North Korea was the top priority, Moon should have delayed a military buildup. When states set incompatible goals, it is imperative that they also have policy priorities. Otherwise, they run the risk of achieving nothing at all.



Lami Kim is an assistant professor in the department of national security and strategy at the U.S. Army War College and a 2020–2021 U.S.-Korea NextGen Scholar under the sponsorship of the Korea Foundation. The views expressed are those of the author and do not necessarily reflect the official policy or position of the Department of Defense or the U.S. government. 

Image: U.S. Air Force (Photo by Staff Sgt. Alex Fox Echols III)