Navigating South Korea's plan for preemption

South Korea has invested in systems designed to preempt North Korean nuclear launch and attack missiles before they are launched and the leadership and command and control nodes that support Pyongyang’s weapons of mass destruction enterprise. This system is a network of interlinked offensive and defensive missiles and multidomain platforms and ultimately is undergirded by the assurance that South Korean President Yoon Suk Yeol has sought since winning election: A more robust nuclear guarantee from the United States.

The Biden administration has sought to manage South Korea’s interest in both nuclear weapons and preemption since taking office. And, in April, the two sides reached agreement on the first-ever standalone alliance document issued at the presidential level solely devoted to the U.S. extended deterrence commitment to South Korea, according to War on the Rocks.

The Washington Declaration’s takeaway was the establishment of an alliance Nuclear Consultative Group, signaling a potentially unprecedented level of bilateral consultation surrounding U.S. nuclear policy and planning. However, the declaration’s mention of the Republic of Korea’s yet-to-be established Strategic Command, dubbed ROK STRATCOM for short, has received minimal attention. The Biden administration’s effort to link this command with Republic of Korea/United States Combined Forces Command suggests that Washington is willing to offer more concrete assurances to Seoul but also wants to try and limit escalation in the event of a crisis.

South Korea’s Strategic Command aims to enhance the country’s nonnuclear strategic deterrence in different ways. First, it seeks to bolster deterrence by denial — to deter North Korea’s nuclear and unconventional threats by making them infeasible or unlikely to succeed. The goal is to undermine North Korean confidence that it can achieve its objectives through nuclear coercion. Second, Strategic Command would enhance deterrence by punishment by threatening to impose substantial costs up to and including decapitation strikes against North Korean leadership in the event of North Korean nuclear or weapons of mass destruction use against South Korea.

Even for the most focused Korea watchers, it was noteworthy that Korea’s Strategic Command was included in the declaration. So, what is this seemingly obscure command, and why was it included in a presidential-level alliance document?  This command’s sudden prominence reflects several interconnected yet conflicting currents within the U.S.-Korean alliance. These include Seoul’s efforts to leverage advanced conventional means to achieve nonnuclear strategic deterrence; an alliance effort to build conventional-nuclear integration; and a sometimes contentious dance between U.S.-imposed constraints and South Korean hedging, grounded in the alliance’s history yet more urgent in the face of a rapidly advancing North Korean threat and shifting strategic environment.

Strategic Command and Nonnuclear Strategic Deterrence

One reason for limited coverage of Korea’s Strategic Command is that it does not exist. It is supposed to be established in 2024. It was first mentioned during South Korea’s 2022 presidential campaign as part of President Yoon’s defence and security platform. Since then, the Republic of Korea’s Strategic Command — as both concept and command structure — has mostly been covered in defence-related outlets and occasional South Korean media reports. Most prominently, the Yoon administration included several paragraphs on the command in the country’s 2022 Defence White Paper. Its first-ever mention in a bilateral alliance document was in the April 12 Joint Press Statement for the 22nd Korea-U.S. Integrated Defense Dialogue. The Washington Declaration was the second.

Once this command is established, it will control South Korea’s 3K Defense System. The 3K Defense System consists of three platforms and concepts, each beginning with the letter “K”: Kill Chain platform, Korea Air and Missile Defense system, and Korea Massive Punishment and Retaliation plan. Under Strategic Command, the 3Ks would call upon a similar array of capabilities from across the South Korean military. These include the Army’s Strategic Missile Command’s Hyunmoo family of ballistic and cruise missiles, which would play a role in both the Kill Chain and Massive Punishment and Retaliation plans. In addition, the Air Force Air Defense Missile Command’s PAC-3s, F-35As, Global Hawk surveillance aircraft, and Cheongung II M-surface-to-air missiles would be included in each component of the 3K system. So, too, would the Navy’s 3,000-ton submarines with sub-launched ballistic missiles and KDX-III Aegis destroyer-based SM-2 missiles, as well as South Korea’s future military surveillance satellites, cyberwarfare and space-focused forces, and special forces units.

These weapons — and supporting infrastructure —are designed for preemptive and retaliatory strikes, along with air and missile defence systems to defend against preemptive or retaliatory North Korean missile strikes. Strategic Command will not be a force provider. Rather, it will fall under South Korea’s Joint Chiefs of Staff and will command and control all South Korea’s strategic weapons, implement the 3K Defense System, and set related military policy and plans. At present, it is unclear how or to what extent Strategic Command would come under the Republic of Korea/United States Combined Forces Command. This is the controlling element of the joint forces on the peninsula and is headed by a U.S. general, with a South Korean officer serving as the deputy.

There are voices in South Korea’s political and military establishment who want to keep Strategic Command independent of the United States. An independent air and missile command would, in theory, allow for South Korea to act quickly — and independently — of the United States. This would be advantageous if South Korean officials were concerned that the United State might try and prevent South Korea from preempting attack, over concerns that any such attack could escalate to North Korean nuclear strikes on the U.S. homeland.

Currently, all 3K Defense System assets are individually managed by the South Korean Army, Air Force, and Navy. South Korea’s Strategic Command would, in theory, greatly enhance jointness and the more efficient command and operation of those assets by combining those divided strategic assets under one single unit. The organization will be commanded by a three-star general or admiral, with the various military services rotating the leadership among them.   Strategic Command is intended to bolster deterrence by enhancing jointness and increasing the military’s operational efficiency. The idea would be to create a seamless system and project that seamlessness toward North Korea to limit its ability to exploit gaps in South Korea’s defense.

This concept did not come out of nowhere. It has grown directly out of Seoul’s concerted effort to build up its advanced conventional capabilities and a nonnuclear strategic deterrent and defence system to counter a rapidly evolving North Korean nuclear, missile, and weapons of mass destruction threat. The 3K Defense System originated in early 2013 at the tail end of President Lee Myung Bak’s rule and was dubbed the three axis system. It was further developed under Lee’s conservative successor President Park Geun Hye. In 2019, the progressive administration of President Moon Jae In changed the name to the “system to respond to nuclear and other weapons of mass destruction,” the Kill Chain to the Strategic Target Strike, and the Korea Massive Punishment and Retaliation plan to Overwhelming Response. 

The name change was mostly cosmetic. However, it aligned with Moon’s policy of inter-Korean reconciliation and engagement and his liberal government’s policy of engagement with North Korea to reduce tensions. The new names were meant to reduce the sense of hostility of the previous ones. Regardless, the basic makeup of the system remained the same, and the Moon administration — more so than its conservative predecessors — took steps to upgrade the system’s advanced capabilities.

The first K — the Kill Chain — is a preemptive strike system against Pyongyang’s nuclear and missile facilities. On paper, the Kill Chain concept consists of a range of capabilities, including deep strike missiles and radar-evading fighters. It is to be activated in the event Seoul is faced with a credible threat of an imminent North Korean nuclear launch. The system is geared toward finding, fixing, targeting, and engaging various North Korean targets before they can be launched.

The second K — Korea Air and Missile Defence system — is meant to provide multi-tiered, layered defence of critical facilities and population centres by intercepting air, missile, and artillery threats. The air and missile defence system will eventually consist of long- and medium-range surface-to-air missile defence systems; low-altitude missile defence systems; and U.S. missile defence systems forward deployed in South Korea.

The third K — Korea Massive Punishment and Retaliation plan — assumes that a North Korean nuclear or unconventional attack has already occurred. If this were to occur, South Korea would retaliate with short- and longer-range precision missiles, advanced strike aircraft, and potentially the infiltration of special operations forces. The targets would be a combination of countervalue, counterforce, and leadership decapitation strikes.

Under Strategic Command, each of the 3Ks will be linked in thinking and for warfighting purposes. Depending on the course of events, pace of escalation, and North Korean actions, each component of the system could operate simultaneously. Although each component of the 3K paradigm has a distinct purpose, they would be utilized in a synchronized fashion under Strategic Command to deter and, if need be, defend and counterattack against North Korea’s nuclear, missile, and unconventional threats.

Conventional-Nuclear Integration Alongside Constraints and Hedging

South Korea does not currently possess all the necessary capabilities for Strategic Command and the 3K Defense System. Seoul also still depends on the United States for key intelligence, surveillance, and reconnaissance capabilities for the military’s effective operation. These challenges likely spurred greater effort within the alliance, driven by Washington, to tighten conventional-nuclear integration between U.S. and South Korean forces.

South Korea plans to develop or acquire more surveillance satellites and ground-to-ground guided weapons for the Kill Chain; more ballistic missile early warning systems, an L-SAM interceptor system, and a low-altitude missile defence system for the Korea Air and Missile Defense system; and secure more 230-mm multiple launch rocket systems and possibly more U.S.-manufactured ATACMS, upgrade its C-130H transport aircraft, and develop and produce more ballistic missile and land-attack cruise missiles for the Korea Massive Punishment and Retaliation plan. But all this hardware requires resources and time to develop, and it must be integrated into existing organizational force structures and operating concepts.

South Korea faces another related challenge: North Korea’s nuclear and missile threat continues to advance rapidly. As a result, South Korea’s weapons development may not keep up with evolving threats. Seoul and Pyongyang also appear on the precipice of an arms race, which could further destabilize the peninsula.

An additional challenge centres on how effectively such advanced conventional capabilities can be incorporated into the existing software components of the military — in other words, whether the military possesses the necessary organizational, conceptual, and doctrinal innovation and jointness to utilize these advanced capabilities as advertised. Although this challenge was voiced during the beginnings of this current 3K system a decade ago, there still remain outstanding concerns about interservice rivalries and varying doctrinal and technological preferences within the South Korean military.

The Yoon administration is cognizant of the need for South Korea’s military to be more closely integrated and to operate more jointly. A key objective of establishing Strategic Command, according to President Yoon, is “to strengthen the jointness of the three branches of the armed forces and combine and effectively operate the fighting capabilities spread across the services.” The 2022 Republic of Korea Defence White Paper, too, stresses it will be established in stages. The first was in January when South Korea’s Joint Chiefs of Staff expanded its nuclear and weapons of mass destruction response centre to the Directorate of Countering Nuclear and WMD.

The second stage will involve launching the command while establishing operational plans and command and control capabilities, and evaluating and verifying operational capabilities. The command will continue to evolve, the white paper notes, based on changes in the North Korean threat, strategic environment, and South Korea’s own military capabilities.

Seoul’s capability advancements over the last 15 years alongside North Korea’s own steadily advancing nuclear and missile capabilities — and more offensive nuclear doctrine — has provided South Korea with both the means and incentive to realistically envision standing up and operating the new command. Nevertheless, the various challenges above have reinforced the U.S. desire to integrate these capabilities within the alliance.

After all, this command and the 3K Defence System would be activated at the height of the North Korean nuclear or unconventional weapons threat; at the very moment when the highest authority in South Korea would have to make the decision whether to fire missiles at a nuclear-armed neighbour. It likely would operate in a crisis environment in which some form of aggression had already occurred.

The alliance, in fact, may already be at war, albeit still a conventional one. While one of the ultimate purposes of Strategic Command would be to reestablish deterrence within such a conflict — to prevent further escalation up to the nuclear level — it raises understandable concerns on the U.S. side about crisis instability and escalation. Depending on how the ROK operates it, it could spur the very nuclear escalation it is ostensibly meant to deter.

The Washington Declaration’s language around tightening links between South Korean conventional and U.S. nuclear capabilities reflects this persistent U.S. concern. Directly following mention of the Nuclear Consultative Group, the declaration notes the “Alliance will work to enable joint execution and planning for [South Korean] conventional support to U.S. nuclear operations in a contingency and improve combined exercises and training activities on the application of nuclear deterrence on the Korean Peninsula.”

Although the language incorporates Seoul’s demand for greater transparency about U.S. nuclear policy and planning, it demonstrates, too, Washington’s desire to tie as tightly as possible South Korea’s advanced conventional capabilities and its Strategic Command within the Combined Forces Command, the alliance’s bilateral warfighting command structure.

The declaration continues: “President Yoon affirmed that the ROK will apply the full range of its capabilities to the Alliance’s combined defence posture. This includes working in lockstep with the United States to closely connect the capabilities and planning activities of the new Strategic Command and the U.S.-Korean Combined Forces Command. Such activities will include a new table-top exercise conducted with U.S. Strategic Command.” 

The declaration’s language leaves very little doubt that Washington aims to limit just how independent a platform South Korea’s Strategic Command will be moving forward, especially given rumors that South Korean officials are contemplating keeping it outside of the Republic of Korea/United States Combined Forces Command. It is also consistent with the longstanding dynamic between U.S.-imposed constraints and South Korean hedging.

Conclusion

The U.S. government’s concerns about escalation on the Korean Peninsula are not new. However,  these historic concerns have been reinforced by the Yoon administration’s rhetoric regarding preemption, along with North Korea’s nuclear advances and continued tensions on the Korean Peninsula.

South Korea’s Strategic Command is a hedging strategy, designed to ensure that the leadership in Seoul can act promptly during a crisis without interference from the United States. This approach is not necessarily due to a lack of trust in America’s extended nuclear deterrence. Instead, South Korea’s leadership appears to believe it cannot necessarily trust the United States to act quickly during a crisis. For one, U.S. attention and resources could be pulled elsewhere to another contingency. Moreover, given the simple fact that no matter how much deeper the alliance consults within the Nuclear Consultative Group, any possible decision to use nuclear weapons on the Korean Peninsula will be made in Washington by an American leader — current and future.

The constant talk of preemption, however, provides easy justification for North Korea to continually build more nuclear weapons. The result is that both sides may now be incentivized to adopt a “go-first” mentality during a crisis. As Ankit Panda rightly notes, this raises the possibility of North Korean leader Kim Jong Un adopting more dangerous command and control practices in a crisis, like delegating nuclear authority so North Korea’s weapons can be used even if he is incapacitated or killed.

The development of Strategic Command, although understandable, quickens the pace of the decades-old security dilemmas on the Korean Peninsula, narrows the most critical decision-making windows, and crowds out opportunities for diplomacy. The explicit mention of South Korea’s Strategic Command in the Washington Declaration may indicate the alliance is gearing up to navigate these dilemmas in a more mature manner. The urgency of the environment certainly requires it but also underscores just how fragile the current status quo is on the peninsula.