South Korea’s Offensive Military Strategy and Its Dilemma

For the last two months, Kim Jong-un declared that unification with South Korea was no longer feasible, and ordered to dismantle all organizations involved in engagement with South Korea. These significant shifts in North Korea’s stance toward South Korea sparked an intense debate on Pyongyang’s intentions among North Korea watchers. Yet, little attention has been paid to South Korea’s offensive military strategy and its impact on the security dynamics of the Peninsula. 

In October 2023, the newly appointed defense minister Shin Won-sik summarized South Korea’s offensive strategy as “PISU: Punish Immediately, Strongly, and Until the end (즉각강력히, 끝까지 응징)”, if provoked by North Korea. South Korea’s offensive strategy aims to deter North Korea’s aggression, not to initiate an attack against North Korea. However, it is uncertain whether Pyongyang fully understands Seoul’s defensive intent as well as its firm resolve to counterattack. Similarly, it remains unclear how Seoul intends to manage the escalating risks exacerbated by its own offensive approach. To maintain stability on the Korean Peninsula, it is vital to understand the origin of South Korea’s offensive strategy, its intended effects, and dilemma. 

The Origin and the Logic of South Korea’s Offensive Military Doctrine 

As outlined in the 2022 defense white paper, the South Korean military has formulated a strategy known as the "three-axis system." It consists of (1) the "Kill Chain" platform, which involves preemptive strikes targeting North Korea's nuclear and missile facilities upon clear indicators of their intended use, (2) the Korea Air and Missile Defense (KAMD) system, and (3) the Korea Massive Punishment and Retaliation (KMPR) plan, which includes precision missile attacks or infiltration of special operation forces to eliminate the North Korean leadership. The three-axis system embodies South Korea's offensive posture, featuring preemptive and retaliatory strike capabilities.

South Korea's military strategy has become increasingly offensive over the past decade. In the 2012 defense white paper, preemptive or retaliatory strikes were not included as part of South Korea's military strategy. In February 2013, the Ministry of Defense introduced the "Kill Chain" strategy, marking a significant departure. Subsequently, the Park Geun-hye administration unveiled the KMPR strategy in September 2016. These offensive shifts caused concerns among scholars regarding legality. According to an Asan Institute report, while the Kill Chain strategy may meet the conditions of self-defense, such as the imminency of an enemy attack or proportionality of preemptive action (if the strike is limited to the launching point of the imminent attack), justifying the ‘massive retaliation’ aspect of KMPR strikes could be challenging due to its disproportionality. 

Why so offensive? First and foremost, it reflects South Korea’s desperate need to deal with an increasingly nuclear-capable North Korea. South Korea represents one of few cases where a non-nuclear state has to rely on advanced conventional capabilities to deter a nuclear-armed adversary. South Korean strategists are concerned that Pyongyang may be emboldened to take military actions against South Korea whenever it deems necessary, due to its increasing confidence in nuclear deterrence against the United States and South Korea. Even worse, it cannot be ruled out that North Korea may use nuclear weapons first for coercive purposes. Therefore, South Korea needs to maximize its deterrence to make North Korean leaders think twice before taking such actions against South Korea. 

South Korea’s offensive strategy aims to achieve this goal with two distinct approaches: automaticity and personalization of threat. First, the principle of PISU reflects South Korea’s resolve to counteract automatically. By publicly stating this policy, South Korea signals that it has “burned the bridges behind” and will retaliate without hesitation, if attacked by North Korea. Second, the threat of retaliation is personalized to target North Korean leaders, including Kim Jong-un. The former and current defense ministers have repeatedly emphasized that South Korea’s special operation forces are well-trained to infiltrate North Korea to assassinate its leadership. Once again, by publicly stating this policy, Seoul appears to signal a message, specifically tailored to North Korean leaders, like this: "You may succeed in destroying our cities and people with your nuclear weapons, but rest assured, we will find you and kill you.”

The Danger and Dilemma 

The problem is that if these threats fail to deter Pyongyang, the dangerous situation can quickly spiral out of control. One can consider simulating a contingency like the Yeonpyeong Island shelling. On November 23, 2010, North Korea fired approximately 100 artillery rounds at South Korea’s Yeonpyeong Island. The sudden attack killed two South Korean marines and two civilians, injuring 16 South Korean citizens. According to the memoir of Lee Dong-kwan, a senior official serving in the Lee Myung-bak administration, two F-15s flew to Yeonpyeong Island. During a press interview before retirement, President Lee stated that he ordered the aircraft to bomb the North Korean bases, but South Korean generals advised that such an action required consultation with the U.S. Forces Korea. 

In 2024, if the South Korean military faces a similar situation, it will retaliate "immediately, strongly," and "until the end" against the commanding post of the North Korean forces that initiated such an attack. However, since South Korean leaders talked so much about leadership decapitation, North Korean leaders might misperceive that a regime-ending strike is imminent. Such a perception would drive Pyongyang’s decision to use nuclear weapons preemptively, as codified in North Korea’s nuclear doctrine document. Detecting North Korea’s likelihood of using nuclear weapons, South Korea would activate the "Kill Chain" operation and launch preemptive strikes.|

South Korea’s strategy in response to possible escalation to all-out war is criticized not only by left-wing groups in South Korea, but also by U.S. experts. Keir Lieber and Daryl Press, renowned scholars of nuclear strategy, argue that South Korea should refrain from threatening the survival of the Kim family regime, "thereby reducing the risk that a desperate leader will employ a nuclear weapon." They advise that even if North Korea launches a major attack on South Korea, it would be wise for Seoul to limit its military response to the attacking positions, without continuing the campaign north to Pyongyang. Ankit Panda, a nuclear expert at Carnegie Endowment for International Peace, similarly argues that the escalation risk of South Korea’s overt threats of killing Kim Jong-un significantly outweighs the benefits. He advises that focusing on deterrence by denial, instead of deterrence by punishment, may be an optimal strategy for South Korea.

One missing variable in these analyses is the domestic politics of North Korea: the Kim family may face a threat to regime survival not only from the outside but also from within, which is beyond South Korea’s control. Since external observers lack information about internal affairs, Kim Jong-un’s threat perception of internal challenges remains unknown. To this date, it remains unclear why North Korea conducted such exceptionally belligerent acts as torpedoing the Cheonan or shelling Yeonpyeong Island in 2010. Analysts generally speculate that these actions may have been related to power succession from Kim Jong-il to Kim Jong-un: the Kim family regime sought to bolster the young Kim’s authority and consolidate support among leadership circles. If indeed the Kim family has domestic motives for military provocations unknown to outside observers, South Korea’s less offensive posture can make Pyongyang's aggression even more likely.

For this reason, South Korea needs to maintain its offensive strategy as simple as possible. Thomas Schelling explained that deterrence is, in essence, designed to present an option to an adversary: “I can block your car on the road by placing my car in your path; my deterrent threat is passive, and the decision to collide is up to you.” Following this analogy, one can argue that South Korea places its offensive strategy on the road so that North Korean leaders feel less free to hit South Korean people with its weapons. In other words, the automaticity and simplicity of South Korea’s offensive strategy are designed to assist North Korean leaders in avoiding overthinking and miscalculation. Whether for external objectives or internal reasons, Kim Jong-un should remember that his gain cannot outweigh the ultimate cost of his own death. In this context, Defense Minister Shin Won-sik’s simple message— “punishment is deterrence, and deterrence is peace”—makes sense.

Overcoming the Dilemma

For those concerned about escalating risk, the good news is that both South and North Korea’s offensive doctrines are conditional. As Professor Moon Chung-in points out, Kim Jong-un’s threat of occupying South Korea was presented with conditional phrase, "if we are compelled to fight a war." Similarly, South Korea’s resolve of retaliation comes after the phrase, "if provoked by North Korea." This observation suggests that both Koreas are barking out of fear of being attacked first, rather than having the ambition to strike first. In this context, South Korea’s intent with its offensive strategy is defensive in nature. South Korean strategists aim to convey, "we will kill you if you use nuclear weapons,” which also implies that “but we will not if you do not.” The challenge, then, is how to clearly communicate this irony of defensive intent behind offensive rhetoric to North Korean leadership.

Here, China has a role to play. The Yoon Suk Yeol government has already proposed the “audacious initiative” to provide economic compensation in return for North Korea’s “substantive process for denuclearization.” However, Pyongyang is unlikely to believe the conservative government’s goodwill gesture; rather, it may view the proposal as a conspiracy to facilitate South Korea’s economic absorption of North Korea. Due to the trust deficit between the two Koreas, thought should be given to third-party mediation with China. Although Beijing and Pyongyang have their own trust issues, at least they still meet and talk on a regular basis. On behalf of South Korea, Chinese leaders can convey both credible threats and assurances to North Korean leaders, and China has good reasons to do so.

China’s priority on the Korean Peninsula is to maintain peace and stability, which includes controlling North Korea’s excessively belligerent behaviors. When it was undeniably clear that Pyongyang drove the situation to a dangerous point, Beijing publicly criticized North Korea’s belligerence. For example, when Pyongyang threatened to attack the United States with its nuclear weapons in 2017, the editorial of Global Times, reflecting the viewpoints of Chinese authorities, openly warned that China’s mutual defense treaty does not obligate China to support North Korea if a crisis is initiated by North Korea’s actions first. As such, China and South Korea share a common interest in preventing North Korea’s miscalculation by clearly conveying South Korea’s firm resolve to counterattack. Nonetheless, if China agrees to do so, they will also demand that, to be fair, South Korea should assure that it would be willing to cooperate if North Korea does so.

This is where the Yoon government needs to articulate a compensation deal for North Korea as a way of persuading China to cooperate. As much as it wants Beijing to caution Pyongyang against testing Seoul’s resolve, it should also offer an exit strategy for Pyongyang to return to diplomacy. Creating diplomatic opportunities for Pyongyang is a separate line of effort from military strategy. The South Korean government should shield the defense ministry’s offensive doctrine from domestic and international criticisms. However, the central government does not always have to speak in one voice with the military leadership. As Shelling argues, “military strategy is an art of coercion, of intimidation and deterrence, and it is diplomacy of violence.” South Korea’s offensive military strategy would be most effective when combined with diplomatic efforts to shape Pyongyang’s (and Beijing’s) perspectives to recognize the costs of military confrontation and the benefits of diplomacy.

Dr. Sungmin Cho is a professor at Daniel K. Inouye Asia Pacific Center for Security Studies (APCSS), an academic institute of the U.S. Department of Defense, based in Hawaii.The views expressed in this article only reflect his own views, not those of APCSS or U.S. Department of Defense.

Dr. Sungmin Cho

Sungmin Cho

Professor, Daniel K. Inouye Asia-Pacific Center for Security Studies