North Korea does not necessarily need to start a nuclear war to benefit from its nuclear arsenal. Instead, Pyongyang could use the increasing possibility of nuclear escalation to threaten South Korea, undermine its alliance with the United States, limit Seoul’s available military options, and extract political concessions in a crisis situation.
Preventing such nuclear blackmail requires more than threatening retaliation. South Korea should prove that neither a limited nuclear attack nor the threat of one could paralyze its government, destroy its warfighting capability, or separate it from its allies.
A largely forgotten French debate from 1954 offers a useful historical reference case. Faced with the Soviet nuclear threat and uncertainty about how credible US extended nuclear deterrence would be, French Prime Minister Pierre Mendès France considered relocating important weapons production facilities from metropolitan France to Algeria, according to Henry Kissinger’s Leadership: Six Studies in World Strategy. The logic was plain and simple: French military force would have almost no value if France’s industrial foundations were destroyed in the initial stages of war.
This proposal was never fully implemented, and French Algeria was far from a stable or politically sustainable sanctuary. Nevertheless, the case offers an invaluable lesson. Nuclear deterrence depends not only on the capability to retaliate but also on the ability to withstand the enemy’s first blows.
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France’s Search for Strategic Depth
In 1954, France was recovering from the Second World War, encountering defeat in Indochina, and reconsidering its status within the Western alliance. Most of France’s population and industrial capacity were concentrated in metropolitan France and therefore vulnerable to Soviet bomber attack—by 1954, the Soviets had roughly 1,000 long-range Tu-4 bombers. The French leadership could not assume that conventional arms and the US commitment alone would ensure the nation’s survival.
Mendès France’s contemplation of transferring weapons factories to Algeria reflected an early form of strategic dispersal. North Africa appeared to provide distance, territory, and alternative industrial centers. At the time, Algeria was legally considered part of France, yet geographically separated from European battlefields.
The proposal included three distinctive assumptions.
First, strategic assets should not be concentrated in areas where they could be destroyed by the enemy simultaneously. Second, arms production should continue even after the first wave of attack. Third, national strategy should be prepared for the possibility of allied reinforcement being either delayed, limited, or politically contested.
The Mendès France government also began institutional measures—most notable the creation of a nuclear explosives committee and a research and design center in 1954—that later contributed to France’s nuclear program. France eventually came to the conclusion that an independent capability for retaliation and national resilience was a necessity, since fully relying on another country’s nuclear decision would be inherently uncertain.
Although South Korea is situated within a different political and technological environment, the fundamental question is increasingly becoming similar.
The Growing Problem of American Credibility
US extended deterrence remains crucial to South Korean security. Nonetheless, North Korea is trying to weaken the trustworthiness of US extended deterrence by increasing the potential cost of US intervention. Worryingly, recent wargames indicate that the US might not retaliate in kind if North Korea strikes South Korean military targets with tactical nuclear weapons.
Missiles with longer ranges, such as Hwasong-18, allow Pyongyang to directly threaten US territory. A larger nuclear stockpile would enable North Korea to use some of its weapons against Japan or South Korea while reserving others for the United States. Meanwhile, the miniaturization of nuclear warheads would permit nuclear weapons to be loaded onto a wider variety of delivery systems. Once North Korea secures a reliable multiple independently targetable reentry vehicle (MIRV) capability, it would ultimately deploy both multiple warheads and penetration aids—even with a relatively limited number of missiles—against the American missile defense network.
This does not mean that the United States would abandon South Korea. Rather, it implies that North Korea might increasingly believe it can create sufficient uncertainty about the American response.
Pyongyang could threaten to strike an American city if Washington intervened after a limited attack against South Korean military targets. Also, North Korea could threaten Japan in order to constrain the use of US bases in Japan. North Korea would attempt to separate three decisions: whether South Korea should resist; whether Japan should assist US operations; and whether the US should risk military escalation on behalf of its regional allies.
North Korea’s 2022 Nuclear Law further deepens the danger. The law regulates a broad range of circumstances under which nuclear weapons could be used while providing that a nuclear strike may be automatically launched if Pyongyang’s nuclear command system is on the verge of collapse. Although these provisions are partially intended to deter decapitation operations, they could also impose restraint on American and South Korean leaders in a fast-paced crisis situation.
Missile Defense Is Needed but Insufficient
South Korea’s Three-Axis System is designed to seamlessly align the Kill Chain concept, Korea Air and Missile Defense (KAMD), and Korea Massive Punishment and Retaliation (KMPR). However, the system has not been completed.
KAMD cannot guarantee the interception of all ballistic missiles, cruise missiles, or low-flying delivery platforms. To overwhelm South Korean detection and command systems, North Korea can combine missiles, drones, electronic warfare, cyberattacks, decoys, and sabotage. Furthermore, North Korean launchers could be dispersed, concealed, or deployed in hardened facilities.
South Korea should continuously improve KAMD, but its strategy should not be built upon the premise that every nuclear delivery system would be either destroyed before launch or intercepted during flight. No missile system can offer comprehensive defense against a growing and diversified nuclear force.
The 1950s French lesson is that defense should begin with the assumption that some attacks would penetrate the defense network.
Structuring a Dispersed South Korean Defense System
As a priority, South Korea should disperse facilities that are critical to sustaining military operations. Strategic command posts, communication nodes, missile bases, and maintenance facilities should not be concentrated in a small number of known locations.
If major command posts are decimated, alternate ones should immediately assume responsibility. Military communications should combine hardened fiber networks, satellites, mobile systems, and alliance communication channels. Authority over necessary defense operations should be sufficiently delegated to prevent command paralysis without creating the risk of uncontrolled escalation.
Second, South Korea should develop distributed defense-production capacity. To be sure, arms production factories cannot be relocated to a different continent, as Mendès France considered doing. Nevertheless, Seoul could still create geographically separated production lines, safeguarded component reserves, and emergency conversion plans for civilian industry.
The key objective should not be to replicate every major factory. A more realistic aim would be to ensure the uninterrupted production and maintenance of missile defense systems, UAVs, precision-guided munitions (PGMs), spare parts, communication devices, and artillery shells, even after a large-scale attack.
Third, South Korea needs much larger wartime reserves. Industrial production capability matters only when production can continue, while production inevitably requires time. Hence, the volume of reserves, such as missile interceptors and PGMs should be calculated against a prolonged campaign rather than the initial few days of the war.
Civil defense should also be part of deterrence. Hardened evacuation facilities, protected emergency medical capacity, redundant electricity and water systems, evacuation plans, and reliable public-warning systems would all reduce North Korea’s ability to generate political chaos. It would be difficult to blackmail a population that expects state functions to remain intact even after a massive attack.
Strategic Depth Through Alliances
South Korea lacks geographical depth, but alliances could provide functional depth.
The United States, Japan, and South Korea should construct a distributed regional support network. Maintenance facilities, ammunition depots, intelligence-processing facilities, logistics facilities, and some command functions can be dispersed across the continental United States, Guam, Japan, and South Korea. In that case, North Korea would not be able to neutralize the alliance’s capacity to respond by attacking a limited number of areas within South Korea.
Japan is especially important. US bases in Japan are crucial for reinforcement operations, surveillance, logistics, and air power. Therefore, Tokyo should reinforce and disperse its military facilities, expand runway-repair capabilities, protect fuel and ammunition storage facilities, and prepare civilian ports and airports for emergency support.
The three countries should conduct joint exercises that begin after simulated nuclear strikes rather than ending when one occurs. They should test leadership succession, degraded communications, damaged ports, disconnected satellite links, massive casualties, and continued conventional operations under nuclear conditions.
Last but not least, Washington should make the consequences of limited nuclear use clearer. Since every president would preserve his or her control over nuclear decisions, absolute automaticity may be nearly impossible. Nonetheless, ambiguity should be strictly limited to the specific form and scale of retaliation, not to whether North Korea’s nuclear use would activate a decisive allied response.
The United States and South Korea should jointly convey to Pyongyang that any nuclear attack would be unsuccessful in terminating disputes, disrupting the alliance, or preserving North Korea’s military gains.
Denying Nuclear Blackmail
North Korea’s most dangerous assumption would be that one or two nuclear blasts could shock South Korea into accepting an armistice before the alliance could take countermeasures. To defeat this premise, it is essential to have the ability to absorb damage, maintain political control, continue military operations, and introduce allied forces into the fray.
Mendès France’s 1954 proposal was shaped by colonial circumstances that cannot and should not be replicated. However, its strategic logic stands. Countries that are exposed to nuclear attack need to think beyond interception and retaliation. They should protect the institutions, industries, and alliances that would enable continuous resistance when initial deterrence has failed.
North Korea would be less likely to attempt nuclear blackmail when its leadership fully grasps that deploying nuclear weapons would not eliminate South Korean forces, isolate South Korea, or terminate allied resistance. Therefore, for Seoul, resilience is not merely preparation for war. It is a quintessential means of preventing war.
