[Trump's Second Term and Korea's Nuclear Option] ② Cost-Benefit Analysis of Korea's Nuclear Armament Option and Demand for Civilian Enrichment and Reprocessing

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I. Growing Demand for Nuclear Armament in Korea

In various opinion polls over the past few years, the support rate for indigenous nuclear armament among the Korean public has hovered around 70%. This is a remarkably high figure, especially when compared to Japan, where public support for nuclear armament is below 20%. An Asan Institute for Policy Studies poll (May 2022) revealed that 63.6% supported nuclear armament even with the possibility of sanctions, indicating a firm public consensus on indigenous nuclear armament (Asan Institute for Policy Studies 2022).

Koreans are generally understood to desire nuclear armament due to the threat from North Korea, in other words, for 'security' reasons. Arguments such as "Nuclear weapons can only be deterred by nuclear weapons" and "We must arm ourselves with nuclear weapons because we cannot trust the US nuclear umbrella" fall into this category. However, the motivations behind public support for nuclear armament in Korea are complex. The aforementioned Asan poll shows that when asked about the reasons for supporting nuclear armament, 32.1% chose "To respond to North Korea's nuclear threat," 33.7% chose "To establish nuclear sovereignty as a sovereign nation," and 33.4% chose "To increase international influence as a nuclear-armed state."

These figures indicate that Koreans place significant importance on 'prestige' among the three main motivations for nuclear armament (security, politics, prestige). Since the indefinite extension of the Nuclear Non-Proliferation Treaty (NPT) in 1995 after the Cold War, negative perceptions of nuclear weapons—as anti-peace, anti-humanity, and anti-environment due to their indiscriminate mass destruction and permanent environmental damage—have spread widely, particularly within civil society. However, contrary to this global trend, anti-nuclear sentiment has not gained significant traction within Korea.

Why do Koreans support nuclear armament? In fact, the high interest and support for nuclear weapons among Koreans predates the era of North Korea's nuclear armament. Korea is a 'small to medium-sized country' in terms of national scale and a 'sandwiched nation' geopolitically, surrounded by great powers. Ultimately, the Korean Peninsula was divided due to great power politics, and since its founding, Korea has constantly suffered from the influence of surrounding powers and the security threat from North Korea. During the Cold War, Korea allied with the nuclear superpower, the United States, for national survival, opting for the nuclear umbrella instead of nuclear armament, partly voluntarily and partly by coercion, and joined the NPT. Since then, Korea has been able to focus on political and economic development under the protection of the US nuclear umbrella and has emerged as a leading global middle power in the post-Cold War era. Due to the characteristics of being a small to medium-sized country and a sandwiched nation, and the historical experiences stemming from this, Koreans tend to aspire to be a 'great power.' The public opinion poll results on the motivations for nuclear armament among Koreans align with this perception.

In the case of North Korea, it appears to have chosen nuclear development as a self-help measure after the collapse of its traditional sponsor, the communist bloc, and the intensification of internal security and regime crises in the post-Cold War era. When North Korea finally succeeded in developing nuclear weapons in the late 2010s, Korea stood at a crossroads, facing the choice of whether it too should arm itself with nuclear weapons to counter the North Korean nuclear threat. According to traditional nuclear strategy knowledge, "nuclear weapons must be countered with nuclear weapons." If Korea were in an anarchic international order of the law of the jungle and did not have nuclear-armed great powers as allies, it would have no choice but to pursue nuclear armament, braving all sorts of international sanctions and pressure.

However, Korea possesses a nuclear superpower as its ally, the strongest in the world, and has achieved economic development and emerged as a global trading nation under the protection of this alliance. Furthermore, after abandoning nuclear development and joining the NPT regime, it has grown into a world-leading nation in the peaceful use of nuclear energy. Therefore, the question arises: should Korea abandon these achievements for nuclear armament?

The aforementioned Asan Institute for Policy Studies poll results exemplify the strong will of Koreans for nuclear armament. However, there are other poll results as well. According to the Korea Institute for National Unification's 2023 annual opinion poll, when asked whether they would pursue nuclear armament while accepting its side effects (economic sanctions, damage to alliances, etc.), the support rate dropped to about 35%. This statistic indicates that public support for nuclear armament can significantly fluctuate depending on the political and economic costs of nuclear armament.

II. Fallacies of the Indigenous Nuclear Armament Argument

This paper argues that the domestic argument for nuclear armament unrealistically overestimates the uncertain benefits of nuclear armament and Korea's capacity for nuclear weapon development, while significantly underestimating the effectiveness of US non-proliferation policies, the international non-proliferation regime, and sanctions.

First, the nuclear armament argument posits that "Korea can legally withdraw from the NPT under Article X and develop nuclear weapons." However, if Korea were to actually initiate the process of withdrawing from the NPT, it would face strong criticism and threats of sanctions from major international organizations and countries, including the UN Security Council, IAEA, the United States, Japan, EU nations, and China. If Korea were to actually withdraw from the NPT and proceed with nuclear development, it would likely face not only threats of sanctions but also a wide range of practical multilateral and bilateral sanctions.

Even if Korea were to withdraw in accordance with the procedures stipulated in Article X of the NPT, the UN Security Council and major stakeholders would likely actively impose sanctions citing reasons such as world peace, regional stability, and national security. In such a scenario, Korea would instantaneously fall from its international status as an advanced nation, a middle power, a non-nuclear peaceful state, a model NPT member, and a model state for nuclear energy utilization, to that of a nuclear proliferator, a violator of international norms, and a rogue state.

Second, the nuclear armament argument claims that "the US will tacitly accept and eventually approve of Korea's nuclear armament." This assertion overlooks the reality of international politics, where Korea cannot simultaneously possess indigenous nuclear armament and the ROK-US alliance (nuclear umbrella). Furthermore, this argument disregards the historical experience where the US government has consistently upheld its non-proliferation principles and thoroughly blocked Korea's access even to enrichment and reprocessing for peaceful purposes. Since its first nuclear test in 1945, the US has sought to curb the nuclear development of other countries, and after the NPT entered into force in 1970, it pursued an even stricter non-proliferation policy. Specifically, it demanded and enforced the abandonment of independent nuclear armament by its allies in exchange for providing the nuclear umbrella. Concerned about nuclear development, it has opposed new countries acquiring enrichment and reprocessing technology since the mid-1970s. In Korea's case, the US was particularly concerned that the introduction of new enrichment and reprocessing technology could lead to regional nuclear proliferation, regional instability, and an arms race, thus strictly blocking access to such technology.

Recently, some US figures have made statements seemingly condoning Korea's nuclear armament, leading to speculation about the possibility of the Trump administration allowing it. However, these statements were made by former officials, and the likelihood of the Trump administration agreeing to, or even tacitly accepting, Korea's nuclear development is virtually zero. Even if the Trump administration were to adopt a somewhat tolerant stance towards nuclear proliferation, subsequent administrations are highly likely to revert to strict non-proliferation principles.

Third, the nuclear armament argument asserts that "Korea possesses the capability for rapid nuclear development." President Yoon Suk-yeol himself stated, "If we decide to pursue nuclear armament, we have the technological foundation to achieve it in a short period, even within a year" (April 2023). However, given that research in this area has been prohibited domestically since the US banned access to enrichment and reprocessing technology in 1975, and that there are no relevant experts, achieving nuclear development within a year is an entirely unrealistic scenario. For Korea to independently develop nuclear weapons, it would have to start by developing enrichment or reprocessing technology and constructing new facilities, a process that experts commonly estimate would take at least three to five years.

Fourth, the nuclear armament argument contends that "economic sanctions must be endured for national survival through nuclear armament." However, the economic and diplomatic hardships that international sanctions can inflict are readily apparent from the cases of North Korea and Iran, raising doubts about whether Korea could withstand such sanctions. No country, except for North Korea with its highly closed, self-reliant, and self-sustaining political and economic system, has successfully pursued nuclear development while enduring international sanctions. Moreover, as a typical open trading nation, Korea is exceptionally dependent on external trade and is therefore more vulnerable to sanctions than any other country.

Fifth, the nuclear armament argument claims that "the US 'torn nuclear umbrella' cannot be trusted, and only 'self-reliant nuclear power' can achieve 'nuclear peace' between the South and the North." However, Korea's nuclear armament would likely exacerbate its security situation. If Korea were to arm itself with nuclear weapons, the ROK-US alliance would be significantly weakened, and the possibility of withdrawing US forces from Korea could arise. It is questionable whether the value of Korea's nuclear armament outweighs the value of the ROK-US alliance (nuclear umbrella and US troop presence).

The ROK-US alliance and the US nuclear umbrella have been highly effective in ensuring Korea's security, particularly in deterring North Korean aggression and preventing war. During the Cold War, the US faithfully provided security commitments and the nuclear umbrella to its allies, even in the face of overwhelming nuclear threats from the Soviet Union. As North Korea's nuclear armament has become a reality and its nuclear threats have increased, the US has further strengthened its extended deterrence by establishing the Nuclear Consultative Group (NCG) and making the deployment of strategic assets more visible.

Furthermore, the case of India and Pakistan demonstrates that even with mutual nuclear deterrence, large-scale military conflicts have occurred frequently, and the risk of nuclear use has persisted. As divided nations, South and North Korea are engaged in an extreme zero-sum security competition, aiming for the complete elimination of each other—a more precarious situation than the security competition between India and Pakistan. Therefore, even if Korea were to arm itself with nuclear weapons, it is feared that the resulting nuclear deterrence relationship would be highly unstable and dangerous, falling short of the mutual deterrence achieved between India and Pakistan, let alone the mutual deterrence between the US and Russia.

III. Critique of the 'Nuclear Potential' Argument and the So-Called 'Japanese Model'

Some politicians and experts advocating for indigenous nuclear armament, considering the practical difficulties, propose acquiring enrichment and reprocessing capabilities as a fallback option to possess 'nuclear potential.' The nuclear option they aim for is the so-called 'Japanese model,' which involves possessing enrichment and reprocessing capabilities. While this argument for 'nuclear potential' may appear more prudent and rational than the indigenous nuclear armament argument at first glance, it remains undesirable and highly unrealistic in Korea's current foreign policy and security context.

First, there are significant differences between Korea and Japan in the history and capabilities of their nuclear power programs. As early as the 1950s, the Japanese government decided to maximize the utilization of nuclear power to enhance its vulnerable energy security and invested heavily in the development of a closed nuclear system based on plutonium and fast breeder reactors, which were then considered an inexhaustible energy source. As a result, Japan had already acquired enrichment and reprocessing technology by the 1960s and began operating its first nuclear power plant in 1966.

In 1974, after India conducted a nuclear test using plutonium extracted from its peaceful nuclear program, the US government began to strictly block the transfer of enrichment and reprocessing technology to countries that did not already possess such facilities, in order to prevent further nuclear proliferation. However, Japan, having already possessed enrichment and reprocessing facilities and technology, was excluded from the US prohibition on enrichment and reprocessing cooperation. Although the US later attempted to apply strict non-proliferation policies to Japan, it ultimately acknowledged Japan's vested rights by granting comprehensive prior consent for Japan's enrichment and reprocessing activities in the 1988 US-Japan Nuclear Agreement.

In contrast, Korea, a latecomer to nuclear power, missed the opportunity to acquire additional enrichment and reprocessing technology due to the US strengthening its non-proliferation policy after India's nuclear test in 1974. Under the ROK-US Atomic Energy Agreement signed in 1974, Korea was required to obtain US "prior consent" for enrichment and reprocessing. In this context, "prior consent" was effectively a euphemism for prohibition. Even in the revised ROK-US Atomic Energy Agreement of 2015, Korea failed to obtain prior consent for enrichment and reprocessing, and consequently, related nuclear activities remain prohibited.

Second, the US has viewed Korea and Japan differently in terms of non-proliferation credibility. The US perceives Japan as a country with a low possibility of nuclear proliferation, while it views Korea as having a relatively higher possibility. Japan has earned international trust in non-proliferation by maintaining its "three non-nuclear principles (no possession, production, or introduction of nuclear weapons)" since 1967. Japan's status as the only country to have suffered atomic bombings, the prevalence of anti-nuclear sentiment among its citizens, and its consistently low support rate for nuclear armament (below 20%) also serve as grounds for its high non-proliferation credibility.

Third, the US perception of the impact of Korea's and Japan's respective nuclear options on regional security also differs. The US views Japan's possession of enrichment and reprocessing capabilities as a deterrent to nuclear armament desires and as a factor in maintaining strategic stability and balance in Northeast Asia. Furthermore, Japan's enrichment and reprocessing capabilities are managed under the strict control and surveillance of the US and are seen as strengthening the US-Japan alliance. On the other hand, the US views Korea's enrichment and reprocessing as negatively impacting regional arms races and nuclear proliferation, and potentially even escalating the risk of war. Moreover, the US is concerned that if Korea were to possess nuclear potential and nuclear options, it might pursue independent foreign and security policies and deviate from the ROK-US alliance.

For these reasons, the US has opposed Korea's attempts to acquire enrichment and reprocessing capabilities and is unlikely to change its stance for a considerable period. The US has consistently rejected Korea's demands for industrial and civilian enrichment and reprocessing on the grounds of nuclear proliferation risks. If Korea were to demand enrichment and reprocessing for the purpose of 'nuclear potential,' the US would not only oppose it but also likely intensify its monitoring of all of Korea's nuclear activities in conjunction with the IAEA.

IV. Korea's Pursuit of Civilian Enrichment and Reprocessing and the Non-Proliferation Conditions Therefor

In the current era of climate change, geopolitical competition, and the AI revolution, all nations are striving to achieve both enhanced energy security and a stable supply of carbon-free energy. As fossil fuels such as coal, oil, and gas are likely to be phased out by 2050 to achieve carbon neutrality, the timely and sufficient supply of carbon-free energy has become not just an issue of energy security but also of economic and national security. While renewable energy receives the most attention for carbon neutrality and energy security, nuclear power is emerging as a key carbon-free energy source for countries like Korea, where large-scale supply is hindered by geographical and climatic constraints.

Currently, nuclear power is generating a total of 413 gigawatts of electricity in 32 countries worldwide. According to the International Energy Agency (IEA) report "Nuclear Power and Secure Energy Transitions" (June 2022), the expansion of nuclear power is inevitable as a transitional measure to smoothly transition from the current fossil fuel era to a carbon-free energy era. Nuclear power, in particular, is evaluated as having significant potential as a transitional energy source due to its advantages in dispatchability and scalability compared to renewable energy (International Energy Agency 2022).

Due to its scarcity of energy resources, Korea has invested heavily in nuclear power from an early stage. As a result, it has grown into the world's fifth-largest nuclear power generating country and a nuclear power exporter. However, Korea has a critical weakness in ensuring the continuous utilization of nuclear power: the absence of enrichment and reprocessing capabilities. Among major nuclear power utilizing countries, Korea is unique in not having enrichment and reprocessing facilities and being blocked from accessing related technologies. Consequently, Korea's nuclear fuel supply stability and energy security are highly vulnerable. Even in nuclear power exports, Korea's export competitiveness is diminished compared to other exporting countries due to the lack of guaranteed nuclear fuel supply and reprocessing services.

Currently, the supply of nuclear fuel is monopolized by a very small number of advanced nuclear power countries and nuclear-armed states. Uranium enrichment is monopolized by four companies: Rosatom of Russia (40%), CNNC of China (12%), Urenco of the UK, Germany, and the Netherlands (27%), and Orano of France (14%). When a small number of countries and corporations dominate the global enrichment market, there is a high probability that they will weaponize enrichment supply in the event of escalating geopolitical conflicts.

Indeed, following the outbreak of the war in Ukraine (2022), the US and Western countries recognized the vulnerability of their energy security due to excessive reliance on Russian enriched uranium supplies and began to expand their enrichment capabilities. The US Congress even passed the Prohibiting Russian Uranium Imports Act, banning imports of Russian uranium from 2028. In response, Russia threatened to halt nuclear fuel exports to the US and Western countries. Since the war in Ukraine, the global nuclear fuel supply market has rapidly realigned into the Western bloc, comprising the 'Sapporo 5' (US, Western Europe, Japan), and the anti-Western bloc, consisting of Russia and China.

Korea currently relies on Russia for approximately 30% of its enriched uranium imports. If US-Russia competition intensifies further and the US achieves self-sufficiency in uranium enrichment, it is expected that the US will demand that its allies cease purchasing Russian enriched uranium. There is even a possibility that Russia may preemptively halt enriched uranium exports. The US is significantly increasing investment in its own enrichment facilities, and Western nuclear-utilizing countries are expanding their enrichment capabilities by forming the 'Sapporo 5.' If Russian enriched uranium can no longer be purchased in the international nuclear fuel market, it is evident that Korea will be the biggest victim.

The damage is not limited to the threat to the stable and continuous operation of large-scale nuclear power plants. Currently, there is fierce global competition for the development of Small Modular Reactors (SMRs) for future nuclear power, but Korea's development of advanced SMRs is significantly delayed due to its lack of enrichment and reprocessing technology. Even if SMRs are developed in the future, Korea is at high risk of falling behind in the SMR era for a considerable period due to its inability to procure advanced nuclear fuels such as High-Assay Low-Enriched Uranium (HALEU) or Transuranic (TRU) fuel for SMRs.

To prepare for such contingencies, the ROK-US presidents agreed in 2022 to "jointly cooperate to secure energy supply chains, including enriched uranium," and the joint statement of the ROK-US-Japan summit in Camp David in 2023 declared that they would "accelerate the reduction of dependence on Russian energy." However, there has been no progress in government-level consultations and cooperation on this matter.

In addition, Korea faces a serious issue with the management of spent nuclear fuel. Some countries directly dispose of spent nuclear fuel, but major nuclear powers such as France, Russia, Japan, India, and China have all chosen reprocessing and recycling policies. Korea is temporarily storing spent nuclear fuel on-site at nuclear power plant locations while exploring recycling or direct disposal. Even if the direct disposal method is chosen, treatment is necessary to reduce the volume and toxicity of the waste to facilitate disposal. Alternatively, reprocessing or pyroprocessing is required to produce TRU fuel for SMRs. As the US opposes wet reprocessing due to its high proliferation risk, Korea is developing pyroprocessing technology, a form of reprocessing with lower proliferation risk, as an alternative.

In the past, Korea's attempts to acquire enrichment and reprocessing capabilities have repeatedly been frustrated by the US government's opposition. The main justifications cited by the US for opposing Korea's enrichment and reprocessing are as follows: First, Korea voluntarily abandoned the possession of enrichment and reprocessing facilities in the 'Joint Declaration on the Denuclearization of the Korean Peninsula.' Second, if the US allows enrichment and reprocessing in Korea, it loses its justification for opposing it in other countries. Third, the objective necessity and economic feasibility of Korea's enrichment and reprocessing are questionable. Fourth, Korea's possession of enrichment and reprocessing capabilities would negatively impact North Korean denuclearization diplomacy. Fifth, Korea has low non-proliferation credibility due to its past attempts at nuclear development and the high public support for nuclear armament. In summary, the US has opposed enrichment and reprocessing to block Korea's path, fearing its nuclear development.

Therefore, if Korea is to introduce enrichment and reprocessing for sustainable nuclear energy and energy security, it must first address these US concerns about nuclear proliferation. To pursue civilian enrichment and reprocessing, it is a prerequisite to foster a non-proliferation atmosphere domestically and to lower the high public support for nuclear armament. To this end, I propose that the Korean government establish a 'National Enrichment and Reprocessing Policy' as part of its peaceful use and industrial nuclear policy. This policy should include the purpose and necessity of enrichment and reprocessing, consensus among stakeholders and national will regarding its introduction, the schedule and scale of its introduction, reaffirmation of national non-proliferation commitment, and measures to enhance nuclear transparency. In addition, objective and persuasive counterarguments should be developed and implemented against the US rationale for opposing Korea's enrichment and reprocessing.■

V. References

Asan Institute for Policy Studies. 2022. “South Koreans and Their Neighbors.” June 8. https://www.asaninst.org/contents/south-koreans-and-their-neighbors-2022/

Yoon Suk-yeol. 2023. “President Yoon Suk Yeol's Address at Harvard University.” The Presidential Office of the Republic of Korea. April 28. https://www.president.go.kr/president/speeches/UWTpwQnG

IEA. 2022. “Nuclear Power and Secure Energy Transitions.” June. https://www.iea.org/reports/nuclear-power-and-secure-energy-transitions

■ Jeon Bong-keun, Professor Emeritus, Korea National Diplomatic Academy

■ Contact and Editing:Kim Chae-rin, EAI Research Assistant

    Inquiries: 02 2277 1683 (ext. 208) | crkim@eai.or.kr