[Global NK Commentary] The 3-Stage Denuclearization Theory and the END Proposal: Issues and Limitations of the South Korean Government's Denuclearization Approach

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Introduction[1]

This article examines the impact of conceptual ambiguity in the denuclearization phased approach and the 'END (Exchange–Normalization–Denuclearization) proposal' on policy consistency and deterrence credibility within the inter-Korean policy environment of the latter half of 2025. Despite eight months having passed since the Trump administration's inception and four months since the Lee Jae-myung administration's inception, official inter-Korean and denuclearization strategy documents from both countries are absent, with fragmentary messages from summit remarks, interviews, and domestic and international speeches substituting for policy. Simultaneously, North Korea, at the December 2023 plenary meeting of the Workers' Party of Korea, shifted inter-Korean relations to 'hostile inter-state relations,' and through its Supreme People's Assembly in January 2024, Kim Yo-jong's statements in 2025, and Kim Jong-un's speeches, it has repeatedly confirmed a line that denies the premise of dialogue itself. Amidst these structural changes, a re-examination is necessary to determine whether declarative stage distinctions such as 'freeze–reduction–dismantlement' can drive actual deterrence and negotiation dynamics.

This paper addresses three core questions. First, it assesses the implications of the terminological and conceptual differences between the 'freeze–reduction–dismantlement' and 'interruption–disarmament–complete denuclearization' approaches proposed by the South Korean government for policy choices and mutual verification systems. Second, it examines how the U.S.'s multi-layered missile defense and institutionalization of extended deterrence (NCG), along with the strengthening of homeland defense symbolized by Executive Order 14186 ( 'The Iron Dome for America,' also known as 'Golden Dome'), are asymmetrically intertwined with South Korea's security dilemma, particularly the direct threat from short- and medium-range nuclear forces like the KN-23. Finally, it considers the risk of solidifying North Korea's status as a de facto nuclear-armed state and creating verification gaps by linking 'interruption (stop)' with compensation, given the confirmation of signs of operationalization of tactical systems tested by North Korea on the Ukraine battlefield.

To this end, the analysis utilizes statements by the South Korean President, speeches at the UN General Assembly, interviews, and materials from the Presidential Office. Publicly available U.S. executive orders, defense-related materials, and Congressional Research Service (CRS) reports are also consulted. Official documents and primary reports from North Korea, including those from the Supreme People's Assembly, the Workers' Party of Korea, and the Korean Central News Agency (KCNA), were compared and analyzed.

Threat Environment and Policy Context

The current situation suggests that the South Korean government is presenting unorganized individual statements and fragmented principles rather than a clear set of principles and a coordinated strategy between South Korea and the U.S. Primarily, the South Korean government's perception of North Korea's nuclear threat appears to be oriented towards the U.S. homeland rather than the threats it imposes on South Korea. President Lee Jae-myung, in his remarks at the New York Stock Exchange on September 25 (local time), introduced his summit meeting with President Trump on August 25.[2] President Lee stated that he emphasized three points. First, North Korea has nearly completed the development of intercontinental ballistic missiles (ICBMs), a nuclear weapon capable of striking the U.S. mainland. The implication is that if the U.S. does not immediately begin dialogue with North Korea, its mainland will be threatened, thus necessitating dialogue. Second, North Korea is continuing to produce approximately 15 to 20 nuclear bombs annually and could potentially export them. This again serves as a warning that if North Korea is not deterred, there is a risk of nuclear proliferation to terrorist groups, a matter of extreme sensitivity to the U.S. Third, therefore, he argued that simply halting North Korea's ICBM and nuclear production capabilities ('stop') would yield 'considerable security benefits.' This implies that only Trump possesses the capability and will to halt North Korea, urging rapid negotiation with North Korea. Absent from this discussion is North Korea's existential nuclear threat to South Korea, which poses a grave threat to the security of the Korean Peninsula. Only North Korea's nuclear attack capability against the U.S. mainland, which remains uncertain, was emphasized. While President Lee's emphasis is understood as an attempt to persuade Trump to engage in U.S.-North Korea dialogue, it is insufficient. This is because even if North Korea's capability to strike the U.S. is in its final development stage, the U.S. still has some lead time.

The current Trump administration is fully engaged in confronting China's nuclear buildup and aggressive nuclear strategy. President Trump signed Executive Order 14186, 'The Iron Dome for America,' on January 27, shortly after his inauguration, which was later renamed 'Golden Dome' by Trump.[3] The policy directions presented are (1) deploying and maintaining next-generation missile defense systems, (2) deterring and defending against all foreign homeland aerial attacks, and (3) ensuring secure second-strike capabilities. To this end, the U.S. is strengthening its defense against ballistic, hypersonic, advanced cruise missiles, and next-generation aerial attacks. Specifically, it is accelerating the deployment of space sensor layers for tracking hypersonic and ballistic missiles and developing and deploying space-based interceptors capable of intercepting missiles during their boost phase. Furthermore, it is enhancing terminal phase intercept capabilities to thwart enemy attacks on high-value targets (e.g., cities, civilian areas) and expanding capabilities to neutralize missile attacks during the pre-launch and boost phases. Despite debates about feasibility, it is a fact that the U.S. is establishing a 'multi-layered defense network' to intercept missiles at various stages, including space, ground, and early launch. If this is the case, it is reasonable to conclude that the U.S.'s advanced defense capabilities aimed at China are sufficient to counter North Korea's ICBMs, whose completion is still uncertain. On September 24, the nominee for Chairman of the South Korean Joint Chiefs of Staff testified at his confirmation hearing that North Korea's ICBM 're-entry into the atmosphere capability appears unverified.'[4]

Unlike the U.S., which can be considered virtually secure due to its superior defensive capabilities and formidable offensive power, South Korea is severely exposed to North Korean threats. In May 2019, while inter-Korean negotiations were actively underway and the South Korean Moon Jae-in administration was promoting its Korean Peninsula peace process, North Korea test-fired for the first time a missile capable of striking all of South Korea with a low-yield nuclear warhead, the KN-23, with a range of 690 km. Subsequently, development has continued, and according to a U.S. Congressional Research Service report in May 2025, North Korea has sufficiently tested this missile on the Russia-Ukraine battlefield and confirmed its operational deployment to attack South Korea.[5]

Therefore, during his meeting with Trump, the South Korean President should have emphasized the existential threat posed by North Korea's nuclear weapons to South Korea, rather than the threat to the U.S. mainland, and reaffirmed the U.S.'s extended deterrence commitment. He should have requested the institutionalization of extended deterrence through the 'Nuclear Consultative Group' (NCG), initiated by the previous Biden administration, to proceed as originally planned, and specifically sought security assurances for the Korean Peninsula. The Biden administration had frequently reiterated its commitment that any North Korean nuclear use would result in the end of the regime, through presidential remarks and official government documents.

Denuclearization Phased Approach and North Korea's Position

The 3-stage denuclearization approach proposed by the South Korean government also requires more detailed explanation for each principle. The terminology used has changed several times. Initially, it was freeze, reduction, and dismantlement, but[6] 이 대통령의 타임지 인터뷰에서는 중단(stop), 군축(disarmament), 완전한 비핵화(complete denuclearization)였다가[7] 9월 23일(현지시간) 유엔연설 표현은 중단(stop), 축소(reduction), 폐기(dismantlement)였다.[8] according to Presidential National Security Advisor Wi Sung-rak, it was initially referred to as 'freeze,' but was subsequently adopted as 'interruption' is a more accurate expression.

However, previous agreements signed with North Korea, such as the 1994 Agreed Framework, used the term 'freeze.' In the context of denuclearization, the concept used is 'freeze,' not 'interruption.' 'Freeze' is an official procedure that specifies the object and verifies compliance, whereas 'interruption' is an ambiguous concept. It is unclear whether it means merely stopping production, halting facility operations, or simply stating that nuclear and missile development will not proceed. This conceptual difference is clearly demonstrated in the frequent use of the phrase 'freeze and verify' in non-proliferation and denuclearization documents and analytical papers. For example, a report by the United Nations Institute for Disarmament Research (UNIDIR) explains that 'freeze' includes halting 'all nuclear material production activities,' thereby minimizing the possibility of concealment or diversion and increasing traceability.[9] Unlike a mere declarative interruption, 'freeze' encompasses measures to halt the production, processing, and reprocessing of nuclear materials, and securing verifiability while that state is maintained is key. However, President Lee stated in an interview with TIME magazine that compensation could be offered to North Korea if it agrees to an interruption.[10] Without a specific definition of 'interruption,' it can be interpreted as emphasizing compensation, which ultimately means the lifting of sanctions against North Korea. If such a situation unfolds, North Korea would become a de facto nuclear-armed state in the early stages of denuclearization negotiations, and based on past experience, progress would become nearly impossible thereafter. Negotiations with North Korea have always broken down due to North Korea's failure to properly engage in verification.

Furthermore, as mentioned earlier, Kim Jong-un, General Secretary of the Workers' Party of Korea, clearly articulated 'the present state and compatibility of inter-Korean relations and the principled stand to be maintained in foreign activities' for about 40 minutes in his speech at the Supreme People's Assembly.[11] He clearly expressed his rejection of the South Korean government's '3-stage denuclearization theory,' referring to it as a 'copy of the homework assignment of predecessors who dreamed of our disarmament,' and stating, 'the so-called "3-stage denuclearization theory" of the current ruling power, namely "interruption-reduction-denuclearization," is also a copy plaghaited from the "homework book" of predecessors who dreamed of our armed forces disarmament."

The current administration's North Korea policy concept also requires explanation. The END proposal, an acronym for Exchange, Normalization, and Denuclearization, appears to have a priority and sequence, despite Wi Sung-rak's denial. It is common sense that normalization of relations can only occur after exchanges. Denuclearization is positioned thereafter. Moreover, as reported, Wi Sung-rak explained the END proposal as a 'principle emphasized in the 2018 North Korea-U.S. Singapore Joint Statement,' which would further imply a sequence. The Singapore statement's core contents are (1) establishment of new North Korea-U.S. relations, (2) a durable peace regime on the Korean Peninsula, and (3) denuclearization of the Korean Peninsula. Following the agreement, then-Secretary of State Michael Pompeo visited North Korea and demanded denuclearization. On July 7, North Korea's Foreign Ministry spokesperson issued a statement criticizing that the Singapore agreement had a sequence, and that "only coercive denuclearization demands were presented, which is contrary to the spirit of the talks."[12] Regardless of South Korea's denial, North Korea insists on a sequence. If South Korea desires improved relations with North Korea, denuclearization must either be de-emphasized or omitted altogether for North Korea to have even a slight chance of responding. In this case, the significantly reduced emphasis on denuclearization could further endanger South Korea's security.

Policy Recommendations and Conclusion

A more realistic assessment is that North Korea is highly unlikely to engage with South Korea in the foreseeable future. Kim Jong-un's speech at the Supreme People's Assembly and Kim Yo-jong's statements confirm this. North Korea, at the 8th Party Congress, 9th Plenary Meeting in December 2023, already finalized its policy of declaring inter-Korean relations as 'hostile inter-state relations.'[13] Regardless of how much North Korea operates as a single-leader-led system, changes to state strategy require formal procedures. However, North Korea emphasizes that it has no intention of changing its policy. Kim Jong-un stated, 'We have no reason to sit down with South Korea and will do nothing with them,' and 'We will make it clear that we will not associate with them in any way.' Furthermore, he argued directed at the South Korean government, 'Regardless of whether they profess to be "democratic" or wear the guise of "conservative," South Korea's inherent ambition to collapse our system and regime has never changed and can never change, and we are clearly showing them that an enemy is an enemy.' A speech with precisely the same wording was delivered at the Supreme People's Assembly in January 2024,[14]and Kim Yo-jong also issued a similar statement.[15] This indicates a stance of 'no association,' irrespective of the nature of the South Korean government.

However, North Korea implies that it could establish relations as individual states if South Korea takes the following measures. First, it demands the cessation of all types of joint military exercises. Since the inauguration of the Trump administration, it has consistently criticized and condemned all exercises involving South Korea and the U.S. Kim Jong-un's and Kim Yo-jong's speeches and statements also convey the message that joint military exercises are 'war frenzies' and should ultimately be permanently halted.[16]

Second, it demands that South Korea amend its constitution to remove hostile clauses towards North Korea. Kim Jong-un's speech recalled the era of President Syngman Rhee and criticized that 'by inscribing the phrase "The territory of the Republic of Korea shall be the Korean Peninsula and its adjacent islands" in the first Constitution of the Republic of Korea, fabricated and promulgated in July 1948, they codified the inherent nature of being most hostile towards our state.'[17] Although North Korea states it will include similar provisions in its constitution, the status of the North Korean constitution is incomparably lower than that of the South Korean constitution, thus it can be interpreted as a demand for South Korea to ultimately amend its constitution and accept North Korea's 'hostile inter-state theory.' For reference, the North Korean constitution is subordinate to the Party rules, which in turn are subordinate to the leader's directives.

Finally, it demands the withdrawal of U.S. Forces Korea and the dissolution of the alliance. Kim Jong-un stated, 'Reunification is absolutely unnecessary,' and characterized South Korea as a 'country that has entrusted its politics and defense to foreign powers.'[18] This is a message implying that if South Korea desires a deep relationship with North Korea, including discussions on reunification, it must sever ties with the U.S. North Korea also knows that it is impossible for South Korea to accept all three conditions, and therefore, this can be interpreted as a pretext to completely exclude South Korea.

The immediate priority for the South Korean government is to finalize and clearly explain its principles. Since it has only been four months since its inauguration, it may take more time to formalize its core policies. In that case, rather than revealing principles and concepts piecemeal, it should promptly develop and explain an integrated policy on North Korea, unification, and denuclearization to the public and announce it externally to prevent confusion.

Above all, cooperation with the United States is crucial. Although the Trump administration has been in office for eight months, it has not yet announced its official North Korea policy. Despite the existential threat posed by the North Korean nuclear issue to South Korea, since the U.S. is the primary actor in denuclearization negotiations, South Korea must urgently consult closely with the U.S. to align its policies on North Korea and denuclearization. If the U.S. disagrees with the 3-stage approach advocated by South Korea, South Korea's credibility will diminish. Given North Korea's complete exclusion of South Korea, it is imperative for South Korea to reflect its positions through the U.S. and create space for improving inter-Korean relations. This makes the South Korea-U.S. relationship even more important.

Specifically, the ambiguous terminology of the 3-stage denuclearization theory, which has been used interchangeably, needs to be redefined in terms of verifiability, binding force, and linkage to compensation to minimize errors in policy translation. The asymmetry in threat perception between 'U.S. homeland-centric deterrence' and 'threats facing South Korea' must be exposed, and practical guidelines for extended deterrence that bridge this gap, such as clarifying redlines, maintaining visible joint military posture, and establishing swift consultation procedures in times of crisis, should be further developed. Even with North Korea's firm stance of non-cooperation, negotiations should be presented as a means and deterrence as the goal, with 'freeze and verify' as the initial stage standard, thereby enhancing the consistency of South Korea-U.S. cooperation frameworks and messages to North Korea.

In conclusion, this paper has demonstrated that while the South Korean government's '3-stage denuclearization theory' and 'END proposal' possess a declarative structure, they require structural improvements in conceptual clarity ( 'freeze & verify' versus 'interruption'), focus of threat perception (threats facing South Korea versus U.S. homeland-centric), and implementation mechanisms (institutionalization and visualization of extended deterrence). As North Korea defines inter-Korean relations as 'hostile inter-state relations' and undermines the premise of negotiation, signs of operationalization of tactical systems on the Ukraine battlefield and threats from short- and medium-range missiles like the KN-23 directly impact South Korea's security. Therefore, South Korea must standardize its policy lexicon to 'freeze & verify,' and further institutionalize operational guidelines for extended deterrence between South Korea and the U.S., including documentation of redlines, constant visualization of joint forces, and swift consultation procedures during crises. Messages to North Korea should be based on the principle that negotiation is a means and deterrence is the goal, with the phased design restructured, and compensation should be strictly limited to cases linked with verification and safeguards against regression. Only when conceptual consistency and alliance effectiveness are combined can the rhetoric of 'END' be transformed into a strategy that actually reduces risk. ■

[1] El presente artículo amplía y profundiza el texto del autor “Más allá del banquete de palabras, la realidad de las armas nucleares de Corea del Norte y la seguridad de Corea” (Chosun Ilbo Perspective, 20 de septiembre de 2025).

[2] Gobierno de la República de Corea, comunicado de prensa “El Presidente Lee enfatiza los esfuerzos para resolver el ‘riesgo geopolítico’ durante su visita a la Bolsa de Nueva York”, 25 de septiembre de 2025.

[3] Executive Order 14186, “The Iron Dome for America,” Federal Register 90 FR 8767 (3 de febrero de 2025), firmado el 27 de enero de 2025.

[4] Solicitud de audiencia de nombramiento del Presidente del Estado Mayor Conjunto (Jin Young-seung) (Presidente), Sistema de Información de Asuntos Legislativos de la Asamblea Nacional (material presentado ante el Comité de Defensa Nacional).

[5] Congressional Research Service, "North Korea's Nuclear Weapons and Missile Programs," 23 de mayo de 2025, https://www.congress.gov/crs_external_products/IF/PDF/IF10472/IF10472.39.pdf

[6] Oficina Presidencial de la República de Corea, “Entrevista del Presidente Lee Jae-myung con Yomiuri Shimbun”, 19 de agosto de 2025.

[7] Time Magazine, "President Lee Jae-Myung's Plan to Reboot South Korea," 17 de septiembre de 2025, https://time.com/7317953/south-korea-president-lee-jae-myung-cover/

[8] Korea Times, "S. Korean President Lee Jae Myung's UN General Assembly Address," 23 de septiembre de 2025, https://www.koreatimes.co.kr/foreignaffairs/20250924/full-text-s-korean-president-lee-jae-myungs-un-general-assembly-address.

[9] Pavel Podvig, "Freeze and Verify: Ending Fissile Material Production on the Korean Peninsula," United Nations Institute for Disarmament Research (UNIDIR), Ginebra, Suiza, 2020, p. 9, https://unidir.org/wp-content/uploads/2023/05/FreezeandVerify.pdf.

[10] El texto original en inglés es el siguiente: “As our short-term goal, we should stop their nuclear and missile programs. And we might be able to compensate them for some of these measures and afterwards then pursue disarmament and then complete denuclearization.”

[11] “Celebración de la 13ª sesión del 14º período de sesiones de la Asamblea Suprema del Pueblo de la República Popular Democrática de Corea”, Rodong Sinmun, 22 de septiembre de 2025.

[12] Portavoz del Ministerio de Relaciones Exteriores de Corea del Norte, “Declaración sobre la posición posterior a la reunión de alto nivel RPDC-EE. UU.”, KCNA, 7 de julio de 2018.

[13] KCNA, “Informe sobre la 9ª reunión plenaria del 8º período de sesiones del Partido del Trabajo de Corea”, 30 de diciembre de 2023.

[14] KCNA, “Informe sobre la 10ª sesión del 14º período de sesiones de la Asamblea Suprema del Pueblo”, 16 de enero de 2024.

[15] Kim Yo-jong, Declaración de la Subdirectora del Comité Central del Partido del Trabajo de Corea, “Las relaciones entre Corea del Sur y Corea del Norte han salido completamente del marco temporal del concepto de compatriotas”, KCNA, 28 de julio de 2025.

[16] “Celebración de la 13ª sesión del 14º período de sesiones de la Asamblea Suprema del Pueblo de la República Popular Democrática de Corea”, Rodong Sinmun, 22 de septiembre de 2025.

[17] “Celebración de la 13ª sesión del 14º período de sesiones de la Asamblea Suprema del Pueblo de la República Popular Democrática de Corea”, Rodong Sinmun, 22 de septiembre de 2025.

[18] “Celebración de la 13ª sesión del 14º período de sesiones de la Asamblea Suprema del Pueblo de la República Popular Democrática de Corea”, Rodong Sinmun, 22 de septiembre de 2025.

■ Park Won-gon_Director del Centro de Estudios Norcoreanos del EAI; Profesor de Estudios Norcoreanos en la Universidad Femenina de Ewha.

■ Responsable y Editor: Lee Sang-jun_Investigador del EAI

    Consultas: 02 2277 1683 (ext. 211) | leesj@eai.or.kr