Indian Council of World Affairs

Abstract: Japan and South Korea, as nuclear latent countries, possess an advanced and dynamic civil nuclear programme that raise questions about their nuclear capabilities. The paper attempts to examine the scope and sophistication of their civil nuclear capabilities and its potential. This study further looks at the American extended deterrence in shaping South Korea and Japan’s strategic decisions and its broader implications for region’s security. 

Introduction

The treaty on the Non-Proliferation of nuclear weapons (NPT) defines a nuclear weapon state as “one which has manufactured and exploded a nuclear weapon or other nuclear explosive device prior to 1 January 1967”.[i] In this context, the United States, Russia, China, France and the United Kingdom are considered nuclear states under the NPT. India, Pakistan and Israel are additional countries, which are not signatories to the NPT but possess and have tested nuclear weapons and are considered nuclear states. North Korea’s (DPRK) constitution, which was amended in 2013, describes itself as a “nuclear state and an unchallengeable military power.”[ii] Others with no such possessions of nuclear weapons are dubbed as non-nuclear states. However, there is a third category that falls outside the purview of the first two, which is known as nuclear latency.

Latent time can be an indication of a states’ use of its resources with the motivations and intent to procure a nuclear weapon.[iii] Latency, thus, includes those states that, possess the technology, capability and intellect to develop nuclear weapons, yet do not do so, remaining latent or non-nuclear. Japan and South Korea (referred to as the Republic of Korea or ROK) fall under this category.

Tokyo and Seoul, despite having a robust and dynamic nuclear energy programme, remain wary of nuclear weapons. They remain steadfast in their commitment to the NPT agreement and establishing a nuclear weapons-free zone in Asia, particularly Northeast Asia, with South Korea signing the Non-Proliferation Treaty (1968) in 1968 and ratifying it in 1975[iv], while Japan signed it in 1970 and ratified it in 1976[v].

Nuclear proliferation has become one of the biggest security challenges of the modern world. The nuclear threat posed by the nuclearisation of DPRK after its exit from the NPT in 2003[vi] has been the biggest challenge to the non-proliferation regimes of Japan and the ROK. The test firing of a medium-range missile over the Japanese mainland in 1998 by DPRK alarmed Japan. It realised that the missile’s apparent range could target any part of Japan and the Republic of Korea by default.[vii]

The extended deterrence provided by the United States helps to somewhat restore the security balance in the region; however, questions are being raised about the sufficiency of the US nuclear umbrella. This paper attempts to examine the potential consequences of the same by analysing the nuclear capabilities of Tokyo and Seoul and the role that American deterrence plays in regard to the security dilemma in the region.

Debates on Shifting Dynamics from Latency to Weaponisation

The shifting power dynamics on the world stage have made Japan and the ROK more susceptible to making increased proliferation choices, especially due to a growing mistrust regarding the credibility of the US extended nuclear deterrent among some conservative Japanese security officials and analysts.[viii]

Korean experts have questioned whether Washington would be willing to sacrifice New York for Tokyo or Seoul[ix] should a situation arise where extended deterrence might be required. This scenario is even more significant, especially now due to the change in governments and the revamped protectionist policy under the new American President, Donald Trump. Today, the US-Japan and US-ROK alliances are experiencing what can be dubbed as “Trump Shocks”.[x]

This scepticism is further enhanced due to the demands of President Trump to Tokyo and Seoul to pay more after two weeks of reaching a troop-funding deal under the Biden administration in 2024 (in which Seoul already agreed to increase the funding to 8.3% by 2026, paying $1.13 billion). Moreover, Trump’s alluding to having good relations with the North Korean leader Kim Jong Un,[xi] before being elected, led to concerns being raised in ROK regarding the US’ alliances and commitment to protecting the Korean peninsula.

Yet, Trump’s re-election is seen as a renewed opportunity for Seoul, with Cheong Seong-chang, a South Korean political analyst, writing that “The re-election of Trump is an opportunity for South Korea to create its nuclear weapons”[xii] in addition to the chair of the Korean ruling People Power Party, Han Dong-Hoon, claiming that there were upsides to Trump’s victory in a discussion regarding the future of South Korea’s nuclear weapons policy.[xiii]

Moreover, an increasing number of South Koreans believe that the country should develop nuclear weapons. According to a recent survey by the state-affiliated Korea Institute for National Unification think tank, 66% of respondents expressed “support” or “strong support” for an independent nuclear deterrent. In a survey conducted by Gallup Korea in February 2024, 72.8% of respondents believed that South Korea should develop its nuclear weapons. Thus, 60%–70% of South Koreans were in favour of their country developing nuclear weapons.[xiv]

The idea for Seoul and Tokyo to develop their own nuclear arsenal is especially advantageous in the case of ROK, whose immediate neighbour, DPRK has already conducted successful nuclear tests and the DPRK’s exit from the NPT agreement, gives rise to regional instability.

Furthermore, Pyongyang has released the inside images of two of its gas centrifuge enrichment plants, demonstrating uranium enrichment capability, though it seems insufficient for weapons production.[xv] Although the reality of a third plant remains a mystery as the state does not follow the IAEA protocols of transparency set in place, adding another layer of scepticism and fears about the nuclear capabilities of DPRK feeding into the security dilemma. The lack of transparency is also true in the case of China, whose expansionist policy and refusal to give reasons or explanations for its accelerated nuclear arms possession make it a hostile adversary presenting a new-age security challenge.

In lieu of these current developments and the lack of faith in American deterrence, it was not surprising that the newly elected Japanese Prime Minister, Shigeru Ishiba, floated the idea of creating an Asian NATO with the possibility of nuclear weapon sharing with the US and the introduction of nuclear weapons into the region to establish deterrence against the nuclear capabilities of China, Russia and DPRK[xvi]. Japan, which produces low-enriched uranium (LEU) at Rokkasho for Japan’s extensive nuclear power programme, could easily produce HEU (highly enriched uranium) used for Weapons of Mass Destruction (WMDs). Even today, a Japanese research reactor (UTR KINKI) and two critical assemblies (KUCA) are still HEU-powered by the US and the UK. [xvii]

Uranium enrichment poses a nuclear proliferation risk because the same technology that can produce LEU for reactor fuel can also be used to produce HEU for nuclear weapons[xviii]. This gave rise to China’s assertion that Japan has a “bomb in the basement”,[xix] prompting a regional security dilemma.

Nuclear Capabilities

Regional assertions about Japan and ROK developing nuclear weapons in spite of being nuclear latent countries stem from their ambitious and strong nuclear programmes. However, both Seoul and Tokyo have embraced the peaceful use of nuclear technology to provide a substantial portion of their electricity needs.

ROK is strongly committed to nuclear power development as an integral part of its national energy policy in line with its industrialisation policy and is fuelled by energy security considerations. Its policy towards the development and usage of atomic energy is driven by the desire to minimise external vulnerability by insuring against global fossil fuel shortages[xx] decreasing dependency on imported fuels[xxi] and reducing greenhouse gas emissions.

ROK has 27 nuclear reactors with a generating capacity of 31.65 GWh, with atomic energy accounting for approximately 29.6% of its electricity generation in 2024[xxii] as compared to 26% in 2020,[xxiii] implying an increased trend toward nuclear energy patterns.

This comes in light of the revised nuclear energy policy since Japan’s Fukushima Daiichi nuclear accident (2011), wherein the Moon Jae-in government of ROK announced an atomic energy phase-out policy over a period of about 40 years, which will cut the number of operating nuclear reactors to 14 units by 2038.[xxiv] However, some stakeholders in South Korea’s power industry have expressed concerns about the feasibility of decommissioning 42% of the commercial nuclear fleet,[xxv] especially since the energy policy continues to have nuclear power as a major element of electricity production, with the ROK ranking as the fifth-largest nuclear power producer in the world.[xxvi]

Japan, while also equally embracing the peaceful use of nuclear technology to provide a substantial portion of its electricity, is the only state without nuclear weapons to have nuclear fuel cycle technology. [xxvii]

Due to the scarcity of resources, including any indigenous sources of uranium, the Japanese Federation of Electric Power Companies (FEPC) claimed that it is essential to organise a nuclear fuel cycle in Japan in order to secure stable energy in the future. Japan’s annual requirements are normally met from Australia, Canada, Kazakhstan and elsewhere. Most enrichment services in Japan are imported, with the exception being the commercial enrichment plant at Rokkasho – RE2A operated by Japan Nuclear Fuel Ltd (JNFL).[xxviii]

Aiming for early and maximum implementation of Pluthermal [MOX] fuel use with 12 nuclear units using MOX by 2030, the FEPC claims that MOX remains vital; however, as of 2025, only four of Japan’s operating nuclear units use MOX[xxix], thereby leading to more stored and enriched plutonium in Japan, capable of being enriched further to make WMDs. Additionally, according to the latest Status Report of Plutonium Management in Japan released at the end of 2020 by the government of Japan, the total amount of separated plutonium within and outside of Japan was approximately 46.1 tonnes, of which approximately 8.9 tonnes was held domestically.[xxx]

This presents a challenge, as the Japan Atomic Energy Commission (JAEC) has declared the policy to reduce the amount of Japan’s plutonium stockpile according to “The Basic Principles on Japan’s Utilization of Plutonium” published in July 2018[xxxi]. This was done in regard to the use of nuclear energy and with the motive of enhancing transparency concerning its peaceful use, as stated by JAEC in February 2024.[xxxii]

Japan operates with a fleet of 33 nuclear power reactors, but 10 of those remain operational following the new regulatory requirements established in 2013 by the Nuclear Regulation Authority (NRA). [xxxiii] In 2011, nuclear energy accounted for almost 30% of Japan’s total electricity production. However, due to safety concerns and an enhanced populist anti-nuclear sentiment following the Fukushima disaster, Japan’s nuclear energy production decreased from 47.5 GWe of net capacity in March 2011 to 44.6 GWe of net capacity since. [xxxiv]

The Japanese government’s stated aim for nuclear power was to provide 20-22% of electricity by 2030; however, there were plans to increase this to 41% by 2017 and 50% by 2030[xxxv], but these fell through as Japan sought to balance populist sentiment with the need for reliable and affordable electricity supplies. Japan and the ROK have introduced a gradual phase-out plan to reduce dependency on nuclear energy as the public sentiment shifted markedly, followed by widespread public protests in support of abandoning nuclear power after the 2011 Fukushima Daiichi accident.

There is a renewed scepticism against the usage of nuclear power, and they remain committed to latency; nevertheless, their enthusiastic nuclear programme, despite public opposition, remains an integral part of these nations’ economies, highlighting their capability in handling materials involved in the nuclear fuel cycle. Japan and South Korea have also become embroiled in this controversy due to the extended deterrence provided by the US and their robust cooperation with Washington in the civil nuclear programmes, signing 123 agreements with the US[xxxvi] (with the Japanese agreement [xxxvii] being in place until terminated by either party and the Korean agreement [xxxviii] in force until 2040).

US Nuclear Umbrella

The 123 agreements even with its civilian nature are crucial since proliferation today seemed inevitable seeing as the contemporary era has been dubbed a “nuclear world”, by President Donald Trump.[xxxix] There is a greater security risk in the Asia-Pacific due to the realities of the present — a nuclear DPRK with an advanced missile and nuclear programme and its increasing cooperation with Russia, the Russia-Ukraine conflict with renewed nuclear rhetoric in place and the Chinese expansionist policy with a growing nuclear stockpile. Therefore, in such a scenario, the extended deterrence provided by the US to Japan and South Korea becomes vital.

Washington’s allies and partners, therefore, want reassurance that Washington’s nuclear umbrella remains in place as the current scenario becomes increasingly hostile and aggressive with enhanced security threats to use nuclear weapons. Deputy Secretary of the US, Kurt Campbell, assured that “the nuclear umbrella extends clearly as in the past”, stating that the commitment to deterrence is central to maintaining peace and security. Campbell has also termed the Japanese-US alliance as “our most important bilateral” relationship.[xl] Additionally, at a joint press conference in 2024 with Japanese Prime Minister Fumio Kishida, President Joe Biden called the 70-year-old alliance between the two nations “a beacon to the entire world” of working together on issues and shared concerns.[xli]

Japan and the US also established the Extended Deterrence Dialogue (EDD) in 2010, which is an important platform to discuss ways to sustain and strengthen extended deterrence. At the 2024 meeting of the EDD, the two sides emphasised the importance of strengthening cooperation to defend against potential attacks, deter nuclear use[xlii] and ensure that extended deterrence is strong and credible.[xliii]

The 1960 Japan-US security alliance is the backbone of deterrence in the region, with the US having approximately 55,000 US military personnel stationed in Japan and thousands of civilians and family members of the Department of Defence who live and work there. The US has also deployed advanced military assets to Japan, including the USS Ronald Reagan carrier strike group and the F-35 Joint Strike Fighter. Since 1997, US Forces and the Japanese Self-Defence Forces jointly conducted Exercise Keen Sword, an annual combined field training exercise designed to increase combat readiness and interoperability within the framework of the US-Japan Alliance. Furthermore, Japan has actively participated in Exercise Malabar with the US and India since 2007, becoming its permanent member in 2015.[xliv]

Additionally, South Korea has had a bilateral security alliance with the United States since the Korean War, which includes extended nuclear deterrence and cooperation on missile defence.[xlv] The ROK government has expressed its confidence in the US-extended deterrence commitments and “recognises the importance, necessity and benefit of its enduring reliance on the US nuclear deterrent”. At the 2023 meeting for the seventh anniversary of the Washington Declaration, the two Presidents announced the establishment of a new Nuclear Consultative Group (NCG) to strengthen extended deterrence, discuss nuclear and strategic planning and manage the threat to the non-proliferation regime posed by the Democratic People’s Republic of Korea (DPRK) while also reassuring South Korea on nuclear matters.

However, The ROK faces a dilemma over whether existing capabilities provided by the US are sufficient to deter DPRK’s nuclear threat, while they also fear an aggressive use of nuclear weapons by Washington, which might potentially lead to catastrophic consequences for Seoul. These concerns have been alleviated by the US by ensuring South Korea’s direct participation in decision-making processes and clarifying its role in a nuclear crisis and through an increased visibility of US strategic assets on the Korean Peninsula with at least three US nuclear submarines having made port calls in Busan since the NCG’s inaugural meet.[xlvi]

Furthermore, the US-ROK alliance has established a new bilateral, interagency table-top simulation to strengthen their joint execution and planning, with the ROK providing conventional support to US nuclear operations, as well as participating in the planning for nuclear contingencies. The former US President Joe Biden had reaffirmed the US' commitment to the ROK and the Korean people as “enduring and ironclad” and had proclaimed that the US commitment to extended deterrence to the ROK is backed by the full range of US capabilities, including nuclear.[xlvii] Former President Yoon of South Korea had also affirmed that Seoul will “apply its own capabilities to the Alliance’s combined defence posture”, including working in lockstep with the US to closely connect the capabilities and planning activities of the new ROK Strategic Command and the US-ROK Combined Forces Command.[xlviii].

The United States and the ROK had avowed to cooperate closely to achieve DPRK’s complete, irreversible and verifiable denuclearisation. Besides, they have been committed to bringing DPRK into compliance with its commitments under the 2005 Joint Statement of the Six-Party Talks and its obligations under the relevant UN Security Council resolutions.[xlix] Washington and Seoul continue to enhance and strengthen extended deterrence and have joined forces against threats to their shared security.[l]

Conclusion

Witnessing the devastation firsthand by nuclear weapons, Japan being the only country ever to have been attacked by atomic weapons, the anti-nuclear sentiment runs particularly deep in the country. The end of World War II led to Japan’s constitution for peace coming into force. Japan has a strong aversion to nuclear weapons and remains focused on its use of nuclear technology for peace, with an ambition of creating a Northeast Asian nuclear weapons-free zone.

The ROK has also witnessed the devastating effects of nuclear attacks on Japan (since many Koreans were working under the imperial Japanese government when the attacks took place in 1945), which might have been one of its reasons for abandoning its nuclear weapons programme in the 1970s.[li] ROK has been committed to the pursuit of peaceful nuclear activities since 1957, when it became an IAEA Member State[lii], passing its Atomic Energy Law the following year and establishing the Office of Atomic Energy in 1959.[liii]

However, recently, with a change in the US government and the unprecedented proliferation in countries like North Korea, along with regional security concerns and a lack of complete faith in American deterrence, Japan and South Korea could be forced to consider the nuclear weaponisation option, given the voices emanating domestically, from Japan and ROK’s elite.[liv] Still, the pursuit of nuclear weapons remains controversial and the idea of nuclearisation should be taken with a pinch of salt. The security idea might have wider political implications and will undermine the Japanese stance of non-proliferation and creating a nuclear weapons-free world,[lv] which is also the cornerstone of the US-Japanese alliance and the 123 civil nuclear agreement.[lvi]

While Japan remains comparatively more committed to the principle of not possessing, not permitting, and not producing nuclear weapons[lvii] with a certain consensus amongst Japanese security officials and experts, in contrast, ROK remains a different story. Many South Koreans are perturbed by the political volatility surrounding the 2024 US presidential election, as they are apprehensive about the commitments of a new president who will not feel bound by past agreements.[lviii]

Both Japan and South Korea have the technical and intellectual capabilities to produce nuclear weapons and are nuclear latent countries. Therefore, it is imperative that while anxiety surrounding the nuclear alliance and security threats remain, ROK and Japan should persist in their commitment to using nuclear energy for peaceful purposes in line with the principles set by the IAEA and under the guidelines set by the NPT and NSG and actively pursue their ideals of establishing a nuclear weapons-free zone in Northeast Asia.

*****

*Antra Gupta, Research Intern, Indian Council of World Affairs, New Delhi
Disclaimer: Views expressed are personal.  

End notes

[i] United Nations Office for Disarmament Affairs (UNODA). 2025. “Treaty on the Non-Proliferation of Nuclear Weapons (NPT).” Accessed May 22, 2025. https://treaties.unoda.org/t/npt.

[ii] Arms Control Association. 2025. “Arms Control and Proliferation Profile: North Korea.” Accessed May 22, 2025. https://www.armscontrol.org/factsheets/arms-control-and-proliferation-profile-north-korea.

[iii] Nuclear Security Science and Policy Institute (NSSPI). 2025. “Nuclear Weapons Latency.” Texas A&M University. Accessed May 22, 2025. https://nsspi.tamu.edu/nuclear-weapons-latency-3458/#:~:text=Nuclear%20Weapons%20Latency%20is%20defined,away%20from%20a%20nuclear%20weapon.

[iv] United Nations Regional Centre for Peace and Disarmament in Asia and the Pacific (UNRCPD). 2025. “Republic of Korea.” UNRCPD. Accessed May 22, 2025. https://www.unrcpd.org/region/republic-korea/.

[v] Permanent Mission of Japan to the Conference on Disarmament. 2025. “Japan and the NPT.” Government of Japan. Accessed May 22, 2025. https://www.disarm.emb-japan.go.jp/NPT_info.html.

[vi] Arms Control Association. n.d. “Timeline of the Nuclear Nonproliferation Treaty (NPT).” https://www.armscontrol.org/factsheets/timeline-nuclear-nonproliferation-treaty-npt.

International Peace Institute. 2010. “Japan, the Republic of Korea, and the United States Nuclear Umbrella.” https://www.ipinst.org/wp-content/uploads/2010/04/pdfs_koreachapt2.pdf

[vii] To read more about North Korean nuclearization and missile testing – Ibid- Asia Society. 2025. “A Brief History of Nuclear Weapons States.” Asia Society. Accessed May 23, 2025. https://asiasociety.org/education/brief-history-nuclear-weapons-states.

[viii] Union of Concerned Scientists. 2019. “Japan and the American Nuclear Posture.” https://www.ucs.org/sites/default/files/2019-09/japan-american-nuclear-posture.pdf.

[ix] Kim, Min-seok. 2022. “Would United States Risk New York to Protect Seoul?” Korea JoongAng Daily. June 26, 2022. https://koreajoongangdaily.joins.com/2022/06/26/opinion/columns/extended-nuclear-deterrence-South-Korea-US/20220626200111690.html.

[x] Asia Society Policy Institute. 2020. “Reflections on the U.S.–Japan Security Treaty at 60.” https://asiasociety.org/policy-institute/reflections-us-japan-security-treaty-60.

[xi] Kim, Sohee. 2024. “Trump Says ‘Money Machine’ Korea Should Pay More for U.S. Troops.” Bloomberg. October 16, 2024. https://www.bloomberg.com/news/articles/2024-10-16/trump-says-money-machine-korea-should-pay-more-for-us-troops.

[xii] Kim, Victoria. 2024. “Trump Win Fuels Campaign for Nuclear Arms in South Korea.” Los Angeles Times. November 8, 2024. https://www.latimes.com/world-nation/story/2024-11-08/trump-win-fuels-campaign-for-nuclear-arms-in-south-ko

[xiii] Deutsche Welle (DW). 2024. “Trump’s Comeback Fuels Nuclear Debate in South Korea.” DW. November 8, 2024. https://www.dw.com/en/trumps-comeback-fuels-nuclear-debate-in-south-korea/a-70777884.

[xiv] Geopolitical Monitor. n.d. “The Secret History of South Korea’s Nuclear Weapons Program.” https://www.geopoliticalmonitor.com/the-secret-history-of-south-koreas-nuclear-weapons-program/.

[xv] Albright, David. 2021. “North Korea’s Uranium Enrichment Facilities: What We Learned from KCNA’s Image.” Institute for Science and International Security. April 2021. https://isis-online.org/isis-reports/detail/north-koreas-uranium-enrichment-facilities-what-we-learned-from-kcnas-image/.

Read more on the North Korean threat from the perspective of South Korea- Ministry of Foreign Affairs of the Republic of Korea (MOFA). 2025. “Policy on Peaceful Uses of Nuclear Energy.” MOFA. Accessed May 22, 2025. https://www.mofa.go.kr/eng/wpge/m_5474/contents.do.

[xvi] Asahi Shimbun. 2023. “Japan to Revise Nuclear Policy amid Security Concerns.” https://www.asahi.com/ajw/articles/15450903.

[xvii] Steiger, Dave. 2019. “Civilian HEU: Japan.” James Martin Center for Nonproliferation Studies. July 1, 2019. https://nonproliferation.org/civilian-heu-japan/.

[xviii] Nuclear Threat Initiative (NTI). 2025. “Uranium Enrichment.” NTI Education Tutorials. Accessed May 23, 2025. https://tutorials.nti.org/nuclear-101/uranium-enrichment/.

[xix] Windrem, Robert. 2014. “Japan Has Nuclear 'Bomb in the Basement,' and China Isn't Happy.” NBC News. March 11, 2014. https://www.nbcnews.com/storyline/fukushima-anniversary/japan-has-nuclear-bomb-basement-china-isn-t-happy-n48976.

[xx] IAEA. 2019. “Country Nuclear Power Profiles: Korea, Republic of.” https://www-pub.iaea.org/MTCD/Publications/PDF/cnpp2019/countryprofiles/KoreaRepublicof/KoreaRepublicof.htm.

[xxi] World Nuclear Association. 2025. “South Korea: Nuclear Power Industry.” World Nuclear Association. Accessed May 22, 2025. https://world-nuclear.org/information-library/country-profiles/countries-o-s/south-korea#nuclear-power-industry.

[xxii] International Trade Administration. 2024. “South Korea Nuclear Energy Market Intelligence.” https://www.trade.gov/market-intelligence/south-korea-nuclear-energy.

[xxiii] U.S. Energy Information Administration. 2020. “South Korea Is a Major Nuclear Power Producer.” August 2020. https://www.eia.gov/todayinenergy/detail.php?id=44916.

[xxiv] https://www.reuters.com/article/us-southkorea-nuclear/south-korea-to-resume-building-two-new-nuclear-reactors-but-scraps-plans-for-6-others-idUSKBN1CT0RS/.

[xxv] U.S. Energy Information Administration. 2020. “South Korea Is a Major Nuclear Power Producer.” August 2020. https://www.eia.gov/todayinenergy/detail.php?id=44916.

[xxvi] Nuclear Threat Initiative. n.d. “South Korea.” NTI. Accessed May 2025. https://www.nti.org/countries/south-korea/.

[xxvii] Yoshida, Fumihiro. 2018. “The U.S.–Japan 123 Agreement and the Future of Civil Nuclear Cooperation.” Sasakawa Peace Foundation. March 26, 2018. https://spfusa.org/wp-content/uploads/2018/03/123-Agreement-Yoshida-032618.Final_.pdf.

[xxviii] World Nuclear Association. n.d. “Japan: Nuclear Fuel Cycle and Uranium Supply.” https://world-nuclear.org/information-library/country-profiles/countries-g-n/japan-nuclear-fuel-cycle#uranium-supply.

Read more on JNFL- Japan Nuclear Fuel Limited (JNFL). 2025. “Uranium Enrichment.” JNFL. Accessed May 22, 2025. https://www.jnfl.co.jp/en/business/uran/.

[xxix] Nuclear Engineering International. 2024. “Japan Updates MOX Fuel Plans.” https://www.neimagazine.com/news/japan-updates-mox-fuel-plans/?cf-view&cf-closed.

[xxx] International Panel on Fissile Materials. 2021. “Status of Plutonium Management in Japan.” Fissile Materials. July 20, 2021. https://fissilematerials.org/blog/2021/07/status_of_plutonium_manag_4.html.

[xxxi] Suzuki, Tatsujiro, and Masa Takubo. 2018. “Japan’s New Policy on Its Plutonium Stockpile.” International Panel on Fissile Materials (IPFM) Blog. Accessed May 22, 2025. https://fissilematerials.org/blog/2018/08/japans_new_policy_on_its_.html.

[xxxii] Staff Writer. 2025. “Japan Updates MOX Fuel Plans.” Nuclear Engineering International. Accessed May 22, 2025. https://www.neimagazine.com/news/japan-updates-mox-fuel-plans/.

[xxxiii] World Nuclear Association. n.d. “Japan: Nuclear Power and Electricity Sector.” https://world-nuclear.org/information-library/country-profiles/countries-g-n/japan-nuclear-power#electricity-sector.

[xxxiv] World Nuclear Association. n.d. “Japan: Nuclear Power and Electricity Sector.” https://world-nuclear.org/information-library/country-profiles/countries-g-n/japan-nuclear-power#electricity-sector.

[xxxv] Ibid.- World Nuclear Association. n.d. “Japan: Nuclear Power and Electricity Sector.” https://world-nuclear.org/information-library/country-profiles/countries-g-n/japan-nuclear-power#electricity-sector.

[xxxvi] Read more about 123 Agreements- U.S. Department of State. 2025. “123 Agreements.” U.S. Department of State, Bureau of International Security and Nonproliferation. January 2025. https://www.state.gov/bureau-of-international-security-and-nonproliferation/releases/2025/01/123-agreements.

U.S. Department of Energy, National Nuclear Security Administration. 2025. “123 Agreements for Peaceful Cooperation.” U.S. Department of Energy. Accessed May 26, 2025. https://www.energy.gov/nnsa/123-agreements-peaceful-cooperation.

[xxxvii] U.S. Department of State and Government of Japan. 1988. “Agreement for Cooperation Between the Government of the United States of America and the Government of Japan Concerning Peaceful Uses of Nuclear Energy.” Fissile Materials. November 4, 1988. https://fissilematerials.org/library/jp123.pdf.

[xxxviii] U.S. Department of State. 2025. “U.S.-Republic of Korea (R.O.K.) Agreement for Peaceful Nuclear Cooperation.” U.S. Department of State, Bureau of International Security and Nonproliferation. January 2025. https://www.state.gov/bureau-of-international-security-and-nonproliferation/releases/2025/01/u-s-republic-of-korea-r-o-k-agreement-for-peaceful-nuclear-cooperation.

[xxxix] Trump, Donald. 2016. “Transcript of Interview with Donald Trump.” The New York Times. March 26, 2016. https://www.nytimes.com/2016/03/27/us/politics/donald-trump-transcript.html.

[xl] Hudson Institute. 2024. “A Conversation with Deputy Secretary of State Kurt Campbell: A New Era in the U.S.-Japan Relationship.” Hudson Institute. October 24, 2024. https://www.hudson.org/events/conversation-deputy-secretary-state-kurt-campbell-new-era-us-japan-relationship.

[xli] Eckstein, Megan. 2024. “State Dept. Official: U.S. Committed to Nuclear Defense of Japan, South Korea.” USNI News. April 25, 2024. https://news.usni.org/2024/04/25/state-dept-official-u-s-committed-to-nuclear-defense-of-japan-south-korea.

[xlii] U.S. Department of State. 2024. “U.S.–Japan Extended Deterrence Dialogue.” https://2021-2025.state.gov/u-s-japan-extended-deterrence-dialogue-4/.

Ministry of Foreign Affairs of Japan. 2024. “Japan-U.S. Security Consultative Committee (2+2) Joint Statement.” https://www.mofa.go.jp/press/release/pressite_000001_00374.html.

[xliii] U.S. Department of Defense. 2024. “Government of the United States of America – Government of Japan Guidelines for Extended Deterrence.” April 2024. https://www.defense.gov/News/Releases/Release/Article/4016928/government-of-the-united-states-of-america-government-of-japan-guidelines-for-e/.

[xliv] Ministry of Foreign Affairs of Japan (MOFA). 2025. “Q&A on the Japan-U.S. Security Arrangements.” MOFA. Accessed May 22, 2025. https://www.mofa.go.jp/region/n-america/us/q&a/ref/1.html.

U.S. Department of State. 2024. “U.S. Security Cooperation with Japan.” U.S. Department of State. October 25, 2024. https://www.state.gov/u-s-security-cooperation-with-japan/.

[xlv] Nuclear Threat Initiative. n.d. “South Korea.” NTI. Accessed May 2025. https://www.nti.org/countries/south-korea/.

[xlvi] Kim, James D. 2025. “Upgrading U.S.-ROK Nuclear Deterrence: The Role of the Nuclear Consultative Group.” The National Bureau of Asian Research. March 6, 2025. https://www.nbr.org/publication/upgrading-u-s-rok-nuclear-deterrence-the-role-of-the-nuclear-consultative-group/.

[xlvii] U.S. Embassy & Consulate in the Republic of Korea. 2024. “Joint Statement by President Biden and President Yoon on U.S.-ROK Guidelines for Nuclear Deterrence and Nuclear Operations on the Korean Peninsula.” U.S. Embassy & Consulate in the Republic of Korea. July 12, 2024. https://kr.usembassy.gov/071224-joint-statement-by-president-biden-and-president-yoon-on-u-s-rok-guidelines-for-nuclear-deterrence-and-nuclear-operations-on-the-korean-peninsula/.

[xlviii] Ibid- U.S. Embassy & Consulate in the Republic of Korea. 2024. “Joint Statement by President Biden and President Yoon on U.S.-ROK Guidelines for Nuclear Deterrence and Nuclear Operations on the Korean Peninsula.” U.S. Embassy & Consulate in the Republic of Korea. July 12, 2024. https://kr.usembassy.gov/071224-joint-statement-by-president-biden-and-president-yoon-on-u-s-rok-guidelines-for-nuclear-deterrence-and-nuclear-operations-on-the-korean-peninsula/.

[xlix] U.S. Department of State. 2025. “U.S.-Republic of Korea (R.O.K.) Agreement for Peaceful Nuclear Cooperation.” January 2025. https://www.state.gov/bureau-of-international-security-and-nonproliferation/releases/2025/01/u-s-republic-of-korea-r-o-k-agreement-for-peaceful-nuclear-cooperation.

[l] Ministry of Foreign Affairs, Republic of Korea. 2023. “Washington Declaration.” April 2023. https://www.mofa.go.kr/eng/brd/m_25772/view.do?seq=14&page=1.

[li] Asia Society. 2025. “A Brief History of Nuclear Weapons States.” Asia Society. Accessed May 23, 2025. https://asiasociety.org/education/brief-history-nuclear-weapons-states.

[lii] International Atomic Energy Agency (IAEA). 2024. “Korea, Republic of – Country Fact Sheet.” Office of Legal Affairs. Last updated August 7, 2024. https://ola.iaea.org/Applications/FactSheets/Country/Detail?code=KR.

[liii] International Atomic Energy Agency. 2000. “Nuclear Power Profile: Republic of Korea.” https://www-pub.iaea.org/mtcd/publications/pdf/cnpp2003/cnpp_webpage/PDF/2000/Reports/KOREA.pdf.

[liv] Ibid- Union of Concerned Scientists. 2019. “Japan and the American Nuclear Posture.” https://www.ucs.org/sites/default/files/2019-09/japan-american-nuclear-posture.pdf.

[lv] Ministry of Foreign Affairs of Japan. 2004. “Disarmament and Non-Proliferation Policy.” https://www.mofa.go.jp/policy/un/disarmament/policy/pamph0404/part2.pdf.

[lvi] Read more about the 123 civil nuclear deal between Japan and USA- Yoshida, Fumihiro. 2018. “The U.S.–Japan 123 Agreement and the Future of Civil Nuclear Cooperation.” Sasakawa Peace Foundation. March 26, 2018. https://spfusa.org/wp-content/uploads/2018/03/123-Agreement-Yoshida-032618.Final_.pdf.

[lvii] Read more about Japanese disarmament measures- Ministry of Foreign Affairs of Japan. 2004. “Disarmament and Non-Proliferation Policy.” https://www.mofa.go.jp/policy/un/disarmament/policy/pamph0404/part2.pdf.

Ministry of Foreign Affairs of Japan (MOFA). 2025. “Japan’s Policy on Nuclear Non-Proliferation and Disarmament.” MOFA. Accessed May 22, 2025. https://www.mofa.go.jp/policy/un/disarmament/nnp/.

[lviii] Carnegie Endowment for International Peace. 2024. “Nuclear for Nuclear: Understanding Divergent South Korean and American Perceptions on Deterring North Korea.” June 2024. https://carnegieendowment.org/research/2024/06/nuclear-for-nuclear-understanding-divergent-south-korean-and-american-perceptions-on-deterring-north-korea?lang=en.