A Comprehensive Approach towards a Northeast Asian Nuclear Weapon Free Zone: Solving Japan’s Nuclear Trilemma

Tatsujiro Suzuki
Professor, Director, Research Center for Nuclear Weapons Abolition, Nagasaki University (RECNA)


Japan, as the only nation that has suffered a nuclear attack, has been facing a fundamental Nuclear Trilemma: pursuing the goal of nuclear weapons abolition; its dependence on the US nuclear umbrella (“extended nuclear deterrence”); and, its development of a civilian nuclear fuel cycle. Recently, Japan declined to participate in the UN negotiation for a legally binding scheme to prohibit nuclear weapon (“nuclear weapon ban treaty”) while still committing to the ultimate goal of a world without nuclear weapons, citing the gap between nuclear weapon states and non-nuclear weapon states. In fact, given the recent tensions among countries in the Northeast Asia, especially the nuclear threats posed by North Korea, Japan’s dependence on US nuclear umbrella has become stronger. In addition, Japan’s large stockpile of plutonium and complete nuclear fuel cycle capability has generated concerns over its “latent nuclear capability.” To solve Japan’s nuclear trilemma and eliminate international concern, this paper proposes a comprehensive approach towards a Northeast Asian Nuclear Weapon Free Zone published by the Research Center for Nuclear Weapons Abolition, Nagasaki University (RECNA)[i].


Hiroshima and Nagasaki of Japan are the two only cities in the world that have suffered nuclear attacks. Since then, Japan’s anti-nuclear sentiment, based on the tragic and traumatic experiences of bomb survivors (hibakusha), has been the core of Japanese basic non-nuclear policy. Its goal is to eliminate nuclear weapons from the world eventually. On the other hand, despite such strong anti-nuclear weapon sentiment, Japan’s basic security policy has been dependent on the “extended nuclear deterrence” (nuclear umbrella) of the United States of America (USA). Japan’s so-called “Three Non-Nuclear Principles” (not to manufacture, not to possess and not to introduce nuclear weapons) are always coupled with its dependency on the US nuclear umbrella[ii]. In addition, Japan has been promoting civilian nuclear power programs since the US “Atoms for Peace” policy announced in 1954, including a complete nuclear fuel cycle program which is considered as its “latent nuclear capability”. Although the Basic Atomic Energy Act in Japan legally limits Japan’s nuclear energy program to only “peaceful purposes”, it is now understood that its nuclear fuel cycle capability has been developed, at least partially, with the desire to develop such a latent capability[iii],[iv]. In short, Japan’s nuclear and security policies have been facing this nuclear trilemma, (abolition of nuclear weapons and nuclear deterrence plus latent nuclear capability), since the beginning of the nuclear age in Japan.

So, the main challenges of Japan’s nuclear policy are: how to pursue the goal of a nuclear weapon-free world while being dependent on nuclear deterrence; and, how to eliminate concerns over latent nuclear capability while developing a civilian nuclear program. This paper aims to resolve this key trilemma.

Nuclear Weapon Ban Treaty Negotiation and Nuclear Deterrence

On October 27, 2016, the United Nations adopted a resolution to negotiate a legally binding treaty to prohibit nuclear weapons in 2017. This is a historic moment for many nuclear bomb survivors (hibakusha) as well as for many institutions, researchers and NGOs who have been seeking a world free of nuclear weapons. One hundred and twenty-three states voted in favor but 68 states voted against and 16 abstained. Along with the five nuclear weapon states, Japan, one of USA’s allies, benefitting from the “extended nuclear deterrence”, voted against the resolution. It was a difficult decision for Japan, since it is reported that there was an intense pressure from the US Trump administration not to participate in the negotiation[v].

Japan’s position, torn between nuclear abolition and nuclear deterrence, is even clearer now, as shown by the recent statement made by the Japanese government during the UN Conference to negotiate a legally binding instrument to prohibit nuclear weapons in New York in March 2017. Ambassador Takamizawa stated the following and left the Conference;

“Japan has a mission, as the only country which has experienced the devastation of the war-time use of nuclear weapons in Hiroshima and Nagasaki, to raise awareness on the reality of atomic bombings and clear recognition of its humanitarian consequences across borders and generations…Nuclear disarmament and national security are closely linked; it is evident that disarmament will not be feasible without regard for the existing security concerns. Regrettably, given the present circumstances, we must say that it would be difficult for Japan to participate in this Conference in a constructive manner and in good faith.[vi]

Concerns over Japan’s Latent Nuclear Capability

Because of Japan’s basic nuclear policy of recycling plutonium from spent fuel, Japan has already accumulated 47.8 tons of plutonium (10.8 tons in Japan and 37.0 tons in France and the UK where Japan had commercial reprocessing contracts)[vii]. This is the largest stockpile among non-nuclear weapon states and could increase further if the Rokkasho reprocessing plant starts operation and its recycling program into 15–18 reactors, as currently planned, does not move ahead smoothly. If the Rokkasho plant starts operating, Japan’s plutonium stockpile is likely to grow (Takubo and von Hippel 2013).

Most recently, a senior US government official expressed his concern over Japan’s plutonium stockpile and its reprocessing policy. John Wolfsthal, Senior Director for Arms Control and Non-proliferation at the National Security Council said the following in a recent interview with Kyodo Press:

“There is no question that plutonium recycling in Japan has been expensive. That is a challenging future for Japan. If Japan were to change course, they would find the United States to be supportive…. The upcoming renewal in 2018 of a bilateral nuclear agreement with Japan has the potential to become a very controversial issue…If Japan keeps recycling plutonium, what is to stop other countries from thinking the exact same thing?”[viii]

This is exactly the concern expressed by US and other experts in an Open Letter to Prime Minister Abe on March 28, 2016, saying; “We call on Japan to announce….an indefinite postponement of its plan to start the Rokkasho reprocessing plant to further the mutual goal of US and Japan to minimize global stocks of separated plutonium.”[ix]

Concern over reprocessing programs are also spreading in Northeast Asia. The ROK government, during bilateral negotiation with the US, strongly insisted that it has a sovereign right to reprocessing as Japan does. China is now planning to build a commercial reprocessing plant, imported from France, while criticizing Japan for holding a large plutonium stockpile. So, it has become a regional security issue and needs to be addressed with serious attention[x].

North Korea’s Nuclear Policy and Weapon Program: Possibilities for Negotiation

Given the fact that North Korea has now conducted five nuclear tests, in addition to the missile tests conducted in the past, there is a new urgency to examine the North Korean nuclear weapon program with serious attention. In the past, many experts believed that North Korea’s nuclear weapon program was not meant for immediate military purposes, but rather to use nuclear weapon as leverage, to extract concessions from foreign governments (i.e. diplomatic tools for favorable conditions). However, a growing number of experts now suggest that North Korea is seeking a real, functioning nuclear weapon program for genuine military purposes. Jeffrey Lewis recently concluded that “North Korea’s nuclear weapons are not a mere totem or a symbol. They are a real military capability that North Korea believes will deter a US invasion of North Korea”.[xi]

On the other hand, it should be noted that North Korea repeatedly sent the international community signals calling for a negotiation. In January 2015, North Korea proposed that, in exchange for the USA’s temporary suspension of joint military exercises in South Korea, it would be ready to take responsive measures such as suspending nuclear tests. Moreover, on July 6, 2016, North Korea presented five concrete conditions for possible negotiation with the US.[xii] The five points were:

1) all nuclear weapons of the US in South Korea must be publicly disclosed;
2) all nuclear weapons in South Korea should be dismantled and verified;
3) Washington must guarantee that it will not deploy offensive nuclear weapons in South Korea and its vicinity;
4) the US must commit not to use nuclear weapons against North Korea; and,
5) Washington must declare its willingness to withdraw from South Korea all troops holding the authority to use nuclear weapons.

Such conditions are worth considering for all interested parties of the US government. It is now an appropriate time for the US, under new President Donald Trump, to take new initiatives to bring about a possible breakthrough, shifting from its past “strategic patience” policy, which has not worked at all to deter North Korean nuclear weapon programs.

A Comprehensive Approach is needed: A Nuclear Weapon Free Zone in Northeast Asia (NEA- NWFZ)

Now it is clear that engagement with the DPRK cannot be limited to just nuclear and missile issues, but should extend to a more comprehensive agenda including the signing of a peace treaty to end the Korean War, along with the establishment of a Nuclear Weapon Free Zone in Northeast Asia (NEA-NWFZ) which will provide security assurances to a non-nuclear DPRK, the ROK and Japan. Considering the past, and the failed joint statements by North Korea, USA and other countries, Morton Halperin proposes a methodology where a legally binding agreement should be made and then followed by negotiations for details[xiii]. When political leadership is weak, however, it can be difficult and prohibitively time-consuming to go through the parliamentary processes necessary to ratify legal instruments.

Based on such considerations, the “Comprehensive Framework Agreement for the Denuclearization of Northeast Asia” (CFA) has been put forward in RECNA’s Proposal[xiv] as an instrument to be concluded and effectuated with signatures of heads of state of the Six-Party Talks. It would also be possible, in this case, to include specific provisions within the CFA that are requested to be ratified and become strictly legally binding. Appointing an independent non-governmental, authoritative expert group for support and verification of CFA processes could alleviate concerns regarding the CFA being overruled by changing administrations. The expert group will be deeply involved in the process leading up to manifesting the CFA, and work for support and verification to ensure continuity of negotiations after an initial agreement is reached.

Specific Chapters of a “Comprehensive Framework Agreement for the Denuclearization of Northeast Asia” are divided into “Declaratory” or “Actionable” categories and are composed of the following four:

(1) Declare the termination of the Korean War and provide for mutual nonaggression, friendship, and equal sovereignty among CFA state parties. States lacking diplomatic relations will endeavor to succeed in normalizing diplomatic relations. Encourage negotiations among states concerned for the Korean War Peace Treaty. (Declaratory)

(2) Assure equal rights to access all forms of energy, including nuclear energy. Establish a Northeast Asia Energy Cooperation Committee that is dedicated to contributing to the stability of Northeast Asia and the peaceful reunification of the Korean Peninsula. The invitation for committee members should extend beyond the six parties and be open to any state or state groups supporting the cause. Participation of Mongolia and Canada would be welcome. (Declaratory. Actionable details will be decided by the Committee)

(3) Agree on a treaty to establish a Northeast Asia Nuclear Weapon Free Zone. It will include requirements to join the NPT and other details mandated to achieve a NWFZ. Signatory states are obligated to join the Chemical Weapons Convention. The agreement will protect the rights of signatory states for peaceful space exploration in accordance with the 1967 Outer Space Treaty. An article will be provided to place collective sanctions on states in violation of the treaty, while restricting any unilateral sanction imposed by an individual state party because of treaty matters. (Actionable)

(4) Establish a permanent Northeast Asia Security Council. The primary objective of this council will be to ensure the implementation of the CFA. The secondary objective will be, when appropriate, to serve as a platform for discussions involving various Northeast Asian security issues. In the future, the council is expected to deal with more comprehensive security issues. The council could host the verification mechanisms of the NEA-NWFZ. The Six-Parties will form the initial members of the Council, while member states of the Energy Cooperation Committee and any other states offering to cooperate for Northeast Asian security are welcome to be general members. (Actionable)

The proposed “Northeast Asia Nuclear Weapon Free Zone Treaty” includes characteristics unique to the region, as shown below:

(1) State Parties: A six party treaty in a “Three-plus-Three Arrangement” (South Korea, North Korea, and Japan are “Intrazonal States” and the U.S., China, and Russia are “Neighboring Nuclear Weapon States”) would be the most likely to succeed in the current state of affairs. It would be even more desirable for Mongolia, a country with recognized Nuclear Weapon Free Status, to join the NEA-NWFZ as a diplomatic strategy following the 20th anniversary of the declaration of its nuclear weapon free status in 2012.

(2) Flexibility in Effectuating the Treaty: Doubts over achieving a NEA-NWFZ repeatedly point towards the lack of mutual trust between the states within the region. As demonstrated by the Treaty of Tlatelolco, which entered into force after having overcome difficulties between Brazil and Argentina, the system in which articles enter into force can be flexible in order to facilitate achieving a NEA-NWFZ. For instance, the entry-into-force requirements of the NEA-NWFZ treaty can be provided for through their ratification by the three nuclear weapon states (U.S., Russia, China) and two non-nuclear weapon states (Japan and Korea). It may be feasible to provide an option for Japan and Korea to withdraw from the treaty after three to five years, if North Korea continues not to join. By ratifying the treaty under this scheme, Japan and South Korea will enjoy security assurances sooner against the potential threats from nuclear weapon states other than the U.S. As for the benefits to North Korea, an article can be included to provide North Korea with a certain period of time to dismantle its nuclear weapons and facilities, while the U.S. provides immediate security assurances in exchange for North Koreaʼs ratification.

(3) Requirements Prior to Negotiations: Considering that states with nuclear weapons are involved in negotiating a NEA-NWFZ Treaty, there is a need to address the issue of guaranteeing that negotiations are held in good faith once the negotiations commence. For example, North Korea would be requested to commit to a moratorium of nuclear weapon tests and other nuclear weapon related activities. The United States, South Korea, and Japan would likely be requested to commit to a moratorium of joint military exercises around the Korean Peninsula. Such mutually agreed “prior moratoriums” should be adopted before negotiations. The “prior moratoriums” should also explore alleviating current sanctions imposed on North Korea.

(4) Eliminating Dependence on Extended Nuclear Deterrence: When a NWFZ treaty is fully implemented, international law prevents the threat or use of nuclear weapons against the zone. This implies that non-nuclear weapon states within the NWFZ do not need extended nuclear deterrence or a nuclear umbrella. Therefore, a NWFZ is a recommendable mechanism towards cooperative security that does not depend on nuclear weapons. (Because the proposed CFA includes a non-aggression agreement, non-nuclear weapons states in NEA-NWFZ are protected from attacks and threats by conventional weapons, as well as by nuclear weapons. Considering past negotiations for a nuclear weapon-free Korean Peninsula, the possibility of including conventional weapons in the security assurances exists in the context of a NEA-NWFZ.) Nonetheless, there are many concerns and fears over losing the nuclear umbrella. One fear is that states will be defenseless if one state violates the treaty and either attacks or threatens to attack other states. However, once a state violates the treaty, the treaty becomes null and void; the state of affairs will return to pre-treaty conditions, thus they will not be defenseless. To further alleviate anxieties, the treaty could provide that states may take sanctions against the offender in accordance with international law and their individual national constitution

Plutonium Stockpile Reduction and Possible Multilateral Approach

Global stockpiles of separated plutonium are growing steadily mainly due to civilian reprocessing programs in a limited number of countries. In Northeast Asia, DPRK, China and Japan have stockpiles of separated plutonium. Out of these, Japan has the largest stockpile (47.9 ton as of the end of 2015) which has become a source of international concern, especially among the countries in the region.

To reduce international concern and minimize the risks associated with large stockpiles of plutonium, there have been some proposals for possible international schemes. For example, in 2014, Dr. Fred McGoldrick proposed that Japanese stockpile can be put under the IAEA custody[xv]. The UK Government published its policy for its own plutonium disposition, in which they announced their willingness to take titles of foreign owned plutonium stored in the UK[xvi]. International cooperation in plutonium disposition with countries with large plutonium stockpile, such as the US, can also be an option to be considered. The bilateral cooperation agreement between Japan and the US on the peaceful use of nuclear energy, which includes “blanket approval” of reprocessing/plutonium programs in Japan, will expire in June 2018. It would be useful for both Japan and the US to consider possible bilateral cooperation on this issue. Such options can be pursued by Japan, improving confidence in its civilian plutonium programs.

As of today, Japan and China have both enrichment and reprocessing facilities for civilian purposes while DPRK has both facilities for military purposes. In 1992, DPRK and ROK agreed not to possess reprocessing and enrichment facilities under the Joint Declaration, and it may be useful to reconsider such an agreement under the NEA-NWFZ.

Given the fact that there are already running facilities in Japan, China and DPRK, one possible agreement could be to stop further production of plutonium and Highly Enriched Uranium for military purposes, like with the Fissile Material Cutoff Treaty (FMCT). This, combined with a clear commitment to reduce and eliminate existing stockpiles of fissile materials, can minimize the security risks involved in nuclear proliferation.

It is often argued that reprocessing is necessary to deal with spent fuel, and thus it would also be useful to consider possible international schemes for the storage of spent fuel in the region. However, it is quite difficult to select a suitable site for such an international spent fuel storage facility. One possible option is to use existing reprocessing facilities in China or Japan as a possible host for such storage, under the NEA-NWFZ arrangement. It is also worth considering an international storage (or final repository) of radioactive waste as no country in the region has found a site for civilian nuclear waste. Viable options for such waste storage have been proposed including non-governmental approaches, such as “international consortium” and/or “corporate entity” approaches, in which private sectors in interested countries can form business entities to implement waste disposal[xvii].


On July 7, 2017, the Treaty on Prohibition of Nuclear Weapon was adopted by the UN[xviii]. This is a historic moment for nuclear disarmament. Japan must take this opportunity to change its security policy which is currently dependent on the US nuclear umbrella. Japan also needs to fully rethink its commitment to civilian nuclear fuel cycle programs to eliminate international concerns. In order to resolve Japan’s nuclear trilemma, a comprehensive approach towards a Northeast Asian Nuclear Weapon Free Zone (NEA-NWFZ) could be one potential option to pursue. Given the urgent need for Japan to address nuclear threats in the region and to respond to the hibakusha’s voices, it is time for the Japanese government and civil society to work together to transform such a proposal into action.

[i] “Proposal: A Comprehensive Approach toward Northeast Asia Nuclear Weapon Free Zone”, Research Center for Nuclear Weapons Abolition, Nagasaki University (RECNA), March 2015, http://www.recna.nagasaki-u.ac.jp/recna/bd/files/Proposal_E.pdf.

[ii] Now it is proven that the Japanese government had a secret agreement with the US government to allow “bringing in nuclear weapons” to Japanese soil if necessary (without inquiry by the US government). See Ota, Masakatsu, Nichibei ‘Kaku’ Domei: Genbaku, Kaku no Kasa, Fukushima (US-Japan Nuclear Alliance: Atomic Bomb, Nuclear Umbrella, Fukushima), (Iwanami Shinsho, 2014).

[iii] Aikawa, H., Kakuni Miirareta Kokka (Nations obsessed by nuclear ambitions), (Mainichi Press, 2016).

[iv] Fitzpatrick, Mark, Asia’s Latent Nuclear Powers; Japan South Korea, and Taiwan (Routledge, 2016).

[v] “Trump administration opposes Japan’s participation in U.N. talks on banning nukes,” The Japan Times, March 16, 2017, http://www.japantimes.co.jp/news/2017/03/16/national/politics-diplomacy/trump-administration-opposes-japans-participation-u-n-talks-banning-nukes/#.WS5Zp2jyhPY.

[vi] Statement by Ambassador Nobushige Takamizawa, at the “United Nations conference to negotiate a legally binding instrument to prohibit nuclear weapons leading towards their total elimination”, March 27, 2017, New York, http://www.reachingcriticalwill.org/images/documents/Disarmament-fora/nuclear-weapon-ban/statements/27March_Japan.pdf.

[vii] Office of Atomic Energy Policy, Cabinet Office, “The Status Report of Plutonium Management in Japan-2015” (unofficial translation), July 27, 2016, http://www.aec.go.jp/jicst/NC/iinkai/teirei/siryo2016/siryo24/siryo1_e.pdf

[viii] “U.S. would back a rethink of Japan’s plutonium recycling program: White House,” The Japan Times, May 21, 2016, http://www.japantimes.co.jp/news/2016/05/21/national/politics-diplomacy/u-s-back-rethink-japans-plutonium-recycling-program-white-house/#.V1PF1PRAqD_.twitter.

[ix] “Open Letter to Prime Minister Abe; Stop plutonium separation,” Kakujoho, March 28, 2016, http://kakujoho.net/e/call_nuc_scrty.html.

[x] Sakolski, Henry, “Can East Asia avoid a nuclear explosive materials arms race?”, The Bulletin of Atomic Scientists, March 28, 2016, http://thebulletin.org/can-east-asia-avoid-nuclear-explosive-materials-arms-race9295.

[xi] Lewis, Jeffrey, “ Security Challenges and Denuclearization of Northeast Asia,” lecture given at the Public Symposium How to respond to nuclear threats? Peace and Security in Northeast Asia, Nagasaki, November 21, 2016.

[xii] Korea Central News Agency, July 6, 2016.

[xiii] Halperin, Morton H., “A Proposal for a Nuclear Weapons-Free Zone in Northeast Asia”, Global Asia, Vol. 6, №4 (Winter 2011). Originally presented at ‘East Asia Nuclear Security Workshop’, November 11, 2011, Tokyo, cosponsored by Nautilus Institute, Mansfield Foundation, and Asia-Pacific Leadership Network for Nuclear Non-proliferation and Disarmament (APLN).

[xiv] “Proposal: A Comprehensive Approach toward Northeast Asia Nuclear Weapon Free Zone”, Research Center for Nuclear Weapons Abolition, Nagasaki University (RECNA), March 2015, http://www.recna.nagasaki-u.ac.jp/recna/bd/files/Proposal_E.pdf.

[xv] McGoldrick, Fred, “IAEA Custody of Japanese Plutonium Stocks; Strengthening Confidence and Transparency”, Arms Control Today, September 28, 2014, https://www.armscontrol.org/print/6555.

[xvi] “Management of the UK’s Plutonium Stocks”, UK Department of Energy and Climate Change, February 2011, https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/42766/1243-uk-plutonium-stocks.pdf.

[xvii] Sloan, Robert D., “Multinational Storage of Spent Nuclear Fuel and Other High-level Nuclear Waste: A Roadmap for Moving Forward,” American Academy of Arts and Sciences, 2017, https://www.amacad.org/multimedia/pdfs/publications/researchpapersmonographs/GNF-Spent-Nuclear-Fuel/GNF_Spent-Nuclear-Fuel-Storage.pdf.

[xviii] United Nations General Assembly, Draft treaty on the prohibition of nuclear weapons, A/CONF.229/2017/L.3/Rev.1 (July 6, 2017), http://www.undocs.org/en/a/conf.229/2017/L.3/Rev.1.

Suzuki Tatsujiro, Director and Professor Research Center for Nuclear Weapons Abolition (RECNA) at Nagasaki University

Born in 1951. Before joining RECNA, he was a Vice Chairman of the Japan Atomic Energy Commission (JAEC) of the Cabinet office (2010–2014). He is also a Council Member of Pugwash Conferences on Science and World Affairs (2007–09 and from 2014~), and is the Chair of Pugwash Japan. Previously, he was an Associate Vice President of the Central Research Institute of Electric Power Industry in Japan (1996–2009) and Visiting Professor at the Graduate School of Public Policy, University of Tokyo (2005–009), an Associate Director of MIT’s International Program on Enhanced Nuclear Power Safety from 1988–1993 and a Research Associate at MIT’s Center for International Studies (1993–95). Dr. Suzuki has a PhD in nuclear engineering from Tokyo University (1988).