Japan

Abstract

Under what conditions would the democracies in Northeast Asia seek to join the nuclear weapons club? Japan, South Korea and Taiwan are threshold nuclear powers by virtue of their robust civilian nuclear-energy programmes. All three once pursued nuclear weapons and all face nuclear-armed adversaries. Fitzpatrick's latest book analyses these past nuclear pursuits and current proliferation drivers. It considers how long it would take each to build a nuclear weapon if such a fateful decision were made but does not predict such a scenario. Unlike when each previously went down a nuclear path, democracy and a free press now prevail as barriers to building bombs in the basement. Reliance on US defence commitments is a better security alternative – as long as such guarantees remain credible. But extended deterrence is not a barrier to proliferation of sensitive nuclear technologies. Nuclear hedging by its Northeast Asian partners will challenge Washington's nuclear diplomacy.

Notes

1 Katsuhisa Furukawa, ‘Japan's Policy and Views on Nuclear Weapon: A Historical Perspective’, Jebat: Malaysian Journal of History, Politics, & Strategic Studies, vol. 37, 2010, pp. 1–2. Claims that Japan developed and tested an atomic bomb in its Korean colony are without merit. See Walter E. Grunden, ‘Hungnam and the Japanese Atomic Bomb: Recent Historiography of a Postwar Myth’, Intelligence and National Security, vol. 13, no. 2, 1998.

2 Masakatsu Ota, ‘U.S. Weighed Giving Japan Nuclear Weapons in 1950s’, Japan Times, 23 January 2015.

3 Richard Samuels and James L. Schoff, ‘Japan's Nuclear Hedge: Beyond “Allergy” and Breakout’, in Ashley J. Tellis, Abraham M. Denark and Travis Tanner (eds), Strategic Asia 2013–14: Asia in the Second Nuclear Age (Washington DC: National Bureau of Asian Research, October 2013), p. 237.

4 Robert S. Norris, William M. Arkin and William Burr, ‘Where They Were’, Bulletin of the Atomic Scientists, vol. 55, no. 6, December 1999, pp. 30–1.

5 US Department of State, ‘Telegram from the Embassy in Japan to the Department of State’, in Foreign Relations of the United States, 1964–68 (Washington DC: US Government Printing Office, 2006), available at https://history.state.gov/historicaldocuments/frus1964-68v29p2/d37.

6 Taka Daitoku, ‘The Construction of a Virtual Nuclear State: Japan's Realistic Approach to an Emerging Nuclear Non-proliferation Regime, 1964–70’, revised version of a paper presented to the Eidgenössische Technische Hochschule Zürich Center for Security Studies workshop ‘Making of a Nuclear Order: Negotiating the Nuclear Non-Proliferation Treaty’, Switzerland, 1 March 2014.

7 Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, pp. 9–10.

8 Yuri Kase, ‘The Costs and Benefits of Japan's Nuclearization: An Insight into the 1968/70 Internal Report’, Non-proliferation Review, Summer 2001.

9 Daitoku, ‘The Construction of a Virtual Nuclear State’.

10 Ibid.

11 Ibid.

12 Michael J. Green and Katsuhisa Furukawa, ‘Japan: New Nuclear Realism’, in Muthiah Alagappa (ed.), The Long Shadow: Nuclear Weapons and Security in 21st Century Asia (Stanford, CA: Stanford University Press, 2008), Chapter 12, pp. 351–2; Nobumasa Akiyama, ‘The Socio-political Roots of Japan's Non-Nuclear Posture’, in Benjamin Self and Jeffrey Thompson (eds), Japan's Nuclear Option: Security, Politics and Policy in the 21st Century (Washington DC: Henry L. Stimson Center, 2003), p. 82.

13 Daitoku, ‘The Construction of a Virtual Nuclear State’.

14 Nobumasa Akiyama, ‘Japan's Disarmament Dilemma: Between the Moral Commitment and the Security Reality’, in George P. Shultz and James Goodby (eds), The War That Must Never Be Fought: Dilemmas of Nuclear Deterrence (Stanford, CA: Hoover Institution Press, 2015), pp. 451–2; Kurt M. Campbell and Tsuyoshi Sunohara, ‘Japan: Thinking the Unthinkable’, in Kurt M. Campbell, Robert J. Einhorn and Mitchell Reiss (eds), The Nuclear Tipping Point: Why States Reconsider Their Nuclear Choices (Washington DC: Brookings Institution Press, 2004), p. 228.

15 Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, p. 20.

16 Green and Furukawa, ‘Japan’, pp. 349, 353.

17 Shamshad A. Khan, ‘Japan's (Un)clear Nuclear Ambition’, Institute for Defence Studies and Analysis, 11 July 2012, http://www.idsa.in/idsacomments/Japansclearnuclearambition_sakhan_110712.

18 ‘Business-as-Usual Alteration of Nuclear Law Unsettling’, Mainichi Shimbun, 2 July 2012, available at http://www.fukushima-is-stillnews.com/article-atomic-energybasic-law-part-4-107697948.html.

19 Llewelyn Hughes, ‘Why Japan Will Not Go Nuclear (Yet)’, International Security, vol. 31, no. 4, Spring 2007, p. 83; Mike M. Mochizuki, ‘Japan Tests the Nuclear Taboo’, Nonproliferation Review, vol. 14, no. 2, July 2007.

20 Akiyama, ‘The Socio-political Roots of Japan's Non-Nuclear Posture’, p. 67.

21 Jonathan Schell, The Seventh Decade: The New Shape of Nuclear Danger (Basingstoke: Palgrave Macmillan, 2007), p. 145.

22 Hans Kristensen, ‘Japan Under the US Nuclear Umbrella’, The Nautilus Institute, 1999, http://oldsite.nautilus.org/archives/library/security/papers/NuclearUmbrella-1.html.

23 Green and Furukawa, ‘Japan’, p. 350.

24 Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, p. 24.

25 Green and Furukawa, ‘Japan’, p. 349.

26 Peter A. Clausen, Non-proliferation and the National Interest (New York: HarperCollins, 1993), pp. 87–9, cited in Motoya Kitamura, ‘Japan's Plutonium Program: A Proliferation Threat?’, Non-proliferation Review, Winter 1996.

27 Etel Solingen, Nuclear Logics: Contrasting Paths in East Asia and the Middle East (Princeton, NJ: Princeton University Press, 2007), p. 58.

28 Akiyama, ‘Japan's Disarmament Dilemma’, p. 437.

29 Maria Rost Rublee, ‘The Threshold States: Japan and Brazil’, Chapter 5 of Tanya Ogilvie-White and David Santoro (eds), Slaying the Nuclear Dragon: Disarmament Dynamics in the Twenty-First Century (Athens, GA: University of Georgia Press, 2012), p. 170.

30 Akiyama, ‘Japan's Disarmament Dilemma’, p. 444.

31 Author's discussions with security experts in Tokyo, November 2014.

32 Examples drawn from Kenneth J. Pyle, Japan Rising: The Resurgence of Japanese Power and Purpose (Cambridge, MA: The Century Foundation, 2007), pp. 366–8.

33 Sang-Moo Hwang, ‘Ilbon Eui Haekmujang Chujinkwah Dongbukah Jungsae’, KBS, 1 July 2012, cited in Samuels and Schoff, ‘Japan's Nuclear Hedge’, p. 256.

34 Etel Solingen, ‘The Perils of Prediction: Japan's Once and Future Nuclear Status’, in William C. Potter (ed.), Forecasting Nuclear Proliferation in the 21st Century: A Comparative Perspective (Stanford, CA: Stanford University Press, 2010), p. 155.

35 Author interview in Tokyo, November 2014.

36 Donald S. Zagoria, ‘NCAFP Factfinding Mission to Seoul, Taipei, Beijing and Tokyo 18 October–2 November, 2014’, National Committee on American Foreign Policy, https://www.ncafp.org/ncafp/wp-content/uploads/2014/12/NCAFP-Asia-Trip-Report_November-2014.pdf.

37 Jacques E.C. Hymans, ‘Veto Players, Nuclear Energy, and Non-proliferation: Domestic Institutional Barriers to a Japanese Bomb’, International Security, vol. 36, no. 2, October 2011, p. 188. Llewelyn Hughes also argues that Japan has not implemented hedging as a ‘coherent national strategy’. See Hughes, ‘Why Japan Will Not Go Nuclear (Yet)’, p. 69.

38 Takuya Kubo, ‘Boueiryoku Seibi no Kangaekata’, 20 February 1971, http://www.ioc.u-tokyo.ac.jp/~worldjpn/documents/texts/JPSC/19710220.O1J.html, cited in Hajime Izumi and Katsuhisa Furukawa, ‘Not Going Nuclear: Japan's Response to North Korea's Nuclear Test’, Arms Control Today, June 2007.

39 Quoted in Daitoku, ‘The Construction of a Virtual Nuclear State’.

40 Quoted in Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, p. 8.

41 Andrew L. Oros, ‘Godzilla's Return: The New Nuclear Politics in an Insecure Japan’, in Benjamin L. Self and Jeffrey W. Thompson (eds), Japan's Nuclear Option: Security, Politics, and Policy in the 21st Century (Washington DC: Henry L. Stimson Center, 2003), p. 51.

42 Sam Jameson, ‘Official Says Japan Will Need Nuclear Arms if N. Korea Threatens’, Los Angeles Times, 29 July 1993.

43 David Sanger, ‘In Face-Saving Turn, Japan Denies Nuclear Know-How’, New York Times, 22 June 1994.

44 Morihiro Hosokawa, ‘Are U.S. Troops in Japan Needed? Reforming the Alliance’, Foreign Affairs, vol. 77, no. 4, July–August 1998, p. 5.

45 Ariel Levite, ‘Never Say Never Again: Nuclear Reversal Revisited’, International Security, vol. 27, no. 3, Winter 2002–03, p. 71.

46 ‘Japanese Official Quits After Backing Nuclear Armaments’, Chicago Tribune, 21 October 1999.

47 ‘Tokyo Politician Warns Beijing It Can Go Nuclear “Overnight”’, Agence France-Presse, 8 April 2002.

48 Howard W. French, ‘Koizumi Aide Hints at Change to No Nuclear Policy’, New York Times, 4 June 2002, p. 10.

49 ‘Koizumi Denies Change in Non-Nuclear Policy amid Reports of Officials Suggesting a Switch’, Associated Press, 31 May 2002, cited in Eric Talmadge, ‘Controversy over Remarks on Japan Nuclear Option’, Disarmament Diplomacy, no. 65, July–August 2002, http://www.acronym.org.uk/dd/dd65/65nr07.htm.

50 Campbell and Sunohara, ‘Japan’, p. 230.

51 Cited in Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, p. 15.

52 Chester Dawson, ‘In Japan, Provocative Case for Staying Nuclear’, Wall Street Journal, 28 October 2011; interview with Masakatsu Ota, Shinano Mainichi Shimbun, 25 October 2011, translated in ‘Nautilus Peace and Security – 13 November’, NAPSNet Weekly Report, 12 November 2014, http://nautilus.org/napsnet/napsnet-weekly/nautilus-peaceand-security-13-november/.

53 ‘Musekininna Syusho no Seissaku Minaoshiron’, Yomiuri Shimbun, 10 August 2011; ‘Tenbo Naki “datsu genpatsu” to ketsubetsu wo’, Kyodo, 7 September 2011, cited in Masakatsu Ota, ‘The Fukushima Nuclear Crisis and Its Political and Social Implications’, in Bong Youngshik and T.J. Pempel (eds), Japan in Crisis: What Will It Take for Japan to Rise Again? (Seoul: Asan Institute for Policy Studies, 2013).

54 ‘Japan Defense Chief Morimoto Sees Nuclear Plants as Deterrent, Favors 25% Option for Energy Mix’, Kyodo, 12 September 2012, available at http://www.acronym.org.uk/news/201209/japan-defensechief-morimoto-sees-nuclearplants-deterrent-favors-25-optionenergy-mix.

55 Robert Windrem, ‘Japan Has Nuclear “Bomb in the Basement”, and China Isn't Happy’, NBC, 11 March 2014, http://www.nbcnews.com/storyline/fukushima-anniversary/japan-has-nuclearbomb-basement-china-isnthappy-n48976.

56 Interview, January 2015.

57 Interview with a journalist in Tokyo, November 2014.

58 Some authors claim Japan has developed electronic triggers and other parts necessary for nuclear bombs. The source for these claims is a 1994 article in the Sunday Times, citing a purported UK Ministry of Defence report to the Joint Intelligence Committee (Nick Rufford, ‘Japan to “Go Nuclear” in Asian Arms Race’, Sunday Times, 30 January 1994). The newspaper has a reputation for sensationalism and does not require double sourcing for its exposés.

59 See James M. Acton, ‘Wagging the Plutonium Dog: Japanese Domestic Politics and Its International Security Implications’, Carnegie Endowment for International Peace, 29 September 2015, http://carnegieendowment.org/files/Plutonium_Dog_final.pdf.

60 Hughes, ‘Why Japan Will Not Go Nuclear (Yet)’, pp. 80–1.

61 Kitamura, ‘Japan's Plutonium Program’.

62 US Energy Information Administration, ‘Japan: International Energy Data and Analysis’, 30 January 2015, http://www.eia.gov/beta/international/analysis.cfm?iso=JPN.

63 The Japan Atomic Energy Commission established this goal in 1956 in the first Long-Term Program for the Research, Development, and Utilization of Nuclear Energy.

64 Jeffrey W. Thompson and Benjamin L. Self, ‘Nuclear Energy, Space Launch Vehicles, and Advanced Technology: Japan's Prospects for Nuclear Breakout’, in Benjamin L. Self and Jeffrey W. Thompson (eds), Japan's Nuclear Option: Security, Politics, and Policy in the 21st Century, (Washington DC: Henry L. Stimson Center, 2003), p. 151.

65 Government of Japan, ‘Strategic Energy Plan’, April 2014, p. 54, http://www.enecho.meti.go.jp/en/category/others/basic_plan/pdf/4th_strategic_energy_plan.pdf.

66 Japan calls the MOX use ‘pluthermal’ (plusamuru), a Japanese combination of plutonium and thermal reactors (in contrast to fast-breeder reactors).

67 Acton, ‘Wagging the Plutonium Dog’.

68 Kitamura, ‘Japan's Plutonium Program’.

69 Douglas Birch, R. Jeffrey Smith and Jake Adelstein, ‘Plutonium Fever Blossoms in Japan’, The Center for Public Integrity, 19 May 2014, http://www.publicintegrity.org/2014/03/12/14394/plutonium-fever-blossoms-japan.

70 Victor Gilinsky, Marvin Miller and Harmon Hubbard, ‘A Fresh Examination of the Proliferation Dangers of Light Water Reactors’, Non-proliferation Education Center, 22 October 2004, http://npolicy.org/article.php?aid=172#_ftn_Main_22.

71 Communications with former US State Department official Fred McGoldrick, who was involved in US–Japan nuclear diplomacy at the time.

72 Ibid. A similar policy determination was made for India in 2010 by president George W. Bush.

73 White House, ‘Fact Sheet — Non-proliferation and Export Control Policy’, 27 September 1993, available at http://fas.org/spp/starwars/offdocs/w930927.htm.

74 Toshihiro Okuyama, ‘U.S. Alarmed about Plutonium Stockpile Growing from Rokkasho Plant’, Asahi Shimbun, 13 April 2014, http://ajw.asahi.com/article/behind_news/politics/AJ201404130029.

75 ‘Uranium for 20 Nukes Repatriated from Japan in Special U.S. Operation’, Kyodo, 27 December 2008.

76 Interview in Tokyo, November 2014.

77 Rublee, ‘The Threshold States’, p. 163.

78 Emma Chanlett-Avery and Mary Beth Nikitin, ‘Japan's Nuclear Future: Policy Debate, Prospects, and U.S. Interests’, Congressional Research Service, 19 February 2009, pp. 5–6, available at http://assets.opencrs.com/rpts/RL34487_20080509.pdf.

79 ‘Japan's Nuclear Fuel Cycle Futures: Evaluating the Non-proliferation Impact of Japan's Nuclear Fuel Cycle Decisions’, summary of a workshop co-hosted by the Center for Strategic and International Studies Proliferation Prevention Program and Hitotsubashi University, 20 November 2014, http://csis.org/files/publication/141120_Report_Japan_Nuclear_Fuel_Cycle_Futures.pdf.

80 The 47.8-tonne figure is the amount of total plutonium. The amount of fissionable plutonium (Pu-239 and Pu-241) is approximately 30 tonnes, 6.3 tonnes of which is stored in Japan. Since 1994, Japan has voluntarily disclosed data about its plutonium stockpile as a confidence-building measure (but not about its HEU stocks). In reports to the IAEA in 2012 and 2013, Japan forgot to include 620kg of plutonium in MOX fuel that was stored unused at an idle power plant in Kyushu. Rectification of the mistake in 2014 generated domestic controversy, and criticism from China.

81 Interview, November 2014.

82 ‘MOX Imports Have Cost at Least ¥99.4bn, Much Higher than Uranium Fuel’, Jiji Press, 22 February 2015.

83 Douglas Birch, ‘The Projected Cost of the Government's Most Expensive Non-proliferation Effort Rises Again’, Center for Public Integrity, 23 April 2015, http://www.publicintegrity.org/2015/04/23/17218/projected-cost-governments-most-expensive-non-proliferation-effort-rises-again.

84 Acton, ‘Wagging the Plutonium Dog’.

85 Masafumi Takubo and Frank von Hippel, ‘Ending Reprocessing in Japan: An Alternative Approach to Managing Japan's Spent Nuclear Fuel and Separated Plutonium’, International Panel on Fissile Materials, November 2013, http://fissilematerials.org/library/rr12.pdf.

86 ‘Japan's Nuclear Fuel Cycle Futures’.

87 Author's interview with Tatsujiro Suzuki, October 2014.

88 Fred McGoldrick, ‘IAEA Custody of Japanese Plutonium Stocks: Strength ening Confidence and Transparency’, Arms Control Today, September 2014.

89 Interview with Tatsujiro Suzuki, October 2014. Suzuki was vice chairman of the Japan Atomic Energy Commission at the time of the policy debate.

90 Ministry of Foreign Affairs of the People's Republic of China, ‘Foreign Ministry Spokesperson Hua Chunying's Regular Press Conference on February 17, 2014’, http://www.fmprc.gov.cn/mfa_eng/xwfw_665399/s2510_665401/2535_665405/t1129283.shtml.

91 Interview in Tokyo, January 2015.

92 ‘Security Implications of the Nuclear Fuel Cycle: Report of the Monterey Eminent Persons Group’, James Martin Center for Non-proliferation Studies, October 2014, http://www.non-proliferation.org/wp-content/uploads/2014/10/141028_nuclear_fuel_cycle_security_implications_lewis.pdf.

93 US Department of Energy, ‘Additional Information Concerning Underground Nuclear Weapon Test of Reactor-Grade Plutonium’, 1994, https://www.osti.gov/opennet/forms.jsp?formurl=document/press/pc29.html. For a discussion of whether the 1962 test was really reactor-grade, see Gregory S. Jones, ‘What Was the Pu-240 Content of the Plutonium Used in the U.S. 1962 Nuclear Test of Reactor-Grade Plutonium?’, Non-proliferation Policy Education Center, 6 May 2013, http://www.npolicy.org/article.php?aid=1212&rtid=2.

94 Twenty years ago, Selig Harrison reported that the amounts were about 40kg from Joyo and 10kg from Monju. See Selig S. Harrison, ‘Unclassified Working Papers’, Appendix 3 in Japan's Nuclear Future: The Plutonium Debate and East Asian Security, Commission to Assess the Ballistic Missile Threat to the United States, 15 July 1996, http://www.fas.org/irp/threat/missile/rumsfeld/pt2_selig.htm. I obtained updated figures from knowledgeable sources in Tokyo in October 2015.

95 Interview with Tatsujiro Suzuki, October 2014.

96 Selig Harrison, ‘North Korea and the Future of East Asia Nuclear Stability’, in N.S. Sisodia, V. Krishnappa and Priyanka Singh (eds), Proliferation and Emerging Nuclear Order in the Twenty-First Century (New Delhi: Academic Foundation, 2009), pp. 49–50.

97 Samuels and Schoff, ‘Japan's Nuclear Hedge’, p. 241.

98 Kazuo Takase et al., ‘Successful Demonstration for Upper Stage Controlled Re-entry Experiment by H-IIB Launch Vehicle’, Mitsubishi Heavy Industries Technical Review, vol. 48, no. 4, December 2011, http://www.mhi.co.jp/technology/review/pdf/e484/e484011.pdf.

99 Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, p. 20.

100 Self and Thompson, ‘Nuclear Energy, Space Launch Vehicles, and Advanced Technology’, p. 173; James L. Schoff, Realigning Priorities: the U.S.–Japan Alliance and the Future of Extended Deterrence (Cambridge, MA: Institute for Foreign Policy Analysis, 2009), p. 45.

101 Self and Thompson, ‘Nuclear Energy, Space Launch Vehicles, and Advanced Technology’, p. 173.

102 Dawson, ‘In Japan, Provocative Case for Staying Nuclear’.

103 Schoff, ‘Realigning Priorities’, p. 47.

104 Ibid., pp. 47–9.

105 I am indebted to James Acton for this observation.

106 Paul Levanthal, quoted in Geoff Brumfiel, ‘Nuclear Proliferation Special: We Have the Technology’, Nature, 25 November 2004, p. 432.

107 Interview with Vladimir Orlov, January 2015.

108 See Windrem, ‘Japan Has Nuclear “Bomb in the Basement”, and China Isn't Happy’.

109 Jeffrey Lewis, ‘N Minus Six Months’, Arms Control Wonk, 6 January 2007, http://lewis.armscontrolwonk.com/archive/1344/n-minus-six-months.

110 Hideo Tamura, ‘Kaku Danto Shisaku ni 3nen Ijo’, Sankei Shimbun, 25 December 2006.

111 US Deputy Director of National Intelligence, ‘National Intelligence Estimate Number 4–66: The Likelihood of Further Nuclear Proliferation’, 20 January 1966, National Security Archive, http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB155/prolif-12.pdf.

112 US Director of Central Intelligence, ‘National Intelligence Estimate Number 4–67: Proliferation of Missile Delivery Systems for Nuclear Weapons’, National Security Archive, 26 January 1967, http://nsarchive.gwu.edu/NSAEBB/NSAEBB155/prolif-14b.pdf.

113 ‘A Primer on the Future Threat, the Decades Ahead: 1999–2020’, quoted in Rowan Scarborough, Rumsfeld's War: The Untold Story of America's Anti-Terrorist Commander (Washington DC: Regnery, 2004), p. 149.

114 See Schoff, ‘Realigning Priorities’, p. 44.

115 Thompson and Self, ‘Nuclear Energy, Space Launch Vehicles, and Advanced Technology’, pp. 165–6.

116 Schoff, ‘Realigning Priorities’, p. 44.

117 Ibid., p. 26.

118 Zbigniew Brzezinski, The Fragile Blossom: Crisis and Change in Japan (New York: Harper and Row, 1972); John J. Mearsheimer, ‘Why We Will Soon Miss the Cold War’, in Andrei G. Bochkarev and Don L. Mansfield (eds), The United States and the USSR in a Changing World (Boulder, CO: Westview Press, 1992); Kenneth N. Waltz, ‘The Emerging Structure of International Politics’, International Security, vol. 18, no. 2, Autumn 1993, pp. 44–79.

119 CIA, ‘Nuclear Weapons Production in Fourth Countries: Likelihood and Consequences’, national intelligence estimate no. 100-6-57, 18 June 1957, National Security Archive, www.gwu.edu/-nsarchiv/NSAEBB/NSAEBB155/prolif-2.pdf. The national intelligence estimate said Japan would ‘probably seek to develop weapons production programs within the next decade’.

120 Poll cited in Solingen, Nuclear Logics, p. 66.

121 Japan Defense Agency, ‘Concerning the Problem of the Proliferation of Weapons of Mass Destruction’, 1995, p. 34, http://www.ucsusa.org/assets/documents/nwgs/1995jdastudy.pdf. In common Japanese fashion, the language employed a double negative to qualify the assertion.

122 See Harrison, ‘North Korea and the Future of East Asia Nuclear Stability’, p. 45; Campbell and Sunohara, ‘Japan’, p. 231.

123 Japanese Ministry of Defense, ‘Defense of Japan 2014’, p. 17, http://www.mod.go.jp/e/publ/w_paper/2014.html.

124 Armed with a 1,000kg warhead, the original Nodong can travel about 900km. Tokyo is probably out of range, but not Nagoya or some parts of western Japan. A variant of the Nodong that was first displayed in 2010 might have a range of 1,600km if the warhead was reduced to 750kg. See Mark Fitzpatrick (ed.), North Korean Security Challenges: A Net Assessment (London: IISS, 2011), p. 135.

125 Matake Kamiya, ‘A Disillusioned Japan Confronts North Korea’, Arms Control Today, May 2003.

126 Izumi and Furukawa, ‘Not Going Nuclear’.

127 Asahi public opinion poll, October 2006, http://www.tv-asahi.co.jp/hst/poll/200610/.

128 Izumi and Furukawa, ‘Not Going Nuclear’.

129 Christopher W. Hughes, ‘North Korea's Nuclear Weapons: Implications for the Nuclear Ambitions of Japan, South Korea, and Taiwan’, Asia Policy, no. 3, January 2007, p. 87.

130 Izumi and Furukawa, ‘Not Going Nuclear’.

131 See Robert Zarate, ‘America's Allies and Nuclear Arms: Assessing the Geopolitics of Non-proliferation in Asia’, Foreign Policy Initiative, 6 May 2014, http://www.foreignpolicyi.org/content/america%E2%80%99s-allies-and-nuclear-arms-assessing-geopolitics-nonproliferation-asia#sthash.CpJqRJwa.dpuf.

132 Interview in Tokyo, November 2014.

133 Nobumasa Akiyama, presentation at IISS workshop in Seoul, 27 October 2014.

134 Interviews in Tokyo, November 2014.

135 Interview in Washington, March 2015.

136 ‘Why Is China Modernizing its Nuclear Arsenal?’, panel discussion at the 2015 Carnegie Nuclear Policy Conference, 24 March 2015, http://carnegieendowment.org/2015/03/24/why-is-china-modernizing/hz37.

137 Brad Roberts, ‘Extended Deterrence and Strategic Stability in Northeast Asia’, National Institute of Defense Studies, 9 August 2013, pp. 30–1, http://www.nids.go.jp/english/publication/visiting/pdf/01.pdf.

138 Interview with a US official, Washington, March 2015.

139 Interviews in Tokyo, January 2015.

140 Solingen, Nuclear Logics, p. 59.

141 US exports to China in 2014 totalled US$124bn, compared to US$67bn to Japan; imports from China totalled US$467bn, compared to US$134 from Japan, according to US Census Bureau figures available at https://www.census.gov/foreign-trade/balance/c5880.html.

142 Samuels and Schoff, ‘Japan's Nuclear Hedge’, p. 245, citing Sankei Shimbun, 22 February 2013.

143 Interview with Michael Green, October 2014. Green, who covered Asia policy for Republican presidential candidate John McCain's campaign, was one of those contacted.

144 Letter from Katsuya Okada to Hillary Clinton, 24 December 2009, unofficial translation, http://icnndngojapan.files.wordpress.com/2010/01/20091224_okada_letter_en.pdf.

145 Roberts, ‘Extended Deterrence and Strategic Stability in Northeast Asia’, p. 25.

146 Michito Tsuruoka, ‘Why the NATO Nuclear Debate Is Relevant to Japan and Vice Versa’, German Marshall Fund of the United States, 8 October 2010, http://www.gmfus.org/publications/why-nato-nuclear-debate-relevant-japan-and-vice-versa.

147 Samuels and Schoff, ‘Japan's Nuclear Hedge’, p. 246.

148 Discussion with Ken Jimbo, November 2014.

149 Japanese Ministry of Defense, ‘National Defense Program Guidelines for FY 2014 and Beyond’, 17 December 2013, http://www.mod.go.jp/j/approach/agenda/guideline/2014/pdf/20131217_e2.pdf.

150 Ministry of Foreign Affairs of Japan, ‘The Guidelines for U.S.– Japan Defense Cooperation’, 27 April 2015, http://www.mofa.go.jp/region/n-america/us/security/guideline2.html.

151 Discussion with Ken Jimbo, November 2014.

152 Justin McCurry and Tania Branigan, ‘Obama Says US Will Defend Japan in Island Dispute with China’, Guardian, 24 April 2014.

153 Bruno Tertrais, ‘Drawing Red Lines Right’, Washington Quarterly, Autumn 2014.

154 Shinzo Abe's remarks at Statesmen's Forum at the Center for Strategic and International Studies, Washington DC, 22 February 2013, http://csis.org/files/attachments/132202_PM_Abe_TS.pdf.

155 Robert A. Manning, ‘The Future of US Extended Deterrence in Asia to 2025’, Atlantic Council, October 2014, http://www.atlanticcouncil.org/publications/reports/the-future-of-us-extended-deterrence-in-asia-to-2025. Aaron L. Friedberg, Beyond Air–Sea Battle: The Debate Over US Military Strategy in Asia (Abingdon: Routledge for the IISS, 2014).

156 Furukawa, ‘Japan's Policy and Views on Nuclear Weapon’, p. 23; interview with US official, March 2015.

157 Zagoria, ‘NCAFP Fact-finding Mission to Seoul, Taipei, Beijing and Tokyo 18 October – 2 November, 2014’.

158 Green and Furukawa, ‘Japan’, pp. 358–9.

159 Pew Research Center, ‘Americans, Japanese: Mutual Respect 70 Years after the End of WWII’, 7 April 2015, http://www.pewglobal.org/2015/04/07/americans-japanese-mutual-respect-70-years-after-the-end-of-wwii/.

160 Mochizuki, ‘Japan Tests the Nuclear Taboo’, p. 314; Green and Furukawa, ‘Japan’, p. 348.

161 Samuels and Schoff, ‘Japan's Nuclear Hedge’, p. 257. A related model would involve relaxing the Three Non-Nuclear Principles overtly to allow the transit of US nuclear-armed ships and aircraft.

162 Dawson, ‘In Japan, Provocative Case for Staying Nuclear’.

163 Kamiya, ‘A Disillusioned Japan Confronts North Korea’, p. 67.

164 ‘Seron chosa: Abe Naikako Shiji … 71.4% Fushiji 21.8%: Kitachosen ni Taishite Atsuryoku Yori Taiwa wo Juushi 57.6%’, Fuji TV, 21 April 2013, http://jin115.com/archives/51944442.html.

165 Solingen, Nuclear Logics, p. 66; Samuels and Schoff, ‘Japan's Nuclear Hedge’, p. 251.

166 Interview with Yukio Satoh, November 2014.

167 Manning, ‘The Future of US Extended Deterrence in Asia to 2025’, p. 4.

168 Kumao Kaneko, ‘Japan Needs No Umbrella’, Bulletin of the Atomic Scientists, vol. 52, no. 2, March– April 1996.

169 Hymans, ‘Veto Players, Nuclear Energy, and Non-proliferation’, p. 180.

170 World Bank, ‘Merchandise Trade (% of GDP)’, http://data.worldbank.org/indicator/TG.VAL.TOTL.GD.ZS.

171 Izumi and Furukawa, ‘Not Going Nuclear’.

172 Reiji Yoshida, ‘National Security Debate Mushrooming Since Oct 9’, Japan Times, 25 November 2006.

173 Brad Roberts, ‘Extended Deterrence and Strategic Stability in Northeast Asia’.

174 See David Santoro, ‘Will America's Asian Allies Go Nuclear?’, National Interest, 30 January 2014, http://nationalinterest.org/commentary/will-americas-asian-allies-go-nuclear-9794; and Zarate, ‘America's Allies and Nuclear Arms’.

175 Elbridge Colby, ‘Choose Geopolitics Over Non-proliferation’, National Interest, 28 February 2014, http://nationalinterest.org/commentary/choose-geopolitics-over-non-proliferation-9969?page=show.

176 Quoted in Mitsuru Kurosawa, ‘East Asian Regional Security and Arguments for a Nuclear Japan’, paper presented at the Hiroshima Peace Institute workshop ‘Prospects for East Asian Nuclear Disarmament’, Hiroshima, 11–12 March 2004.

177 David Frum, ‘Mutually Assured Disruption’, New York Times, 20 October 2006.

178 Katsuhisa Furukawa, ‘Japan's Nuclear Option’, in James J. Wirtz and Peter R. Lavoy (eds), Over the Horizon Proliferation Threats (Stanford, CA: Stanford University Press, 2012), p. 28.

179 Campbell and Sunohara, ‘Japan’, p. 246.