Japanese Scientists’ Critique of Nuclear Deterrence Theory and Its Influence on Pugwash, 1954–1964 ✣ Akira Kurosaki Japan and Pugwash from a Transnational Perspective In July 1957, 22 scientists from both sides of the Iron Curtain gathered in the quiet village of Pugwash in Nova Scotia to discuss nuclear dangers and ways to establish world peace. This meeting led to the founding of a loose- knit transnational coalition of scientists known later as the Pugwash Conferences on Science and World Affairs (Pugwash, for short). During the Cold War, Pugwash provided scientists with a forum to discuss issues related to world peace and security. It also served as an informal communication channel be- tween East and West.1 In 1995, Pugwash, together with its former president and one of its founding members, Joseph Rotblat, won the Nobel Peace Prize “for their efforts to diminish the part played by nuclear arms in international politics and in the longer run to eliminate such arms.”2 As Pugwash’s activities expanded and its participants increased, national groups sprang up in several countries, including Japan. In the late 1950s, the Japanese affiliate was created under the leadership of three prominent theo- retical physicists: Hideki Yukawa (1907–1981), who received the Nobel Prize in Physics in 1949; Sin-Itiro¯ Tomonaga (1906–1979), who received the No- bel Prize in 1965; and Shoichi¯ Sakata (1911–1970). The Japanese branch sent scientists to international Pugwash meetings and kept scientists and citizens in Japan informed about Pugwash activities. In 1962, Yukawa, Tomonaga, and Sakata also established the Kyoto Conference of Scientists (KCS) in line with 1. On the history of Pugwash, see Joseph Rotblat, Pugwash: A History of the Conferences on Science and World Affairs (Prague: Czechoslovak Academy of Sciences, 1967); and Joseph Rotblat, Scientists in the Quest for Peace (Cambridge, MA: MIT Press, 1972). 2. “The Nobel Peace Prize 1995,” 13 October 1995, Nobelprize.org, http://www.nobelprize.org/nobel _prizes/peace/laureates/1995/press.html. Journal of Cold War Studies Vol. 20, No. 1, Winter 2018, pp. 101–139, doi:10.1162/jcws_a_00802 © 2018 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology 101 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/jcws_a_00802 by guest on 26 September 2021 Kurosaki Pugwash. Its seminars and conferences held in Japan became a major domestic activity for the Japanese Pugwash group.3 What made the Pugwash affiliate in Japan distinctive was its firm oppo- sition to the strategic concept of nuclear deterrence. In the 1950s the United States and the Soviet Union were expanding and modernizing their nuclear ar- senals. Having competed to develop hydrogen bombs in the early 1950s that would be far more destructive than fission bombs, the superpowers undertook the development of new strategic delivery vehicles such as intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs). Although the United States maintained its strategic superiority over the Soviet Union, the two countries threatened each other with their ever more capable nuclear forces. Given their deep-seated mutual distrust, negotiated nuclear disarmament became nearly impossible, and a “balance of terror” became an axiom of peace.4 By contrast, the Japanese Pugwash group called for the abo- lition of nuclear weapons and criticized the nuclear deterrence theory that provided powerful justification for living with nuclear weapons. The complete rejection of nuclear deterrence theory by Pugwash scientists in Japan is notable for two reasons. First, these scientists pioneered a compre- hensive critique of nuclear deterrence in Japan in the early 1960s. Their the- oretical contributions marked a new phase in anti-nuclear activism in Japan. After the incident in 1954 when a Japanese fishing vessel known as the Lucky Dragon (FukuryuMaru¯ ) was accidentally showered with radioactive fallout from a U.S. thermonuclear explosion, anti-nuclear sentiment in Japan grew rapidly, encompassing all types of people and groups and coalescing into a nationwide public campaign by the late 1950s. Against this backdrop, the Japanese government began opposing the nuclear arms race and declared a 3. For an overview of the history and activities of the Japanese group, see Hideki Yukawa, Sin-Itiro¯ Tomonaga, and Shoichi¯ Sakata, eds., Heiwa jidai o soz¯ o¯ suru tameni: Kagakusha wa uttaeru (Tokyo: Iwanami Shoten, 1963); Hideki Yukawa, Sin-Itiro¯ Tomonaga, and Shoichi¯ Sakata, Kakujidai o koeru: Heiwa no soz¯ oomezashite¯ (Tokyo: Iwanami Shoten, 1968); and Hideki Yukawa, Sin-Itiro¯ Tomonaga, and Toshiyuki Toyoda, eds., Kakugunshuku eno atarashii kos¯ o¯ (Tokyo: Iwanami Shoten, 1977). This article is partly based on the author’s published works on the Japanese group, with a focus on its opposition to the concept of nuclear deterrence in the 1950s and 1960s: Akira Kurosaki, “Nihon ni okeru kakuyokushi-ron no tanjo:¯ Paguwottshu kaigi to Nihon no kagakusha,” Dojidaishi¯ Kenkyu¯,No. 2 (2009), pp. 3–20; and Akira Kurosaki, “‘Kaku no kasa’ heno izon ni aragatta Nihon no kagakusha, 1963–1968,” Hogaku¯ , Vol. 76, No. 6 (January 2013), pp. 51–76. Brief descriptions of the Japanese group’s activities are presented in English in Shigeru Nakayama, “The Scientists-Led Peace Move- ment,” in Shigeru Nakayama, Kunio Goto,¯ and Hitoshi Yoshioka, eds., A Social History of Science and Technology in Contemporary Japan,Vol.2,Road to Self-Reliance 1952–1959 (Melbourne: Trans Pacific Press, 2005), pp. 339–341; and Morris Low, Science and the Building of a New Japan (New York: Palgrave Macmillan, 2005), pp. 137–140. 4. Ronald E. Powaski, March to Armageddon: The United States and the Nuclear Arms Race, 1939 to the Present (New York: Oxford University Press, 1987), chs. 5–7. 102 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/jcws_a_00802 by guest on 26 September 2021 Japanese Scientists’ Critique of Nuclear Deterrence Theory non-nuclear weapons policy, which crystallized in 1968 as the Three Non- Nuclear Principles (Hikaku san gensoku) of not possessing, manufacturing, or allowing the introduction of nuclear weapons into Japan.5 Although popular demand for banning fission and hydrogen bombs was antithetical to the idea of relying on nuclear weapons as a deterrent, even those who wanted to pro- hibit the bomb had failed to come to grips with the concept of deterrence until Pugwash scientists in Japan formulated a systematic critique of this strategic notion. The other reason the Pugwash affiliate in Japan stood out was its transna- tional activism; namely, its steadfast opposition to arms control proposals dis- cussed at Pugwash that sought to stabilize nuclear deterrence. In the late 1950s and early 1960s, general and comprehensive disarmament was a major discus- sion topic at Pugwash meetings. The role of nuclear deterrence in the disar- mament process became a contentious issue mainly between U.S. and Soviet scientists. By the mid-1960s, however, influential U.S. and Soviet Pugwash participants accepted the notion that stable mutual deterrence between the United States and the Soviet Union had to be maintained to prevent a nu- clear war, as well as facilitate arms control and disarmament. Nevertheless, the Japanese Pugwash group continued to criticize the idea of mutual deterrence at Pugwash, as well as in Japan, throughout the Cold War. This article highlights the unique role of Japanese scientists both in Japan and at Pugwash by analyzing the origins and development of their critique of nuclear deterrence and proposing two arguments. First, the distinctive out- look of Japanese Pugwash members emerged out of close contact with their colleagues abroad as well as public opinion in Japan against nuclear weapons and war in general. This confluence of the transnational and the domestic cat- alyzed the conception of a radical alternative to nuclear deterrence theory. Sec- ond, the critique put forth by the Japanese Pugwash group strongly suggests that the consensus at Pugwash was not necessarily accepted by all national affiliates; rather, the nuclear deterrence theory embraced by Pugwash leaders prompted the Japanese members to devise counterarguments. Although pre- vious studies have overlooked the small voice of dissent raised by Pugwash scientists in Japan during the Cold War, this article examines their critique in detail to show that the Pugwash movement was not only a unified front of scientists across borders but also an open forum that facilitated the formation 5. Akira Kurosaki, Kakuheiki to Nichi-Bei kankei: Amerika no kakufukakusan seisaku to Nihon no sen- taku, 1960–1976 (Tokyo: Yushisha,¯ 2006); and Ayako Kusunoki, “The Sato Cabinet and the Making of Japan’s Non-nuclear Policy,” Journal of American-East Asian Relations, Vol. 15 (2008), pp. 25–50. 103 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/jcws_a_00802 by guest on 26 September 2021 Kurosaki and exchange of ideas for peace.6 Close analysis of the Pugwash activism in Japan helps us better understand that the transnational scientific movement as a locus of intellectual cross-fertilization in face of the nuclear peril. The article first examines the responses of Yukawa, Tomonaga, and Sakata, as well as the Japanese scientific community as a whole, to the dan- ger of nuclear weapons in the late 1940s and early 1950s. It also traces the development of Japan’s nuclear weapons policy in order to discuss the politi- cal, social, and diplomatic contexts of post–World War II Japan in which the Japanese Pugwash group was formed in the late 1950s. The focus of discussion then moves to the question of nuclear deterrence that became contentious at Pugwash during the late 1950s and early 1960s. Of particular importance was Tomonaga’s critical analysis of nuclear deterrence published in 1961, which became a common starting point for the Japanese Pugwash group. In examin- ing the first KCS statement in 1962 and others made by the Japanese Pugwash group, the article explains how the Japanese members challenged the intellec- tual hegemony of nuclear deterrence theory at Pugwash in the 1960s and 1970s.