The University Of Reading The Development of US Extended Nuclear Deterrence over Japan: A Study of Invisible Deterrence between 1945 and 1970 Hiroshi Nakatani PhD, Politics Department of Politics and International Relations February 2019 Declaration of Original Authorship Declaration: I confirm that this is my own work and the use of all materials from other sources has been properly and fully acknowledged Hiroshi Nakatani 1 This thesis is dedicated to the late Colonel Matuo Keiichi for his service to Japan. 2 Acknowledgments Throughout my PhD life, many people and institutions have thoughtfully supported and encouraged my work. It is probably most appropriate to begin by acknowledging the School of Politics, International Relations and Economics, University of Reading for its financial assistance for three years. I am also extremely indebted to the Lyndon Johnson Library, the British Association for Japanese Studies and Reading Travel Research Grants for providing me with research grants, which enabled me to travel and research abroad. Without their generous financial support, this research project would not have been possible. I would also like to express my appreciation to my supervisors. I have been fortunate to have three supervisors. It was my greatest honour to work under Professor Beatrice Heuser, for whom I came to Reading. She has taught me many invaluable things which otherwise I could have never learned. She has taught me how to conduct great research and treat your students in particular. As a matter of fact, finding a greater supervisor than her can be more difficult to finish a PhD. I would also like to thank Professor Alan Cromartie for his supervision and patience. His critical comments have shaped my work, making it readable. Professor Tom Long has been a very dedicated supervisor. His advice is always encouraging, concise and precise. I am immensely indebted to Professor Stefan Wolff and Dr Masashi Okuyama for advising me to come back to the UK for my doctoral work. I will prove that their foresight is right. I am also grateful to Professor Fintan Hoey, who encouraged me to apply for the Nuclear Boot Camp in Seoul through which I gained a lot of practical feedback for this thesis. Meeting another like-minded fellow in Washing D.C. was my precious memory. My great British friend, Jack Harding, also deserves a mention. I truly appreciate his comradeship. I probably owe him an apology for making him endure my really weird jokes. I look forward to telling him ―But you are not a great doctor!‖ My gratitude naturally goes to Mr. and Mrs. 3 Richardson for providing me with a comfortable room. They are always compassionate and caring. I would also like to thank people who gave me not only a great time but also some new perspectives over wine and beer at pubs and bars. This is last but not least, I owe a huge debt of gratitude to my parents. I just could not thank them enough. I will follow what they have always told me. We are the guardians of Japan. Now it is my turn to serve our country. 4 Table of Contents Abbreviation 6 List of Chart, Map and Table 7 Abstract 8 Chapter One: 9 Introduction Chapter Two: 54 Background Factors: From a Former Evil Enemy to a Virtual Ally Chapter Three: 110 The Nuclearisation of US allies and Japan‘s Perceptions of a Nuclear Base Chapter Four: 161 The First Chinese Nuclear Test and the US Nuclear Umbrella over Japan Chapter Five: 201 The Reversion of the Bonins and Ryukyus: The Completion of Invisible Extended Nuclear Deterrence and Its Theoretical Mechanism Chapter Six: 263 The Japanese Secret Nuclear Studies in the 1960s: Elite Perceptions Chapter Seven: 309 Conclusion: Long Peace or War Avoidance Bibliography 342 5 Abbreviation CIA Central Intelligent Service CINCPAC Commander in Chief Pacific END Extended Nuclear Deterrence EURATOM European Atomic Energy Community GSDF Ground Self-Defence Force IAEA International Atomic Energy Agency ICBM Inter-Continental Ballistic Missile IISS International Institute of Strategic Studies IR International Relations (as a descipline) IRBM Intermediate Range Ballistic Missile JCS Joint Chief of Staff JDA Japan Defence Agency JSDF Japan Self Defence Force MLF Multilateral Force MOD Ministry of Defence MOFA Ministry of Foreign Affairs MRBM Medium Range Ballistic Missile NATO North Atlantic Treaty Organization NPT Non-Proliferation Treaty NSC National Security Council SEATO Southeast Asia Treaty Ognisation SLBM Submarine Launched Ballistic Missile UN United Nations USA United States of America (as a country) US United States (as an adjective of USA) UK United Kingdom 6 List of Figure, Maps and Tables I.A. Map: Countries under the US Nuclear Umbrella State I.B. Map: Current Membership of the NPT I.C. Map: Estimate of Global Nuclear Weapons in January 2018 (SIPRI Year Book 2018) II. List of Key Events III.A. Table: Proliferation Drivers and Barriers III. B. Table: Japanese views of Effectiveness of Various Means for Japan‘s Security III. C. Japanese views of an Independent Japanese Nuclear Deterrent, 1966-1973 III. D. Table: US/ Soviet Nuclear Weapons Inventories, 1949-1952. III. E. Table: The Numbers of Troops of US Forces in Japan and SDF III. F. Table: Key Components of Invisible END III.G Table: Estimate of Global Nuclear Weapons in January 2018 (SIPRI Year Book 2018) IV.Figure: Military Expenditure as Share of GDP 7 Abstract This thesis seeks to offer a novel theoretical and empirical insight into the unique form of the United States (US) extended nuclear deterrence (END) －also known as a nuclear umbrella－provided to Japan. In contrast to the main trend of nuclear weapons deployment in America‘s close allies during the Cold War, Japan was only the key allied state that never hosted US nuclear weapons on its soil throughout the Cold War. Japan, instead, relied on US END backed by strategic forces mainly at sea. US END over Japan was thus ―invisible‖ in that US nuclear weapons were not forward-deployed. This situation has not changed since it was developed in the 1960s. The thesis is an essentially historical project but its main aim is to understand US END over Japan today. Its approach is to use history as a tool to understand the present. The thesis unravels the complex developments of such deterrence between 1945 and 1970. More specifically it seeks to understand under what circumstances Japan came under the US nuclear umbrella and what factors have shaped ―Invisible‖ END. The primary argument of this thesis is that public anti-military and nuclear sentiment in Japan shaped by its historical experience in the devastating World War Two significantly influenced the strategic calculations of Japanese leaders as well as American leaders. Key events in the foregoing period set social and political conditions on strategy making of Japan even today. The thesis will specifically examine the formation process of Japan‘s non-nuclear path chosen. In order to understand the non-nuclear path taken, the thesis will also examine the meaning of the Japan‘s alternative nuclear path. In fact there were some Japanese leaders such as Prime Minister Eisaku Sato, who clearly saw strategic value in nuclear deterrence. ―Invisible‖ END was arguably a product of political compromise for Japan. 8 Chapter One Introduction You have to believe in two impossible things before breakfast: someone will use nuclear weapons; someone will use nuclear weapons on your behalf. ―Edward Luttwak1 This thesis will explore the peculiarity of United States (US) extended nuclear deterrence (END) over Japan with a particular focus on a period between 1945 and 1970. It seeks to provide a novel theoretical and practical insight into what the author terms ―Invisible‖ US END over Japan constituted by strategic forces mainly at sea (submarine launched ballistic missile: SLBM) and to a lesser extent strategic bombers stationed in the US territory.2 It is invisible in the sense that US nuclear weapons were never deployed in the mainland of Japan at any period despite the fact that the US military certainly had plans to place nuclear weapons in Japan. Interestingly such plans were never implemented. While the approach of the thesis is essentially history-oriented, it employs history as a tool to understand the present. Where we stand today has grown out of the past and thus, ―knowledge of the past is prerequisite to an understanding of the present.‖3 Historically grounded analysis is essential for contextual understanding. Ignoring history essentially fails to appreciate the current social and political contexts within which present-day discourses and practices operate as they are formed and institutionalized over time. Drawing on historical insights, this analysis is the first attempt of its kind to theorise ―Invisible‖ END; hence it will examine not only how this concept came to 1 Author‘s exchange with Edward Luttwak before his interview by Bungei Shinjuat the Bungei Shunju Building in Tokyo, 12 October 2018. 2 See for example Morton H. Halperin: Contemporary Military Strategy (Boston: Little Brown and company., 1967), pp. 122-123. 3 Michael Howard: The Lessons of History (Oxford: Oxford U.P., 1991, ppb. 1993), p.9. 9 emerge in the first place and developed but also how it functions in theory. The effect of the invisibility of extended nuclear deterrence has been overlooked, and it has not been adequately theorised. This thesis specifically looks at the formation process of Japan‘s non-nuclear path and the peculiar form of US END. Drawing on multinational archival research in Japan, the USA and the United Kingdom (UK) done by the author, it sets out to empirically account for how Japan came under the US nuclear protection and what factors have shaped ―Invisible‖ END.