A Study of the Issues of Nuclear Submarine Visits to Japan: Focusing on the Period 1960-1964

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K01477
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 06010:Politics-related
• Research Institution: Kyushu University
• Principal Investigator: Nakashima Takuma 九州大学, 法学研究院, 教授 (20380660)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 原子力潜水艦の寄港 / 核兵器の持ち込み問題 / 日米安保体制 / アメリカの同盟政策 / 日本外交史

Outline of Final Research Achievements

This study focuses on the issue of nuclear submarine port call to Japan in 1964 as a policy case in which the development of new nuclear weapons by the U.S. during the Cold War conversely made it difficult for the Japanese government to respond in domestic politics. I have clarified the political process leading to the visit of Seadragon, the US Navy's nuclear powered submarine to Japan. This study examined ①U.S. process for considering nuclear submarine visits to allied countries,②the Japan-U.S. summit meeting in 1961, and ③the Japan-U.S. talks and domestic political process leading up to the nuclear submarine's visit in Sasebo in 1964. From the study, I presented a certain structure surrounding the issue of nuclear weapons introduction, in which changes in U.S. nuclear weapons technology occurred where Japan's existing legal system had not anticipated, and the government was forced to consider the issue under the legal system after the issue became a political issue in the Diet.

Free Research Field

外交史／日本政治外交史

Academic Significance and Societal Importance of the Research Achievements

冷戦時代に存在したと考えられる上記の構図の存在を、日米関係と国内政治の相互作用に着目しながら実証的に明らかにすることは、憲法第９条と日米安保条約をともに維持しながら展開された戦後日本の外交・安全保障政策の実態解明につながる。また、日米安保体制をめぐる法と政治の葛藤の中で行われた日本政府の高度な政治判断の歴史を理解することで、今後の日本外交に関する示唆を得ることができると考えられる。