Following the Second World War, Yasuhiro Nakasone was highly critical of Prime Minister Shigeru Yoshida's foreign policies, including the Japan-US Security Treaty, and actively campaigned for an increase in Japan’s self-defense capability and related amendments to the constitution. However, as an opposition member, Nakasone could not directly engage in formulating policies. On 10 December 1954, the inauguration of Ichiro Hatoyama’s Cabinet brought an end to Nakasone’s time in opposition. Nakasone served as Defense Minister in the Cabinets of Hatoyama, Ishibashi, Kishi, Ikeda, and Sato. He also served as Secretary of the Science and Technology Agency in the Second Kishi Cabinet, and as Chairman of the Atomic Energy Commission and Transport Minister in the Sato Cabinet.
As a ruling party lawmaker and Minister of State who was determined to change Japan's security policy, Nakasone explored a range of issues including constitutional amendments, peaceful uses of nuclear energy, space development, and the Okinawa problem. This paper examines his involvement, and evaluates changes in his arguments and his role, thereby filling some of the gaps in research on Yasuhiro Nakasone.