Using a historical approach based on newly declassified materials, I attempt to explain the correlation or contradiction between the open “Korea Clause” of 1969 and the secret “Korean Minute” of 1960, both of which were issued by the US-Japan alliance regarding the security of the Republic of Korea (ROK). The existing literature has emphasized the Korea Clause in explaining the Japanese commitment to the security of the ROK and the Japan-ROK military connection. However, I argue that the Korea Clause was merely political rhetoric initiated by Japan to neutralize the written Korean Minute. One of the key aims of US military policy toward Northeast Asia was to secure a free hand in using US forces and bases in Japan. In this context, the Korean Minute backed by the authority of the United Nations legalized the right of US forces to carry out sorties without prior consultation with the Japanese government in case of a Korean crisis. While Japan attempted to terminate the Korean Minute by politicizing it, the United States adopted a stance of benign neglect against it, especially by maintaining the United Nations Command. The Korean Minute remains valid today, and the US- Japan-ROK triangle continues to function legally based on it.