The Two Dimensions of the Post-war Territorial Status of the Ryukyu Islands

Abstract Ryukyu was a kingdom that maintained tributary relations to China for more than 500 years until it was invaded by Japan in 1879 and renamed Okinawa Prefecture by the Meiji government. Article 3 of the 1951 San Francisco Peace Treaty separated Ryukyu from Japan’s territory. It was planned to be within the trusteeship system of the United Nations, with the United States (US) as the sole administering authority. There were two schools of thought regarding the territorial status of the Ryukyu Islands after World War II: Trusteeship, and the US occupation of the Ryukyu Islands. Through the multidisciplinary perspective of integrating international law and historical archives, the post-war legal status of the Ryukyu Islands appears to be two-dimensional, namely, the potential territory of the trusteeship and the de facto military occupation. Dulles’ proposal for residual sovereignty at the San Francisco Conference was intended to legitimize the US-Japan disposition of Ryukyu from the 1950s to the 1970s. However, through an analysis of theories and judicial practices related to residual sovereignty, it is found that the application of residual sovereignty to the ultimate territorial disposition of the Ryukyu Islands between the US and Japan will only lead to legal paradoxes, and can hardly form the legal basis for this disposition.