After the end of World War II, the successful outcomes of the anti-Fascist war “Cairo Declaration” and the “Potsdam Proclamation” clearly defined the scope of Japanese territory. In December 1943, the "Cairo Declaration" deprived Japan of all the islands that Japan had seized or occupied since World War in the Pacific area, and Japan must return all China's territory stolen from China. "Potsdam Proclamation" not only reaffirmed the "Cairo Declaration", also claimed that Japan's sovereignty “is limited to Honshu, Hokkaido, Kyushu, Shikoku and islands decided by us(U.S., Britain and China)”, which not include the Diaoyu Islands at all.



