The Cairo Conference held 70 years ago between leaders of the United States, the United Kingdom and China, resulted in a declaration broadcast through radio on Dec 1, 1943, that all the territories Japan had taken from China such as northeastern China and Taiwan, including the Diaoyu Islands, should be returned to China.

Japan finally signed the Instrument of Surrender on Sept 2, 1945, and by doing so accepted the terms of the Potsdam Proclamation of July 26, 1945. That proclamation stipulated, in clause 8, that the terms of the Cairo Declaration shall be carried out and that Japanese sovereignty shall be limited to four specified islands, which did not include the Diaoyu Islands.

History tells us that the next steps were not so straightforward, especially in relations between China and the US. There followed a testing period in international relations, including an unhelpful 1951 San Francisco Peace Treaty, which failed to recognize China's territorial interests as both the Chinese mainland and Taiwan were absent.