Following the October 1945 Japanese surrender ceremonies in Taipei, the capital of Taiwan Province, Taiwan once again became the governing polity of China during the period of military occupation. In 1949, after losing control of most of mainland China following the Chinese Civil War, and before the post-war peace treaties had come into effect, the ROC government under the KMT withdrew to occupied Taiwan. Chiang Kai-shek declared martial law. An argument has been made that Japan formally renounced all territorial rights to Taiwan in 1952 in the San Francisco Peace Treaty, but neither in that treaty nor in the peace treaty signed between Japan and China was the territorial sovereignty of Taiwan awarded to the Republic of China. The treaties left the status of Taiwan—as ruled by the ROC or PRC—deliberately vague, and the question of legitimate sovereignty over China is why China was not included in the San Francisco Peace Treaty. This argument is not accepted by those who view the sovereignty of Taiwan as having been legitimately returned to the Republic of China at the end of the war.</ref> Some argue that the ROC is a government in exile, while others maintain it is a rump state.