evidence: The Cairo Declaration issued by China, the United States and the United Kingdom on December 1, 1943 stated that it was the purpose of the three allies that all the territories Japan had stolen from China, such as Northeast China, Taiwan and the Penghu Islands, should be restored to China. [...] [2] Between September 4 and 8, 1951, the United States gathered a number of countries in San Francisco for what they described as the San Francisco Peace Conference. Neither the PRC nor the Soviet Union received an invitation. The treaty signed at this meeting, commonly known as the Treaty of San Francisco, included an article under which Japan renounced all rights, title and claim to Taiwan and the Penghu Islands. This treaty contravened the provisions of the Declaration by United Nations signed by 26 countries - including the United States, the United Kingdom, the Soviet Union and China - in 1942, the fundamental principles of the UN Charter, and the basic norms of international law. The PRC was excluded from its preparation, drafting and signing, and its rulings on the territory and sovereign rights of China - including the sovereignty over Taiwan - are therefore illegal and invalid. The Chinese government has always refused to recognize the Treaty of San Francisco, and has never from the outset deviated from this stance. Other countries, including the Soviet Union, Poland, Czechoslovakia, the Democratic People's Republic of Korea, Mongolia, and Vietnam, have also refused to recognize the document's authority.