In 1943, the global context was undergoing complex developments, and World War II had entered its most brutal phase. To consider several important world issues related to territorial borders, representatives from Great Britain, the United States, and China met in Cairo (Egypt) on November 27, 1943, in what history calls the Conference.
This conference concluded with a joint statement, which included the following passage:“Japan must be removed from all Pacific islands that it has seized or occupied since the start of World War I in 1914 And all the territories that Japan had seized from China, such as Manchuria, Taiwan, and Penghu, would be returned to the Republic of China.”. Thus, China's territory has been clearly demarcated, and there is no connection whatsoever to the sovereignty of the Hoang Sa and Truong Sa Islands.
Furthermore, the Cairo Declaration did not mention the sovereignty of any nation over the Paracel and Spratly Islands Because these two archipelagos have been under the sovereignty of the Vietnamese State for a long time, at least since the 17th centur There is historical evidence proving that sovereignty belongs to the State of Vietnam. Next, in 1945, as World War II gradually drew to a close, the world had many issues to address with the victorious powers, such as territorial disputes and the division of spheres of influence.