In 1950, after the outbreak of the Korean War, United States President Harry S. Truman said that it would be a direct threat to the United States' security in the western Pacific area if the Communist forces occupied Taiwan and that "the determination of the future status of Formosa must await the restoration of security in the Pacific, a peace settlement with Japan, or consideration by the United Nations.
"[1] This statement of Truman is generally regarded as the origin of the Theory of the Undetermined Status of Taiwan.
It renounced all right, title and claim to Taiwan and the Pescadores without explicitly stating the sovereignty status of the two territories.
[3] The Theory of the Undetermined Status of Taiwan is supported by some politicians and jurists to this day.
[4][5][6] The theory does not apply to Kinmen or the Matsu Islands, which are also controlled by the government of the Republic of China.