History of the Republic of China its remaining islands in Fujian as vital for any future campaign to defeat the PRC and retake mainland China. On 3 September 1954, the First Taiwan Strait Crisis began when the PLA started shelling Quemoy and threatened to take the Dachen Islands. On 20 January 1955, the PLA took nearby Yijiangshan Island, with the entire ROC garrison of 720 troops killed or wounded defending the island. On January 24 of the same year, the United States Congress passed the Formosa Resolution authorizing the President to defend the ROC's offshore islands. The First Taiwan Straits crisis ended in March 1955 when
Politics of the Republic of China this structure remains in place, the President Lee Teng-hui in 1991 unofficially abandoned the government's claim of sovereignty over mainland China, stating that they do not "dispute the fact that the Communists control mainland China." However, the National Assembly has not officially changed the national borders, as doing so may be seen as a prelude to formal Taiwan independence (the People's Republic of China has threatened to start a war if the government of Taiwan formalizes independence). It should be noted that neither the National Assembly nor the Supreme Court has actually defined what the term "existing national boundaries," as