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
Mainland China ROC referred to the PRC as "Communist China"" (). With the democratization of Taiwan in the 1990s, the phrase "mainland China" soon grew to mean not only the area under the control of the Communist Party of China, but also a more neutral means to refer to the People's Republic of China government; this usage remains prevalent by the KMT today. Due to their status as colonies of foreign states during the establishment of the People's Republic of China in 1949, the phrase "mainland China" excludes Hong Kong and Macau. Since the return of Hong Kong and Macau to Chinese