Taiwan, also known as the Republic of China, was a pre-War country, and one of the rivals of the People's Republic of China. The Republic itself was officially established in 1912 after the overthrow of the Qing Dynasty. The government of the nation, the bulk of its armed forces and many nationalist civilians fled the Chinese mainland to the island of Formosa/Taiwan following their failure to put down China's communist revolution. The Republic technically continued on the island after 1949, while the continental territory in its entirety was dominated by Red China. It is unknown if Taiwan was annexed by the People's Republic of China during the Resource Wars, or perhaps even before.
Sometime shortly after P.A.M.'s activation in 2067, the Taiwan Strait region was destabilized during the Pascale Incident. Little is known about the incident except that matters were apparently stabilized following corrective measures taken by the U.S. in the Taiwan Strait region.