From the Document: "Taiwan, which officially calls itself the Republic of China (ROC), is a democracy of 23 million people located across the Taiwan Strait from mainland China. Its government claims 'effective jurisdiction' over the island of Taiwan, the archipelagos of Penghu, Kinmen, and Matsu, and other outlying islands. Taiwan also claims disputed geographic features in the East and South China Seas. The People's Republic of China's (PRC's or China's) stated determination to unify with Taiwan at an unspecified future date, combined with U.S. security commitments related to Taiwan, make Taiwan the hotspot that could most plausibly draw the United States and China into armed conflict. U.S.-Taiwan relations have been unofficial since January 1, 1979, when the United States established diplomatic relations with the PRC and broke them with self-ruled Taiwan, over which the PRC claims sovereignty."
CRS In Focus, IF10275
Congressional Research Service: https://crsreports.congress.gov/