The National Interest:
No country is more threatened by China’s growing military and economic power than the island of Taiwan. Beijing has always considered Taiwan a renegade province that it vows to once again control.
For most of their history since 1949, however, China did not have the military power to conquer Taiwan by force. Indeed, for many decades Taiwan’s military was qualitatively superior to the mainland’s. Furthermore, even after the United States established diplomatic relations with the People’s Republic of China, it has promised (somewhat ambiguously) to defend Taiwan from a Chinese invasion.
This was often backed up in action such as when Bill Clinton sent two U.S. aircraft carriers into the Taiwan strait after China tried to intimidate Taipei with missile tests around the island in the mid-1990s.
