The Taiwan issue has played a major role in the understanding China and the US have enjoyed over the years.  "The Shanghai Communiqué" -- issued in 1972, during President Richard Nixon's visit to China -- acknowledged that there is only One China.

Seven years later, the US established diplomatic relations with China, and cut its official ties with Taiwan. However, the US Congress passed the "Taiwan Relations Act", granting the island the same privileges as a sovereign nation. In 1982, Beijing and Washington signed another "joint communiqué", stating that the US would not sell Taiwan more weapons than it did before 1979.