The 1970s saw many switches in diplomatic recognition from the Republic of China to the People's Republic of China. After World War II, the Republic of China had been one of the founding members in the United Nations and held China's seat on the Security Council until 1971, when it was expelled by General Assembly Resolution 2758 and replaced in all UN organs with the People's Republic of China government.  Since the 1980s, the number of nations officially recognizing the Republic of China has decreased to 19. The People's Republic of China refuses to maintain diplomatic relations with any government which formally recognizes the Republic of China, leading to a complex political status of Taiwan . United States troops were stationed in Taiwan after the victory of the Communists in mainland China in order to aid in the defense of Taiwan against invasion by the People's Republic of China. The United States military continued to be stationed in Taiwan until diplomatic relations were broken with the Republic of China in 1979 but to this day maintains a significant intelligence presence.
What happened first: General Assembly Resolution 2758 or diplomatic relations between Taiwan and PRC were broken?
General Assembly Resolution 2758