The Chinese Civil War (1927–1950) was a civil war in China fought between forces loyal to the government of the Republic of Chinaled by the Kuomintang and forces of the Communist Party of China led by Mao Zedong. The war began in April 1927 and essentially ended in 1950. The conflict eventually resulted in two de facto states, the Republic of China in Taiwan and the People's Republic of China in mainland China, both claiming to be the legitimate government of China.
The civil war continued intermittently until late 1937, when the two parties joined to counter a Japanese invasion. After WWII the civil war resumed until 1949—with the newly founded People's Republic of China controlling mainland China and the Republic of China's jurisdiction being restricted to Taiwan.
The Kuomintang defeat is attributed to several factors including corruption - Chiang wrote in his diary on June 1948 that the KMT had failed, not because of external enemies but because of rot from within.
Strong initial support from the U.S. for nationalist forces diminished, and then, stopped because of KMT corruption and because of concerns over communism in China. Secy. Of State Dean Acheson and President Harry Truman were criticized for having “lost China” to the communists.
Mao Zedong—Communist Party leader until his death in 1976
Chiang Kai-shek (1887-1975) (a.k.a Jiang Jieshi)
In office 1928 – 1931
Sino-American or Chinese–US relations refer to international relations between the U. S. and the government of People's Republic of China. Most analysts characterize present Sino-American relations as being complex and multi-faceted. The United States and the People's Republic of China are usually neither allies nor enemies; the US government and the military establishment do not regard the Chinese as an adversary but as a competitor in some areas and a partner in others.
Until the 1970s, the United States recognized the Republic of China on Taiwan as the legitimate government of mainland China and did not maintain diplomatic relations with the communist regime of the People's Republic of China.
Nixon pursues a policy of détente in the 1970s and relations with mainland China formally begin.
As of 2011, the United States has the world's largest economy and China the second largest. China has the world's largest population and the United States has the third largest. The two countries are the two largest consumers of motor vehicles and oil, and the two greatest emitters of greenhouse gases.
Relations between the People's Republic of China and the United States have been generally stable with some periods of tension, most notably after the breakup of the Soviet Union, which removed a common enemy and ushered in a world characterized by American dominance. There are also concerns relating to human rights in the People's Republic of China and the political status of Taiwan. China and the US are the largest mutual trading partners, excluding the European Union.
China is also the largest foreign creditor for the United States. China's challenges and difficulties are mainly internal, and there is a desire to maintain stable relations with the United States. The Sino-American relationship has been described by top leaders and academics as the world's most important bilateral relationship of the 21st century.