Locked in a common fight against Imperial Japan, the United States and Nationalist China became allies, but significant fissures in their relationship soon developed. Neither ally would accommodate each otherâ¤s core interests in strategies necessary to win the war. This disconnect continued after Japanâ¤s surrender, as the United States pressed Chinese Nationalists and Communists to join a coalition government that neither wanted. During the civil war, the United States supported the Nationalists, but never to the degree they thought mattered. After the Communist triumph, America served its national security and anti-Communism, by helping the Nationalists defend Taiwan, but hedged against assisting Chiang Kai-shek to reconquer the mainland. Twice in the 1950â¤s tensions in the Taiwan Strait nearly expanded into nuclear conflict.