Both the White Paper on United States Relations with China released by the U.S. Department of State in 1949 and the letter from Secretary of State Dean Acheson to President Harry S. Truman admitted that, guided by its conceived global strategy and national interest considerations, the U.S. government gave full support to the Kuomintang, providing it with money, weapons and advisors to carry on the civil war and block the advance of the Chinese people's revolution. In his letter Acheson said: "The unfortunate but inescapable fact is that the ominous result of the civil war in China was beyond the control of the government of the United States. … Nothing that was left undone by this country has contributed to it. It was the product of internal Chinese forces, forces which this country tried to influence but could not."

At the time of the founding of the People's Republic of China, the then U.S. administration could have pulled itself from the quagmire of China's civil war. But it failed to do so. Instead, it adopted a policy of isolation and containment of New China. When the Korean War broke out, it tore up all international agreements about non-interference in China's internal affairs. In his statement on June 27, 1950 President Truman announced: "I have ordered the Seventh Fleet to prevent any attack on Formosa." Thus the Seventh Fleet invaded the Taiwan Straits and the U.S. 13th Air Force entered Taiwan and was stationed there. In December 1954 the United States concluded with the Taiwan authorities a so-called "Mutual Defense Treaty", placing China's Taiwan Province under U.S. "protection".

The erroneous policy of the U.S. government of continued interference in China's internal affairs led to the prolonged and intense confrontation in the Taiwan Straits area and henceforth the Taiwan question became a major dispute between China and the United States.