The United States began supporting Taiwan in 1950 as part of the Cold War. Taiwan had broken from the newly created Communist Peoples' Republic of China. That recognition and ensuing relations between the U.S. and Taiwan complicated relations between the U.S. and China for 30 years. Even though the United States recognized Communist China in 1979, it remained committed to helping Taiwan defend itself, a fact that still angers China.
Taiwan is an island some 100 miles off the coast of China, bordered on the west by the Straits of Taiwan and on the east by the Philippine Sea. Its capital is Taipei, and it has a population of about 23 million. A majority of its people are Buddhists.
Taiwan has been a pawn in both Eastern and Western geopolitical strategy for centuries. Dutch imperialists claimed it in the 1600s. Spain later also claimed it. In the 18th and 19th Centuries, China claimed Taiwan and annexed it as a province.
In 1895, China went to war with Japan. Japan was itself embarking on an empire and in effort to emulate the great European empires, especially that of Great Britain. Japan, with its industrialized military, won the Sino-Japanese War and took possession of Taiwan.
Japan attempted to "Japanize" the people of the island. While it mandated that Taiwanese children learn Japanese, it also tried to modernize the island's economy.
World War II and the Chinese Civil War
In 1927, civil war broke out between communists under Mao Zedong -- who was trying to follow Russia's example in the creation of a communist state -- and nationalist Chinese (of the Kuomintang) under Chiang Kai-shek. The two sides fought until 1931 when Japan invaded -- then annexed -- the Chinese province of Manchuria. Forces under Mao and Chiang began an uneasy alliance as they worked together to fight Japan. This fighting was known as the Second Sino-Japanese War, but it was really the start of World War II in the Pacific.
While the United States refused to acknowledge the Japanese annexation of Manchuria in the Stimson Doctrine, it did little else. Mired in a spirit of isolationism, the United States did not enter the Pacific war until Japan bombed Pearl Harbor in December 1941.
Then it allied with the rival Chinese factions to fight Japan. President Franklin D. Roosevelt preferred Chiang's nationalists to Mao's communists (as did most Americans), but the U.S. attempted to work with both.
With the defeat of Japan in 1945, Taiwan reverted to Chinese control. With their common enemy removed, the communists and nationalists resumed their civil war. In 1949, with a communist victory eminent, 2 million nationalists fled to Taiwan. In October, Mao declared victory and instated the People's Republic of China (PRC) on the mainland. Two months later Chiang and the nationalists proclaimed the creation of the Republic of China (ROC) in Taiwan.
U.S. Support and the Cold War
The United States did not immediately recognize the government in Taiwan. When North Korea invaded South Korea in June 1950, touching off the Korean War, it forced the United States to apply its policy of containment to the Pacific Rim. Just as it sped troops to South Korea, the U.S. pledged to protect Taiwan from mainland Chinese aggression. President Harry Truman ordered the U.S. Seventh Fleet into the Taiwan Straits to maintain stability.
Straits of Taiwan Crises
In 1953, 1954, and 1958, the People's Liberation Army (PLA) -- Communist China's main army -- began attacking a string of islands in the Taiwan Straits which Taiwan claimed. The islands include Quemoy and Matsu. The PLA attacked with artillery fire and aerial bombardment, which at one point killed more than 700 nationalists defending one of the islands.
In response to the attacks, the U.S. Congress in 1954 approved the Formosa Resolution which authorized the American president (then Dwight D. Eisenhower) to use force to defend the islands. The Congressional measure was certainly in response to a growing belief in the "domino theory" in the Pacific -- that if one region fell to communism, so would others. The U.S. also began selling jet aircraft and artillery to Taiwan, a policy that remains in force.
Cold War anticommunism and American leadership of the West had secured Taiwan a seat in the United Nations rather than mainland China. However, as President Richard Nixon moved to normalize relations with China in 1971, much of the world followed suit. China soon replaced Taiwan at the U.N., and the U.S. recognized Beijing (then known as Peking), rather than Taipei as the center of its Chinese relations. The U.S. also recognized Beijing's "one-China" policy; essentially, the U.S. agreed that Taiwan was part of China.
Those changes, however, did not mean that the U.S. had shunned Taiwan. In a series of "joint communiques" with China, the U.S. explained its intention to maintain social, cultural, and defensive relations with Taiwan. The U.S. Congress codified that intent in the Taiwan Relations Act, which President Jimmy Carter signed in 1979. U.S. sales of arms to Taiwan have continued under that act, including a 2011 sale of retrofits to Taiwanese F-16 fighter jets.