One of the first actual conflicts of the Cold War took place in China. Following the withdrawal of Japanese troops after World War II, China was plunged into civil war, pitting Chinese Communists against Nationalists, who opposed Communism. The Soviets supported the Communists while the Americans supported the Nationalists. In 1949, the Communists were victorious, proclaiming the People's Republic of China. However, the Nationalists continued to rule the island of Taiwan off the coast. With American guarantees of protection for Taiwan, China did not make an attempt to take over the island. A major political change in East Asia in this period was Japan's becoming a tolerant, democratic society and an ally of the United States. In 1950, another conflict broke out in Asia, this time in Korea. The peninsula had been divided between a Communist North and non-Communist South in 1948 following the withdrawal of American and Soviet troops. In 1950, the North Koreans invaded South Korea, wanting to united the land under Communism. The UN condemned the action, and, because the Soviets were boycotting the organization at the time and therefore had no influence on it, the UN sent forces to liberate South Korea. Many nations sent troops, but most were from America. UN forces were able to liberate the South and even attempted to conquer the North. However, fearing the loss of North Korea, Communist China sent troops to the North. The U.S. did not retaliate against China, fearing war with the Soviet Union, so the war stalemated. In 1953 the two sides agreed to a return to the pre-war borders and a de-militarization of the border area.