Shift of strategic direction of United States following the Korean War
I have been wondering why Taiwan wasn't returned to China as promised in the Cairo Declaration. It turned out that outbreak of Korean War was the turning point for America's shift of international order for East Asia.
After losing the Chinese Civil War to the Communists, the Chinese Nationalists fled to Taiwan. The United States, having lost confidence in the Chinese Nationalist regime, pursued a policy of not intervening in civil wars. The Chinese Communists were prepared to cross the Taiwan Strait to completely defeat the Chinese Nationalists and unify all of China.
The outbreak of Korean War in June 1950 prompted the United States under President Harry S. Truman to dispatch Seventh Fleet to the Taiwan Strait so as to prevent hostilities between opposing factions of China, while war was ongoing at the Korean Peninsula. Notwithstanding that Chiang Kai Shek was spared from Communist attack, the dispatch of Seventh Fleet threatened strategic interests of the nascent People’s Republic of China.
The shift in US strategic direction for East Asia is reflected in the change of territorial clause in the Treaty of Peace with Japan. In a draft released on 8 May 1950, it was stipulated that Japan renounce Taiwan without naming a recipient country.
The People’s Republic of China, through Premier Zhou Enlai, filed a protest at the United Nations on 24 August 1950, claiming that the United States was invading the Chinese territory of Taiwan with the Seventh Fleet. This motion was tabled in the Security Council on 29 September 1950. All members of the Security Council, except USSR and India, voted against the motion. The Chinese government-in-exile, by voting against the motion, denied that Taiwan is a sovereign Chinese territory. The vote also spared the question of Chinese seat to be resolved immediately, against a backdrop of containing Communism.
Resolution of the Security Council was a bitter defeat for the Chinese Communist Party. Having no formidable navy, their nascent regime was at the mercy of United States.
The Communists, up to 1947 still supported Taiwan independence; changed their direction after 1950 to opposing Taiwan independence and claiming Taiwan as Chinese territory.
People’s Republic of China intervened in the Korean War on 25 October 1950, pushing United Nations solders back to the 38th parallel North, cementing the division of Korea lasting to this day.
Taiwan, originally planned to be returned to China, was not returned to China in the Treaty of Peace with Japan. Similarly Kuril and South Sakhalin were not de jure returned to the USSR. The peace treaty provides a basis to argue for Taiwanese independence in the future, at the same time providing a room for future unification with China. The treaty reaffirmed the United States as the "principal occupying power" over former Japanese territories. By law, Taiwan is currently under friendly occupation of the United States.
This is politics: As situation changes, promises made earlier will not hold.