"A second but simultaneous expansion of the Cold War occurred in East Asia, where on October 1, 1949—a week after Truman's announcement of the Soviet atomic bomb—a victorious Mao Zedong proclaimed the formation of the People's Republic of China. The celebration he staged in Beijing's Tiananmen Square marked the end of a civil war between the Chinese nationalists and the Chinese communists that had been going on for almost a quarter of a century. Mao's triumph surprised both Truman and Stalin: they had assumed that the nationalists, under their long-time leader Chiang Kai-shek, would continue to run China after World War II. Neither had anticipated the possibility that, within four years of Japan's surrender, the nationalists would be fleeing to the island of Taiwan, and the communists would be preparing to govern the most populous nation in the world."