One of two important Chinese leaders during the years of Japanese aggression and occupation was Chiang Kai-shek, the leader of the Kuomintang and of the Republic of China. Chiang inherited the mantle of government from Sun Yat-sen and was in charge of the country's rebuilding for a time, but was soon faced with two enemies: Japan and the Communists. Under the slogan “first internal pacification, then external resistance,” Chiang led a significant armed force against the Communist forces, under Mao Tse-tung. This internal struggle cost China many men and much momentum in the early years of the Japanese invasion. However, by 1937, the two bitter rivals had agreed, at least on the surface, to put aside their differences and fight a common foe.
Years of bitter fighting between the Chinese and Japenese followed, with horrendous casualties on both sides, but especially Chinese forces. China lost 200,000 in the capture of Shanghai alone. Another 300,000 died in the Rape of Nanking. Chinese soldiers resisted Japanese aggression as much as possible. The country received a large amount of aid from the Allied powers, especially the United States, which sent the famous Flying Tigers to beef up China's air defenses. China also provided landing space to those pilots who were lucky enough to escape after dropping bombs on Japan in James Doo-little's famous raid.
Chiang emerged as the national leader and a friend of the Allied powers, who made him one of the “big four” and invited him to the historic Cairo Conference in 1943. He remained the nominal leader of the country after the Japanese surrender but soon lost his position in the Communist Revolution. Chiang fled China for Formosa (Taiwan) in 1950 and ruled there until his death in 1975.