This study attempts to analyze systematically the rationale, evolution, and consequences of Chiang Kai-shek's "unity before resistance" doctrine, which was the basis of Nanking's appeasement policy. The author argues that there were a number of independent variables that influenced Nanking's attitude toward Japan: 1) the internal disintegration of China; 2) factional conflicts within the Kuomintang;3) ineffective administration; 4) the vicissitudes of nationalism; 5) the material backwardness of China; and 6) international mediation. All of these factors were interrelated. The intervening variables were Chiang Kai-shek's personality, his patterns of political behavior, his way of ruling, and his perception of internal and external crises. By adopting the temporary appeasement policy toward Japan, Chiang hoped to gain enough time to consolidate China and his supreme leadership. But Chiang’s appeasement policy in fact engaged his government in two races - one with Japanese aggression and the other with domestic opposition.