During Japanese War and World War II the Communist Part spent nearly a decade in Yan’an, developing many important aspects of Maoism. From this base of power, Mao would launch the last phase of a revolution that swept Chiang from power and established the People’s Republic.

Mao used the war years to develop ideology that would govern the party’s direction for decades. He put forward the system of self-criticism and made famous speeches on the political role of the arts and the media.

Mao was joined by an American delegation during World War II (to liaise between the Communists and Nationalists) and initial perceptions of Mao by the Americans were quite positive, at least by comparison to Chiang. Mao’s government was not as corrupt as the Nationalists, and didn’t suffer from Chiang Kai-shek’s timidity during the war.