During world war 2 what happened between the communist and nationalist in China

There was civil war but in the context of a national war against Japan. Mao's revolutionary forces and Chiang Kai-shek's reactionary forces collaborated during this time to smash the Japanese invaders and secure national sovereignty. However, Chiang Kai-shek undermined this temporary alliance multiple times and also collaborated with the Japanese aggressors to undermine the communists. By 1947, the Chiang Kai-shek regime was "besieged by the whole people," and later overthrown in the Chinese Revolution of 1949.