 With skillful organization and propaganda, the Communists increased party membership from 100,000 in 1937 to 1.2 million by 1945.Mao also began to execute his plan to establish a new China by rapidly moving his forces from Yan'an and elsewhere to Manchuria.This opportunity was available to the Communists because although Nationalist representatives were not invited to Yalta, they had been consulted and had agreed to the Soviet invasion of Manchuria in the belief that the Soviet Union would cooperate only with the Nationalist government after the war.