sentences:  By this time Sun had become convinced that the only hope for a unified China lay in a military conquest from his base in the south, followed by a period of political tutelage that would culminate in the transition to democracy.In order to hasten the conquest of China, he began a policy of active cooperation with the Communist Party of China (CPC).Sun and the Soviet Union's Adolph Joffe signed the Sun-Joffe Manifesto in January 1923.