From what two general directions did allied forces move in on japan

Before 1942, Chinese military force fought against Japan in Southeastern Asia with British soldiers. But within the borders of China, only Chinese military force, nobody else. Until 1945, when the war was heading to the end, former Soviet Union troops participated in wiping Japanese from the northeast of China. We should not forget that a big number of American volunteer pilots joined the efforts of Chinese government in protecting the flight routes between Chongqing, temporary capital of China, and international supplies. Most of them were cargo flight pilots. Chinese people called them "Flying Tiger".