When the Pacific War began, Japan controlled all China’s industrial centres and major ports. Jiang Jieshi was in a poor situation, under threat from Japanese airpower and with dwindling sources of supply. Soviet aid stopped after 1940 as Stalin wished to avoid antagonising the Japanese, and wanted to marshal his resources for possible conflict with Germany. The Burma Road was sporadically closed under Japanese pressure. However, Japan did not have the military force to conquer the rest of China, or even achieve a decisive victory. Both sides were pre-occupied with maintaining authority in their spheres. Jiang was continually faced with the need to exert his authority over his own forces, many of which owed at least partial allegiance to a local warlord. Then there were the Communists (CCP) based in Fushih. After the Sian agreement there was an uneasy truce between the Kuomintang (KMT) and CCP, to focus their attention on the Japanese. Communist forces were under Jiang’s nominal overall command, though in practice they fought separate wars.