400,000 men, 12,000 vehicles and 70,000 horses took part in operation Ichi-Go. The Japanese army included the very well trained Kwantung Army units and equipment from Manchukuo, North China and Japan. It was the largest land operation by the Japanese during the Second Sino-Japanese War. Many of the new American-trained Chinese units were fighting in Burma under General Joseph Stilwell using weapons leased from the United States. Chiang Kai-shek had agreed that Stilwell could manage the distribution of American arms. 