They were interested in the territory of Manchuria in order to start their plan of expansionism. The Japanese used explosives to blow up a few feet of rail on the Japanese-built South Manchuria Railway on September 18th, 1931. In 1933, after the League of Nations condemned its actions in Manchuria, Japan withdrew from the league and followed an ultranationalist and pro-military policy. The Japanese army was far greater than China's, and the Chinese were out numbered.
Political instability in China made it easy for Japan to intervene in the territory. They preferred to fight a state with weak internal divisions. Sun Yat-sen led the Kuomintang in China. Mao Zedong led the Chinese Communist Party. China became the first nation to experience the horrors of World War II: brutal warfare against civilians and repressive occupation. During the invasion of China, Japanese forces used methods of warfare that led to mass death and suffering on a new, almost unimaginable, level. Guerrilla Warfare captured the loyalty of many Chinese peasants through their resistance to the Japanese and their new policies of land reform.
