Second Sino-Japanese War

What happened

Japan invaded China (July 1937) seeking resources and regional dominance. Japanese forces swept through coastal regions and major cities despite stiff Chinese resistance under Chiang Kai-shek and Mao. The Battle of Shanghai (1937) killed 250,000+; the Massacre of Nanjing (1937-1938) saw Japanese troops murder 200,000-300,000 civilians and soldiers. Japan occupied major cities but China's vast interior resisted. Chinese Communists and Nationalists fought Japan separately, then allied loosely. By 1945, Japan controlled railways and cities but 80% of territory and 95% of population remained beyond effective Japanese control. Estimates of Chinese deaths: 15-20 million through combat, starvation, and massacre.

Why it mattered

The Second Sino-Japanese War demonstrated Japan's imperial ambitions and brutal occupation policies. The Nanjing Massacre became an atrocity emblematic of Japanese militarism—disputed by Japanese nationalists, commemorated by Chinese. The war merged into WWII (Pearl Harbor 1941), with China fighting from 1937-1945 while Europe's major war began 1939. China's resistance proved Japan could not easily conquer Asia's largest nation. The war's devastation of rural China contributed to Communist victory in the Chinese Civil War (1949). Japanese war crimes in China remain unresolved historically and politically.