During the 1930's Japan was looking to expand and gain new areas for resources. In 1931, Japan invaded Manchuria, against international law. After the League of Nations admonished Japan for this action, Japan simply leaves the League. In 1937, Japan launched a full invasion of China. During this war between China and Japan (Second Sino-Japanese War), Japanese soldiers committed many atrocities against the Chinese people, both military and civilian (Research: Rape of Nanjing). Approximately 15-20 million Chinese civilians and 4 million Chinese and Japanese military were killed in this conflict. In 1938, the Japanese turned their eyes toward the U.S.S.R. and the rich Siberian oil fields. The Japanese would test the Soviets by instigating conflict on the border region of the U.S.S.R and Manchuria. However, because of Japanese losses suffered during this action, Japan asked for a peace treaty between Japan the U.S.S.R., which will last until August 8th, 1945 when, after the dropping of the atomic bomb on Hiroshima, the U.S.S.R will declare war on Japan.