Soviet–Japanese Neutrality Pact
In 1939, Japanese forces tried to push into the Soviet Far East from Manchuria. They were soundly defeated in the Battle of Khalkhin Gol by a mixed Soviet and Mongolian force led by Georgy Zhukov. This stopped Japanese expansion to the north, and Soviet aid to China ended as a result of the signing of the Soviet–Japanese Neutrality Pact at the beginning of its war against Germany.