Answer:
On August 23, 1939–shortly before World War II (1939-45) broke out in Europe–enemies Nazi Germany and the Soviet Union surprised the world by signing the German-Soviet Nonaggression Pact, in which the two countries agreed to take no military action against each other for the next 10 years.
For his part, Hitler wanted a nonaggression pact with the Soviet Union so that his armies could invade Poland virtually unopposed by a major power, after which Germany could deal with the forces of France and Britain in the west without having to simultaneously fight the Soviet Union on a second front in the east.