Answer:
The Molotov-Ribbentrop Pact, also known as the Nazi-Soviet Non-Aggression Pact, was a secret agreement signed between Nazi Germany and the Soviet Union on August 23, 1939. The key element of the pact was a non-aggression treaty, which meant that the two countries agreed not to attack each other and to remain neutral if one of them became involved in a war with a third country.
However, there were also secret provisions within the pact that outlined how the two countries would divide up Eastern Europe in the event of a war. The agreement included a secret protocol that divided the territories of Finland, Estonia, Latvia, Lithuania, Poland, and Romania into spheres of influence for Germany and the Soviet Union.
The secret protocol effectively gave Stalin's Soviet Union control over parts of Eastern Europe that it had long sought, while Hitler's Germany was given a free hand to launch its planned invasion of Poland without fear of Soviet intervention.
The Molotov-Ribbentrop Pact paved the way for the German invasion of Poland in September 1939, which marked the beginning of World War II. It also allowed the Soviet Union to annex parts of Finland and the Baltic States, and later become involved in the war against Germany after Hitler's surprise invasion of the Soviet Union in 1941. The pact was eventually broken by Hitler when he launched an invasion of the Soviet Union in June 1941.