The beginning of the Second World War was preceded by a series of diplomatic activities by Nazi Germany in order to assimilate territories, which the Germans thought were unfairly seized by the Versailles Agreement, or historically belonging to them. Also, Hitler wanted to be secured by signing a non-aggression pact with the Soviet Union, in August 1939. The Germans tried to correct the "injustice" and exercise their right to "living space" which, they consider, historically belonged to them. One of the key areas on which they were "deposed" are the parts of Poland. Thus began an offensive to Poland on September 1, 1939, and that is the beginning of World War II, since France and Britain declared war on Germany on September 3, 1939.
The answer is Poland.
