 Complete the following phrase:  World War II is generally considered to have begun on 1 September 1939, when Nazi Germany, under Adolf Hitler, invaded Poland. The United Kingdom and France subsequently declared war on Germany on the 3rd. Under the MolotovRibbentrop Pact of August 1939, Germany and the Soviet Union had partitioned Poland and marked out their spheres of influence across Finland, Romania and the Baltic states. From late 1939 to early 1941, in a series of campaigns and 