The Invasion of Poland in 1939 marked the beginning of World War II, as Germany and the Soviet Union coordinated to divide and occupy Poland. This act of aggression violated international treaties and set the stage for further Nazi expansion in Europe.

pharaphrase this

The commencement of World War II occurred with the invasion of Poland in 1939, when Germany and the Soviet Union collaborated to divide and take control of Poland. This aggressive action disregarded international agreements and paved the way for subsequent Nazi territorial expansions in Europe.