The causes of WWII can be tracked back to WWI with the Treaty of Versailles. In the years leading up to WWII, Adolph Hitler had many geographical ambitions for Germany: once the Germans were put on a "restraint" with the threat of war by the English and French. This "restraint" didn't last long as Hitler eventually still proceeded into Poland in cooperation with the USSR, splitting the country of Poland into two, and the English & French keeping their word, the invasion of Poland plunged the world into war.
