What german moves and diplomatic failures led to the start of world war ii in europe? what role did the soviet union play in the road to war?

Germany began to build up its military when Adolf Hitler came to power.  After that he began invading one European country after another.  Russia had signed a non-aggression pact with Germany. France and Great Britain were still recovering from the previous war that they signed a treaty of appeasement with the Germans who later took territory from Czechoslovakia.  When Germany invaded Poland with Russia’s help, it started The Second World War. 

where is the map at?