Why Did Hitler Invade Poland

Between August 10, 1939 And September 6, 1939, The Polish Partisans Killed Tens Of Thousands Of German Nationals In The Danzig Corridor.
This Was Carried Out By Polish And Polish Backed Jewish Partisans.
Hitler Had Already Done The 'Right Thing' By Protesting In Writing To The League Of Nations (Literally Dozens Of Times).