How would WW2 end, and how would post WW2 look like without ALL major leaders from ww2? Your challenge is to end WW2 without FDR, Churchill, Stalin, Hitler, Mussolini, De Gaulle, Mao, Tojo, Kai-shek and Tito.
You can remove them however you like. Kill them, coup them, remove them, make them ill...starting in 1939 until the end of war.
Who would be their replacements? Would world today be better or worse place?