In his fantastic history of WW2 "Blood and Ruins: The Last Imperial War, 1931-1945" Richard Overy makes the same claim that WW2 really started in 1931 in large part because Japan and German (and Italy) had been denied colonial possessions (or had them taken away as penalty for losing WW1 in the case of Germany). But in the new conflict Hitler saw his colonial empire as nearby rather than overseas and expected to colonize the slavs.

I highly recommend the book!