Why is Hitler the only boogeyman? There were a shitload of other people who believed in the same ideas that he had to have done what happened. Sure a lot were scared to die and just did what they were told, but initially Hitler had to have a lot of support or else his regime would never have gotten off the ground.
The power axis made him out to be the only gangster.
Read about pre WW1 relations between Germany and England, France and America especially how the press portrayed the German nation and its people.
A pretty clear picture starts to develop.
Germany, plus its people, have always been seen as the main obstacle to world governance.