Occupation official turned historian Richard B. Finn notes, "World War II was the first major conflict in history in which the victors carried out trials and punishment of thousands of persons in the defeated nations for 'crimes against peace' and 'crimes against humanity,' two new and broadly defined categories of international crime." For most people, this calls to mind the trials of Nazi war criminals at Nuremberg. But an equally difficult, fascinating, and controversial set of trials occurred in Tokyo, under the watchful eye of Supreme Commander Douglas MacArthur.