The 'Towards the Superman' subsection of "The Intrepid and the Cruel in WWII" chapter in GURPS WWII: Weird War II goes into more detail.
A problem not touched in the book was the power level of many Golden Age comic book heroes. While "Mystery Men" (like Batman or Hour Man) inactivity was explainable to readers the more powerful ones (Like Superman, Alan Scott Green Lantern, Wonder Woman) were more problematic.
For example, the 1940 comic "How Superman Would End the War" had Superman fly in to German and the USSR grab both Hitler and Stalin and drop them off in front of the the League of Nations (Strangely the comic makes no mention of Japan).
Eventually DC had to come up with a reason why with all these superheroes didn't just go in and demolish the Axis powers resulted in the Spear of Destiny and Holy Grail which didn't really make sense. Why would the Spectre be affected and why would a Christian holy item in the hands of Japan do anything to keep out any Super heroes. In fact, in "The 11th Hour" episode of the Fleischer Superman cartoons cartoons Superman actively sabotages Japanese war production in Yokohama, Japan so even that explanation didn't make sense.
References[]
- GURPS WWII: Weird War II pg 105-108
- GURPS WWII pg 165