Again, I'm not defending Nazi Germany. But if they were so obviously "Bad Guys," why did Japan, Italy, Finland, Hungary, Thailand, and more join their side?
(Speaking from what I've learned in recent history lessons & from family
Italy was a fascist dictatorship itself and agreed with Hitler's philosophy -- thus also being "bad guys" (not saying that the citizens were, of course, talking about the people actually in power).
As for Finland, I remember from my history lessons (I live and study in Finland, so we have had detailed courses on its history) that Finland had to join Germany at the point where Hitler and Stalin began being at odds. Since Finland wanted desperately to stay apart from Russia (which had ruled over it before), Germany was the only side it could choose if it wanted to fight to secure future freedom. Also remember the fact that the Soviet union was the one to attack Finland, not the other way around (Finland would have to be
insane to do that).
Hungary had similar reasons: due to being between the Axis powers and Soviet Russia, it needed to choose a side to protect it from the other one once Hitler started invading Russia. They chose Hitler, thinking that he'd win. They were, obviously, dreadfully mistaken and fell on the wrong side of the iron curtain in the end. (I've heard a lot about Hungary's history from my mother, who grew up there after World War II) So both Finland's and Hungary's main motivation to stand with Germany was that it would protect them from Russia. Japan and Thailand's motivations to join Germany are not clear to me. Perhaps somebody else could briefly explain those?
All this said, I dislike Stalin almost as much as Hitler, especially after hearing what life was like in Hungary during his reign and how Hungary still struggles because of how those times put it back.
Aaanyway, to be more on-topic: I cannot enjoy a historical novel if the people in it feel and sound completely modern. While I believe that we as humans have not changed at all during the past thousands of years (we share the same emotions, fears, desires, relationships, etc.), political views, society in general and beliefs certainly have, and I don't feel like a historical novel is being honest with me if it "shields" me from those differing views.
I don't mean that the book has to "approve" of the thoughts of the period. A character thinking one thing and that thing being supported as "right" by the book thematically are two completely different things. For example: A victorian gentleman, the MC, thinks that women are good for nothing. This is his opinion and I'm happy that he has it - after all, there were a lot of men during the period who believed that (though there must have been tons of exceptions, naturally).
This (IMO) is a plot supporting and even preaching his cause:
MC goes on heroic quests, female sidekicks try to help him out, they all fail miserably because of their feminine qualities. Author expects reader to laugh at the sillyness of women.
And this a plot which supports a modern POV, without changing his opinions:
MC goes on heroic quests and is occasionally helped out successfully be a female character. Though he may continue to believe women useless and make all kinds of excuses for these events, the reader sees that his (and/or society's) views are at odds with reality.
While this is not really a perfect example, I hope it helps me to illustrate my point: historical POVs are fine, but I like a book's themes to support the modern worldview.
edit// @wandering: Yes, that sums it up pretty well