One of the more interesting things you can do with role-playing games is to fully explore alternate timelines in which history took a decidedly different turn. It is true that many novels do this as well, Harry Harrison's Stars & Stripes Forever series being one superlative example and the book Fatherland, by Robert Harris, being another, but what role-playing games allow you to do that novels cannot, is to explore the world on your own terms and, through your actions, experience the ramifications on a personal level.
One such game that has relatively disappeared from gaming history was Reichstar, by Creative Encounters.
I believe the reason the game is almost unknown is that it allows you to take pretty much any side in the conflict, including the Nazis or Imperial Japan, in a dystopian future run by the same. Many people find that idea to be too horrible to contemplate and feel to do so would forever mark you as a sympathizer for the Nazi cause.
I find this fascinating, because playing a bloodthirsty murder-hobo in D&D, an immensely depraved Sabbat vampire in V:tM (don't make me describe the horrors from that book), or an evil human sacrificing sorcerer in any number of games, never seems to phase those very same folks, but the idea of pretending to join up with the SS makes them feel all dirty inside.
I understand the argument that one is fantasy and the other is history, but is there really a difference when you are pretending to participate in the very same atrocities in your mind? Just because magic missiles don't exist and bullets do, does that make the act of killing any more acceptable? Is the raiding of a humanoid cavern to slay everything within and take their stuff based on the idea that they are 'sub-human' any different form the raids on Jewish homes to steal their hard-earned possessions and kill off their entire family?
Let me be very clear at this point: I do not take gaming nearly so seriously as all that. I really don't find it all that useful to navel gaze that deeply into what is, in essence, an adult game of make-believe. In fact, if I were to get even the slightest bit over-analytical on the subject, I'd say that playing a Nazi in the game could be helpful for exploring the historic forces and mindsets that led the Nationalist Socialist Party from a movement to recover German pride and independence, to a nationalist government driven to become a superpower, to one of the blackest, most vile political movements in (recent) recorded history.
At what point did it start to turn nominally sane people into monsters? What could generate so much fear and intimidation that an entire populace would rather turn a blind eye to the atrocities all around them rather than cry out for justice? And how much of that was actual fear or the selfish sense of superiority that we all know resides deep in the heart of every last person on this planet and led to an entire country basically saying ''the Jews deserve it' even though they personally would never lift a hand to harm anyone?
Learn from history or repeat it, as they say. See the slippery slope in action and learn to recognize its effect on humans in every culture in every era, including our own. And what better way to do that than to play a soldier in the Third Reich from the beginning, as an idealistic soldier in the SS with dreams of national unity and a proud Germany, to the end, when as a highly placed officer, your declaration of 'I was just following orders' does nothing to save you from the hangman's noose.
From a marketing perspective, however, games like Reichstar seem doomed from the outset because, even with all the disclaimers in large bold letters that proclaim the writers intent to educate not support, the whole idea of playing a Nazi is verboten. It's simply not PC in either use of that acronym: politically correct or player character.
Me personally, I thought Reichstar was a great game in concept and an interesting take on what life in the future would have been like if things had turned out differently in WWII. The mechanics were a bit all over the place, light in some areas and entirely too crunchy in others, but I'd say that if I could find the guys with the rights to the concept and get their permission, I'd be more than willing to remake it with a new system. Especially since it seems that, as we get further and further out from the events of WWII, as the last veterans of that war die out, people seem to throw about the term Nazi with way too much abandon and with too little concept of just how insulting that word really is. And all, ironically, while ignoring, or actually participating in, the attacks on religion, free speech, gun rights and personal liberty that were the historic markers of the growth of that very same movement over 70 years ago...