I watched Inglourious Basterds recently, and somewhat unwillingly. Being one of Tarantino's works, it didn't have much to do with reality, but the frightening thing about the movie was that someone might take it at face value as an example of heroism in combat. I'd like to think that it was intended as parody, but that doesn't seem likely.
The movie was rife with gratuitous violence, of course, but that's par for the course these days. What struck me was that there wasn't a single major character with any moral character in the film. I found myself rooting for the fire at the end, hoping no one would make it out alive.
I suspect that the little girl at the beginning of the show, orphaned by nazis, was meant to be sympathetic, but when she grew into a hateful young woman, consumed with revenge, I lost all interest. What she did might have ended Tarantino's fictional WWII, but that's not what she had in mind. She tortured and brutalized her own countrymen and sacrificed her best friend's life for vengeance, with any good that might come from it a distant second.
As for the "basterds" themselves, I doubt that many people consider that they were terrorists, in every sense of the word. In fact, they had so much in common with the ISIL asshats we're fighting now, it's scary. Both used the same level of violence and horror to achieve their ends. Tarantino's "heroes" had all been savaged by the nazis, but then again, our wars in the middle-east have left a generation of Iraqi orphans with legitimate reasons to hate us as well. Really, the only difference between the two groups beyond their size and technology is that America won WWII and the middle-east never wins against the overwhelming advantage enjoyed by the west.
Someone will probably point out that the "basterds" never raped anyone (onscreen, at least). However they did torture a wounded female resistance fighter. Subtle distinction. Let's face it, the movie had more psychopaths than the average serial killer convention (kudos if you got the Sandman reference).
Apparently (I can't find the actual article), Christopher Hitchens described the movie as "sitting in the dark having a great pot of warm piss emptied very slowly over your head." That sounds about right.