A loose thread which has run through most of Tarantino's films is the idea that anyone who puts on a mask, or a disguise, or a costume, or just pretends to be someone else... is doomed. The Reservoir Dogs couldn't spot the traitor in their midst because they'd obliterated their own identities, and The Bride's attempt to be Mrs. Tommy Plimpton ended in disaster. With Inglourious Basterds, Tarantino has finally delivered a definitive exploration of this theme. The more horrible it gets, the more wonderful it gets - and it gets pretty damn horrible.
The plot: Aldo Raine is off to Nazi-occupied France to make a Western. He's cast a dozen angry Jewish soldiers as Apache indians, and the entire Wehrmacht as marauding cowboys. And in the best war movie tradition, he's keeping absolute demarkation between the goodies and the baddies. Trouble is, not everyone on Aldo's own side can play their own parts perfectly either. Phoney German and Italian accents might fool the home audience, but won't get past astute critics like Gestapo Major Dieter Hellstrom and SS Colonel Hans Landa. By the time Aldo Raine and Josef Goebbels have finished making their respective propaganda fantasies, war has become so theatrical, and cinema so violent, that there's no distinction between a combat ambush and a movie premiere.
Some reviewers condemned this movie on moral grounds, namely that it transforms Jews into mass-murderers and Nazis into victims - which it does, but you're not meant to like that transformation; you're meant to be horrified. Inglourious Basterds has very little concern for historical reality, but plenty to say about the art that portrays it. It's the type of masterwork which I can only call "thematically saturated" - everything reflects the theme in some way; there's barely a single gesture which is superfluous or gratuitous. The attention to detail is meticulous. Tarantino really takes his time ratcheting up suspense over very polite, genteel conversations, giving much greater impact to the intermittent bursts of extremely bloody violence.
This is postmodern filmmaking at its very best - composed entirely from loving recreations of the worst glorifying excesses of gung-ho war movies, but knitting them all into a macabre ironic comedy of art, violence, masquerade, and collapsing identity.