A lot of the criticism on rounds its alleged anti-semitism (american Jewish GIs act like Nazis) is based an failure to read the film's plot as well as it lessons in film history (the sequence on silver nitrate footage as explosive) and their integration. In terms of the plot, there are two conspiracies to kill Hitler and the audience. Both succeed. One includes the Jewish survivor of hte SS murder at the start of the film, who shoots the film's star (the German version of Sargeant York, according to the German solider turned star of the Nazi opposite film number, Pride of the Nation (a fictional film based Targets (dir. Peter Bogdanovich, 1968) based on the true story of the Texas Tower sniper and that ends in a drive in screening of a film starring Boris Karloff, who also stars in Targets) and then in turn is shot and killed by him though can't possibly have survived the three shots she gave him in the back, a sort of repetition of the brutal and surprisingly long scene in which the German film star (Diane Kruger) is strangled by Hans Landa, the SS villain. There's an overhead shot from the end of the climatic fight sequence from Taxi Driver here as well. As you can see, a lot of the film runs through late 60s into early 70s cinema--hence the spaghetti Western sound track themes). Nevertheless, the heroine's black lover gets her signal because it comes through her addition to the film. So her plot succeeds through film, through her film of the conspiracy, not by simple "action," and that action, of course, means using film footage as a bomb. And Hans Landa has left a bomb under Goebbels' seat which explodes before the bombs on the legs of the two GIs do. Moreover, it is Landa who lets the plot succeed. So there is a German-Jewish tension at the heart of the film's multiple plotting that cannot be resolved by equating of totally separating Nazis and Jewish civilian resistance fighters and Jewish GIs with Nazis. Moreover, the film again and again points to the centrality of film for the Nazis, much as it was central to the war effort in the U.S. Tarantino just literalizes the film as weapon metaphor, turning film itself into the explosive. Here Tarantino borrows a scene from Hitchcock's Sabotage--a film canister carried by Stevie explodes while he is on a London bus; the beginning of htis sequence appears in Tarentino's film). Just as Roosevelt had screenings of films like Olivier's Henry V and supporting Charlie Chaplin's The Great Dictator, so Hitler viewed various films, including, according to the film the Lives of he Bengal Lancers (in which Gary Cooper also stars, as he does in Sargeant York, as a kind of take action, engage the enemy NOW officer). The film's references to UFA, Leni Riefensthal,ad son all work to make the point that violence in film is not separate from violence outside film either for liberal democracies or fascist states; moreover, propaganda films made by the U.S. and by Germany aren't that different. Tarantino keeps drawing parallels and doubles, but mixing things up as well. The people in the two conspiracies don't know about each other and act independently, and Hans Landa only knows about one of them. The logic of action movies like the Eagle Has Landed or melodramas like Casablanca is entirely subverted by vertiginous references to historical events that were filmed and to films about history that refer to other films. So when Tarantino says that the civilian french couple who run the French cinema are like suicide bombers, it is naive to think he is drawing a simple comparison between real suicide bombers and cinematic ones. We already know, don't we, that television, the internet, and film are all central to Al-Queda? That they post videos of violence--that the Americans engage in their own psy-ops and always have? That the distinction between terrorist violence either by Israel (settlements, bulldozing, bomb dropping, gun fire) or by occupied Palestinians is not to be reduced to the same or the totally opposite? IG doesn't deny a difference between "real" history and film history but prevents any kind of interpretation in which one kind of history is read as the master of the other: the specters of victims haunting the present produced by traumas of the past can ever be exorcised or "re-membered" because the trauma itself already included always already spectral media (film, photography) which always route evidence through fantasy.
The mark of the Swastika at the end of IG is a remarking, a repetition of an earlier scene. In the first scene, we see a the end that the soldier has a swastika carved in his forehead. So we know the "masterpiece" at the end can be hidden as well. What marks Naziism is not is not an open wound or scar, but a hidden wound. Nazism did not know itself for what it is. Neither do Americans know their liberal democracy for what it is, Tarantino implies, as we are mired in Iraq and Afghanistan. We know but don't want to know about the extralegal violence the government (even under Obama) commits in the name of "state security."
Daniel Mendelsohn's reading of the film as anti-semitic: http://www.newsweek.com/id/212016/page/1 (My thanks to Jimmy Newlin for this link).