This was one of Polanski's great ones. I think I like him best when he's at his most political - that is, when he allows his normal psychosexual concerns take on sociopolitical overtones. Here it's sort of the reverse: he's taken a play that seems to have been mostly sociopolitical in its concerns and brought out its psychosexual overtones. This old review by Owen Gleiberman runs them down well: "Death and the Maiden is a true Polanski movie now, a sadomasochistic love story that locks torturer and victim together in a chillingly intimate spiritual embrace."
Where I differ from Gleiberman's take is in seeing the political dimensions of the story being given equal importance. Maybe this is easier for an American to see in 2010 than in 1995, at least an American who's had the scales fall from his eyes with regard to his fellow-citizens' willingness to torture and condone torture. The subject of the movie is torture, and how societies deal with it: that comes through loud and clear.
That's why for me, the husband is the most interesting character. Sigourney Weaver's Paulina is a marvel, "stalk(ing) through the rubble like a battered Amazon queen exacting her revenge," in Charles Taylor's phrase (the other review I linked to above). And Ben Kingsley as the suspect Dr. Miranda is amazing, his final confession being one of the most five minutes of speaking you'll ever see, sketching for us how an ordinary man, with the ordinary load of ingrained lusts and anger, can, in the right circumstances, act like a monster, and how he can explain it himself afterward, and to what degree he can forgive himself.
But the figure of Paulina's husband is the real fulcrum of the drama, as we see him struggle to understand the situation. He's supposed to be a dedicated democrat, a crusader for truth and justice for the victims of the old regime, not to mention that he's Paulina's loving husband. But when her actions, her accusation of the doctor, put him on the spot, we suddenly see how as a man, with a normal load of reflexive misogyny; as a husband, with a normal load of grievance; as a lawyer, with a normal distrust of uncorroborated testimony; as a political figure, with a normal sympathy for authority; as a citizen, with a normal unwillingness to see his kind neighbor as a villain; as a peaceful man, with a normal hesitation to use violence; as all these things and more, he's utterly unequipped to give Paulina's story the credence it deserves, and respond with the action it demands. He hesitates at every key moment. And if he hesitates now, how can we expect the truth and reconciliation commission to work?