To some extent, most documentaries rely upon the participation of their subjects. So how do you film a fairly negative documentary about a dangerous and powerful military dictator? Well, if you're Barbet Schroeder (Reversal Of Fortune, Kiss Of Death) and your subject is Idi Amin, the answer is very, very carefully. Made in 1974, when Amin was at the height of his power and notoriety, General Idi Amin Dada (newly reissued on video with several other early Schroeder works) is so reliant upon the participation and consent of its subject that its credits only half-jokingly bill it as a "self-portrait." On the surface, Dada is pretty uneventful, as Schroeder and his crew (including famed cinematographer Néstor Almendros, who makes Uganda look like a lush, almost unbelievably beautiful African utopia) follow Amin from one awkwardly staged tribute to another. But beneath the endless spectacle of singing, dancing Africans paying homage to their leader lies an undercurrent of fear and madness. It's a darkness that manifests itself in the belly-laugh Amin unleashes when asked if he really said that Hitler's mistake was that he didn't kill enough Jews, and in the tense, frightened body language of the people who have to deal with him face to face. In Schroeder's film, Amin emerges as a sort of alternate-universe Ronald Reagan, an eerily affable, perpetually smiling populist who's quick with a joke or folksy tale but seemingly oblivious to the consequences of his actions. The fact that Amin seems to genuinely believe what he's saying only makes him more unnerving. Dada never gets to the heart of Amin's power and popularity: It's possible to view his reign as a return of the repressed in an Africa scarred by colonialism (Amin received his military training in Western countries), but Schroeder never explores the point adequately, rendering Dada an interesting but disappointingly facile look at a man who was both a symptom and the source of unspeakable genocide.