As the object of his pursuit, character actor Cliff Curtis (you'll recognize the face from Three Kings and Training Day) commits the sin of being absolutely generic. It's not entirely his fault: Screenwriters David and Peter Griffiths apparently decided a strong villain wasn't necessary and limited Curtis' character, cleverly named El Lobo, to scant screen time. We know he's evil because he makes one of his men swallow a live poisonous snake, and because he hangs pictures of Lenin on the walls.
Schwarzenegger appears to be taking acting lessons these days; if you can ignore the intrusively familiar accent, he has recently turned in some of his most credible work, a trend that unfortunately correlates with a significant decline in the quality of the scripts he chooses. The oft-insufferable John Leguizamo, as comic relief, isn't terrible either, though his role amounts to little more than addressing Arnold as "jolly green giant" and "sour kraut." John Turturro steals a scene or two by impersonating Harry Dean Stanton, but the major talent gap of the film lies with Francesca Neri (Hannibal) as El Lobo's inexplicable Caucasian supermodel-of-a-wife. Neri seems to think repeatedly batting her eyelids counts as acting.
Portraying the most believable character in the film is Crash's Elias Koteas, as a CIA agent making unsavory deals to try to protect the United States--even if it means screwing over innocent people in the process. He's the one element of the movie that feels absolutely timely, embodying Dick Cheney's philosophy of recruiting unpleasant individuals who'll get the job done. Standing in stark contrast to that is the fictional White House's response to the first major act of foreign terror on American soil: "We must fight the temptation to make hasty policy decisions we might regret." Insert your own punch line here.