Ridley Scott's harrowing replay of a 1993 Somalian debacle for U.S. troops is pure cinema in action. In nearly two hours of relentless warfare (think of Saving Private Ryan without the slow bits), it shows how a director can marshal images and sounds, biography and geography, to create emotion pictures. With Gladiator, Hannibal and now this ultimate war movie, Ridley's on a roll.