JARHEAD

In movies, nothing is harder to define than tone, and the tone of Sam Mendes' Jarhead, based on Tony Swofford's Gulf War memoir, is so elusive that, hours after it ends, you might still not know what to make of it. In many ways, the movie is like a two-hour expansion of Full Metal Jacket's first 40 minutes, as the 20-year-old Swofford (Jake Gyllenhaal) and his fellow Marine recruits, pumped up to an almost insane degree, train for their mission in the unbearable desert heat and prepare for battle. In Mendes' film, however, there is no battle for his protagonists to respond to; the war ends while the Marines' bloodlust is still reaching a boil. The film is, in many ways, about the maddening banality of service, and it has resulted in an occasionally maddening movie, but its shifting tones and air of unpredictability make it impossible to shake off; at the finale, you might not know exactly what you've seen, but you certainly know you've seen something.