This effective, well-paced antimilitary thriller has more conflicting flashbacks than you can shake a stick at. On New Year’s Eve 1999 a sadistic drill sergeant (Samuel L. Jackson) at a U.S. army base near the Panama Canal leads a squad of trainees on jungle maneuvers during a hurricane, and only two men survive (Giovanni Ribisi and Brian Van Holt). The irritated captain (Connie Nielsen) calls in a cantankerous ex-army ranger (John Travolta, terrific) to help question the survivors about what happened. Director John McTiernan does a swell job with James Vanderbilt’s sneaky script in keeping us guessing. 98 min. (JR)