He obviously likes Marines, but he's seen the issues from several angles, as a combat officer in the field, as a political appointee, and as a journalist. If you think of the Marines as average guys with the tough but honorable job of defending the country, you might like it. If you don't like politicians and bureaucrats, you're on safe ground. Bruce Greenwood is the national security advisor and head conspirator against our Marines. Ben Kingsley is the ambassador that Childers rescued.
Greenwood is particularly slick, playing the villain with a smirk but without much nuance.
Kingsley has a minor role. He makes a fateful decision in a scene with Greenwood, but we don't know the character well enough to know how believable it is. Guy Pearce is the third key conspirator, the prosecuting attorney. Pearce plays Major Biggs as an aggressive and arrogant young hotshot, obviously much smarter than Col. Hodges, the opposing lawyer, but nowhere nearly as experienced. If Tommy Lee Jones and Samuel L. Jackson are well-cast as marines, they are perfectly cast as guys who know that marines are, first and foremost, not lawyers or bureaucrats, but warriors.