The Things They Carried
Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
While O'Brien's tone in regards to the war jumps around from emotional to clinical to manipulative to epic, his tone in regards to storytelling and the truth is constant: he is absolutely familiar and close to his subject. He tells his stories with the complete confidence that he is right, that he understands his subject inside out. Even when he shifts reality from under our feet, we never doubt that he knows what he's doing, and that his manipulations serve a purpose.