Little did Aaron Sorkin suspect, when he wrote the lefty drama "A Few Good Men," that the only thing anyone would ever remember about it was Jack Nicholson’s Col. Jessep speech, which Sorkin accidentally made more convincing than any liberal argument he ever offered: "Son, we live in a world that has walls and those walls have to be guarded by men with guns. You want me on that wall — you need me on that wall. My existence, while grotesque and incomprehensible to you, saves lives." Col. Jessup, shake hands with your 21st-century equivalent: Robert Downey Jr.’s Tony Stark....