Errol Morris's 2003 confessional interview with former US Secretary of Defense Robert McNamara. Won Best Documentary Oscar.
From Wikipedia
The Fog of War: Eleven Lessons from the Life of Robert S. McNamara is a 2003 American documentary film about the life and times of former U.S. Secretary of Defense Robert McNamara, illustrating his observations of the nature of modern warfare. It was directed by Errol Morris and features an original score by Philip Glass. The title derives from the military concept of the "fog of war", which refers to the difficulty of making decisions in the midst of conflict.