Robert McNamara, defense secretary under Kennedy and Johnson and one of the architects of the Vietnam War, sits for an extended interview with Errol Morris and works through eleven lessons drawn from his own career. He talks about firebombing Japanese cities under Curtis LeMay before the atomic bombs fell, about the Cuban Missile Crisis, and about the decisions that escalated Vietnam into a war that killed millions. Morris intercuts the interview with declassified White House tapes, archival combat footage, and Philip Glass's score, letting McNamara's own justifications and doubts sit side by side without a narrator smoothing them over. McNamara is candid about miscalculation and the limits of rationality in war, but he stops short of apology, and the film lets that gap stand. The result is less a biography than an old man auditing his own conscience on camera, arguing with himself about whether reason can actually control violence once a war begins.