McNamara gained fame and acclaim originally as defense secretary for John F Kennedy and Lyndon Johnson and his notable accomplishments included engineering the war in Vietnam, and developing US defense doctrine for nuclear war that exist to this day. He was known for ruthlessly applying the cold, calculating precision of mathematical statistics to decision making.
Despite being the architect for America's invasion and conflict in South-West Asia, he later became a tireless advocate against war and America's militaristic and agressive foreign policies. In his later years, he became a tireless activist for nuclear disarmament and the ever present danger that nuclear weapons pose.
Ironically, McNamara later became an outspoken critic of his own war, saying,
"None of our allies supported us. Not Japan, not Germany, not Britain or France. If we can't persuade nations with comparable values of the merit of our cause, we'd better reexamine our reasoning."