McNamara’s whole life was an illustration of the limits of American liberalism, the way in which a man who tought of himself as a decent person could convince himself to support and plan atrocities against foreign peoples in the name of national interest. Educated in the best liberal traditions at Berkeley, he spent World War II helping Curtis LeMay lay waste to Japan more efficiently, to which the atom bombing of Hiroshima and Nagasaki was just a coda. He then went from warfare to business using the same methods to help Ford become profitable again, became president of Ford, the first outside of the Ford family before joining the Kennedy administration as the Secretary of Defence, as which he was largely responsible for shaping the American strategy in Vietnam and the escalation of the war there with all that entails. When he left (or was kicked out) in 1968, he then joined the World Bank until his retirement.
As the 2003 documentary Fog of War makes clear, McNamara throughout his career was driven by his own moral convictions, doing what he thought was right for America. He genuinely believed in the ideals on which America was supposedly founded, was never driven by greed or vanity as much as the idea of doing your duty for your country, of noblesse oblige. He was honest enough to understand when he was wrong and why he was wrong when it came to the War on Vietnam and to admit to it, even if the doubts he had about the whole war only surfaced once he was out of office. But in all this he was limited by his ideological background, more so because he never realised it was there. He believed he was a rational, pragmatic man, that the things he believed in where just the facts of life, that what was best for America was what was best for the world, that paternalistic capitalism was the best system in the world, that communism was threatening world peace and needed to be stopped and that what happened in Vietnam was the US defending itself. The limits of his vision meant that he could only recognise this last error, but not the errors in his own world view that lead to it.
He wasn’t a bad man, a genuine monster like the ones found in the Nixon, Reagan and Bush administrations, who only paid lip service to America’s ideals but only truly believed in American power. But his humanity wasn’t enough. He still served the system.