Robert McNamara’s actions during the Vietnam War were wrong, terribly wrong.

Such was the assessment of a knowledgable critic: McNamara himself.

The Secretary of Defense during the administrations of Presidents John Kennedy and Lyndon Johnson, who has died at age 93, was in his day portrayed as the most brilliant technocrat in an era when brilliant technocrats were worshipped by the media and political elites. Unfortunately, his own tragic trajectory confirmed that the best and the brightest were fallible — in the extreme.

A Ford Motors “whiz kid” who brought his management skills to Kennedy’s Camelot and stayed around long enough to watch the dream crumble under Johnson. When he arrived at the Department of Defense, McNamara admitted that his knowledge of military matters was scant. But he was confident enough — arguably “arrogant enough” — to believe he could master the Pentagon with a mumbo-jumbo of management platitudes — announcing his intention to apply an “active role” management philosophy that involved “providing aggressive leadership questioning, suggesting alternatives, proposing objectives and stimulating progress.”

In other words, McNamara winged it.

Badly.

McNamara peddled the fantasy that something happened in the Gulf of Tonkin that justified giving him a blank check for a massive war in southeast Asia. And McNamara cashed the check, flooding Vietnam with U.S. troops — 535,000 by 1968 — and bringing tens of thousands of those young soldiers home dead or horribly wounded. The Secretary of Defense had tried to fight a war with statistical theories and anti-communist, Domino-theory fantasies. And the project failed.

McNamara recognized this by late 1967 and made some effort to alter U.S. strategies. But it was too late, for him and for Lyndon Johnson’s presidency, which crashed and burned in the Mekong Delta.

Johnson sent McNamara off to run the World Bank — where the master manager did considerable harm as a pioneering proponent of neo-colonial development schemes that the managerial class continues to inflict upon the poorest people on the planet — and that was that.

Except for one thing.

McNamara felt guilty about his management of the Vietnam imbroglio.

His best-selling 1995 reflection on the personal and global nightmare that the war in southeast Asia became, In Retrospect was read by many Americans as an apology. While it may have fallen short of what was required, McNamara did admit that he and is compatriots fouled up — horribly.

Specifically, McNamara wrote: “We of the Kennedy and Johnson administrations who participated in the decisions on Vietnam acted according to what we thought were the principles and traditions of this nation. We made our decisions in light of those values. Yet we were wrong, terribly wrong.”

Noam Chomsky offered a tough but fair review of the McNamara memoir: “The one interesting aspect of the book is how little he understood about what was going on or understands today. He doesn’t even understand what he was involved in. I assume he’s telling the truth. The book has a kind of ring of honesty about it. What it reads like is an extremely narrow technocrat, a small-time engineer who was given a particular job to do and just tried to do that job efficiently, didn’t understand anything that was going on, including what he himself was doing.”

Almost a decade later, in the documentary Fog of War McNamara would admit to a many more failures. Most importantly, he expanded on his earlier acknowledgement that, “We do not have the God-given right to shape every nation in our image or as we choose.”

McNamara applied that standard to the Bush-Cheney administration’s mad misadventure in Iraq, saying that: “(If) we can’t persuade other nations with comparable values and comparable interests of the merit of our course, we should reconsider the course, and very likely change it. And if we’d followed that rule, we wouldn’t have been in Vietnam, because there wasn’t one single major ally, not France or Britain or Germany or Japan, that agreed with our course or stood beside us there. And we wouldn’t be in Iraq.”

Does getting Iraq right offer absolution for getting Vietnam wrong?

Do admissions of errors ease the burden of those errors?

McNamara lived long enough to raise these questions.

History will answer them, perhaps unkindly.

But we ought not underestimate the significance of McNamara’s admission that he was “wrong, terribly wrong.”

He displayed a measure of self-awareness, and self-doubt, that is healthy — and all too rare among major figures in the military-industrial complex about which Dwight Eisenhower warned about on the eve of Robert McNamara’s confirmation as Secretary of Defense, and of which McNamara was an embodiment.

Consider the prospect that Dick Cheney or Donald Rumsfeld will ever admit to having been “wrong, terribly wrong” about Iraq and you begin to get a measure of the meaning of the former Defense Secretary’s late-in-life admissions. It can easily be argued that he was insufficiently repentant, and insufficiently insightful. But there was something refreshing about the fact that McNamara felt compelled to try and explain himself.