To young scribe, ‘Mac’ was mentor, keen observer of US affairs

He was the vilified architect of the Vietnam War that had so shaped my parents’ generation. He was the symbol of all the promise - and hubris - of the “whiz kids’’ of the Kennedy years, with his wire-rimmed glasses and slicked-backed hair peering out from those black-and-white photos. And he was the man who helped bring us back from the brink during the 1962 Cuban missile crisis, when my mother was kept home from school because of fear of a nuclear holocaust.

But to my surprise after I arrived in Washington 15 years ago with virtually no experience, I found him a willing, if sometimes blunt, tutor in international affairs, one who was generous with his time even for someone like me.

In a number of face-to-face discussions and many more lengthy phone conversations that grew warmer and more jocular over the years, his appetite for analyzing some of the nation’s most pressing national security challenges was never satisfied. He also never lost his desire for information, often pumping me on what I was hearing from officials still on the inside.

At first he requested that nothing he said be quoted - he was already too much of a lightning rod, he would say - but after a while he agreed that I could use his name if I thought his perspective on a particular issue, such as nuclear weapons or the pitfalls of managing the Pentagon bureaucracy, was relevant to a story I was writing.

He didn’t look anything like the buttoned-down former businessman that I expected. That was partly due to his age - he was already near 80 when I first called him - but also because he had acquired the disheveled, absent-minded professor look about him, his shirt untucked, his thinning hair unkempt.

A few times I ran into him near his office, a stack of papers tucked under his arm, as he was shuffling past the White House. Moving at a pretty good clip, his stooped, rumpled frame would wind through the throngs of tourists who paid him no mind. I would think: If only these people knew the imprint this man had on their national identity.

We had lengthy conversations about nuclear arms and what he saw as the folly of the continued reliance by the United States and Russia after the Cold War on a similar defense structure, with thousands of missiles pointed at each other, that he said was a recipe for an accidental nuclear war and only emboldened other countries to seek nuclear arms.

He was less forthcoming about Vietnam, which he knew was his undoing in the public eye, so I rarely pressed him on it. I soon learned that Vietnam was only the best-known chapter of his career, anyway.

But he did sometimes open up, as he did when I called him for a story during the 2004 presidential race about John F. Kerry’s assertions that atrocities were committed by US forces in Southeast Asia. On that score, he was the direct former Ford Motor Co. chief I had read about in high school, expressing surprise that people were still debating the issue.

“There were atrocities, without any question,’’ he told me. “We had photographs of officers shooting innocent Vietnamese.’’

He was animated when talking about the challenges facing the United States immediately after the Sept. 11, 2001, attacks. He voiced deep concern about sending large numbers of conventional military forces to Afghanistan for any extended time, citing the rout of the mighty Soviet Army there during the 1980s. As on other topics, he spoke from experience on that, too, having spent time in Afghanistan as head of the World Bank.

Sometimes he just relished the opportunity to tell old stories, such as how he became secretary of defense. President John F. Kennedy, he recalled, first offered him the job of secretary of the treasury, but McNamara said he didn’t think he had enough experience.

So then the president-elect asked him about the Pentagon job. When McNamara again demurred, based on his lack of qualifications, Kennedy got frustrated. “Come on, Bob, there’s no school for presidents, either.’’ That’s how it began, he said with a chuckle.

He also loved to tell the yarn about when he had to close either the Boston or Brooklyn Navy Yard in a Pentagon downsizing effort in the mid-1960s. He called in the senators from those states, Edward M. Kennedy of Massachusetts and Robert F. Kennedy of New York, and told the brothers to work it out. The younger Kennedy, who had been in the Senate two years longer, pulled rank, and the Brooklyn Navy Yard was no more.

The self-interest was certainly detectable when McNamara’s gruff voice would be on the other end of the phone. After all, I was a reporter and McNamara was selling books, seeking consulting fees, and looking to burnish his statesmanship credentials to help balance out his war-stained reputation.

But I saw another side: a man whose lifelong obsession was searching for the right solutions.

When I heard he died yesterday morning at the age of 93, I couldn’t help but think it was fitting that at the moment he died, a US president was in Moscow seeking historic cuts in nuclear arms. Mac would have had a lot to say about that.

Bryan Bender can be reached at bender@globe.com.