Robert McNamara, Lyndon Johnson’s icy-veined, cold-visaged and rigidly intellectual point man for a war that sent thousands upon thousands of people (most of them young) to their utterly pointless deaths, has died at the ripe old age of 93.

Long after the horror of Vietnam was over, McNamara would concede, in remarks that were like salt in the still festering wounds of the loved ones of those who had died, that he had been “wrong, terribly wrong” about the war. I felt nothing but utter contempt for his concession.

I remember getting my draft notice in the mid-1960s as Johnson’s military buildup for the war was in full swing. I’m not sure what I expected. Probably that the other recruits would be a tough bunch, that they would all look like John Wayne. I was staggered on the first day of basic training at Fort Dix, N.J., to be part of a motley gathering of mostly scared and skinny kids who looked like the guys I’d gone to high school with. Who looked, basically, pun intended, like me.

That’s who was shipped off to Vietnam in droves — youngsters 18, 19, 20 and 21. Many, of course, would die there, and many others would come back forever scarred.

Johnson and McNamara should have been looking out for those kids, who knew nothing about geopolitics, or why they were being turned into trained killers who, we were told, could cold-bloodedly smoke the enemy — “Good shot!” — and then kick back and smoke a Marlboro. Many would end up weeping on the battlefield, crying for their moms with their dying breaths. Or trembling uncontrollably as they watched buddies, covered in filth, bleed to death before their eyes — sometimes in their arms.

I was lucky. The Army sent me to Korea, which was no walk in the park, but it wasn’t Vietnam. I served in the intelligence office of an engineer battalion. But no one could truly escape the war. I would get letters from home that would make my heart sink, letters telling me that this buddy had been killed, that that buddy had been killed, that a kid that I had played football or softball with — or had gone to the rifle range with — had been killed.

For what?

McNamara didn’t know. My sister’s boyfriend got shot. A very close friend of mine came back from Vietnam so messed up psychologically that he killed his wife and himself.

The hardest lesson for people in power to accept is that wars are unrelentingly hideous enterprises, that they butcher people without mercy and therefore should be undertaken only when absolutely necessary.

Kids who are sent off to war are forced to grow up too fast. They soon learn what real toughness is, and it has nothing to do with lousy bureaucrats and armchair warriors sacrificing the lives of the young for political considerations and hollow, flag-waving, risk-free expressions of patriotic fervor.

McNamara, it turns out, had realized early on that Vietnam was a lost cause, but he kept that crucial information close to his chest, like a gambler trying to bluff his way through a bad hand, as America continued to send tens of thousands to their doom. How in God’s name did he ever look at himself in a mirror?

Lessons learned from Vietnam? None.

As The Times’s Tim Weiner pointed out in McNamara’s obituary, Congress authorized the war after President Johnson contended that American warships had been attacked by North Vietnamese patrol boats in the Gulf of Tonkin in August 1964. The attack never happened. As Mr. Weiner wrote, “The American ships had been firing at their own sonar shadows on a dark night.”

But McNamara, relying on intelligence reports, told Johnson that evidence of the attack was ironclad. Does this remind anyone of the “slam dunk” evidence of Saddam Hussein’s weapons of mass destruction?

More than 58,000 Americans died in Vietnam and some 2 million to 3 million Vietnamese. More than 4,000 Americans have died in Iraq, and no one knows how many hundreds of thousands of Iraqis. Even as I was writing this, reports were coming in of seven more American G.I.’s killed in Afghanistan — a war that made sense in the immediate aftermath of the Sept. 11 attacks, but makes very little sense now.

None of these wars had clearly articulated goals or endgames. None were pursued with the kind of intensity and sense of common purpose and shared sacrifice that marked World War II. Wars are now mostly background noise, distant events overshadowed by celebrity deaths and the antics of Sarah Palin, Mark Sanford and the like.

The obscenity of war is lost on most Americans, and that drains the death of Robert McNamara of any real significance.