Why doesn't John McCain get it about Iraq?
It doesn't take a military genius to realize that the war can't be won because it was never winnable. All we're doing is stalling for time before the inevitable humiliating exit, as more money and more lives get poured down the drain every day.
The reason I'm puzzled is that McCain is a veteran of the Vietnam conflict, an unwinnable war if there ever was one. So why hasn't he learned the lesson of that war, as his fellow vets Chuck Hagel and Jim Webb have?
I think the answer is that we're all formed by our experiences, and McCain's Vietnam experience was very different from theirs.
They were infantry grunts slogging it out on the ground - Hagel as an Army squad leader and Webb as a Marine rifle platoon leader. Their war was up close and personal - and decidedly ambiguous.
It was a war of nuances. Some Vietnamese were friends; others were enemies.
And some who seemed to be friends were actually enemies, such as our nominal ally, the South Vietnamese Army, whose corruption did as much to lose the war as anything the Viet Cong ever did.
Others who seemed to be enemies turned out not to be, such as the innocent villagers who were massacred at My Lai.
For boys like Hagel and Webb, who went to Vietnam as gung-ho patriots, the war was a brutal disillusionment. They learned the hard way to see it in shades of gray.
In short, they grew up.
But McCain's war was black and white. As a Naval aviator, he lived on an aircraft carrier at sea. He'd take off, perform his mission and come back.
I doubt he ever met an actual Vietnamese person until the day he was shot down. And then the Vietnamese he met were monsters who showed him the worst side of human nature.
No wonder he saw - and still sees - that war as a contest between good and evil.
And his imprisonment had another effect: He missed out on what was happening back home during 5 1/2 crucial years, from 1967 to 1973.
He missed the Bobby Kennedy and Martin Luther King assassinations and the debacle that was the 1968 Democratic National Convention. He missed the Tet offensive, the Kent State killings, the Nixon "Southern strategy" and the rise of the women's movement.
All he knew is that when he got back he didn't recognize his country anymore. The American people, who were strong supporters of the war in 1967, had turned against it by 1973.
His faith in the righteousness of that war was what got him through the Hanoi Hilton. And now here were his countrymen ready to cut and run.
No wonder he concluded that the war could have been won if only we had been willing to stick it out a little longer. No wonder he felt betrayed.
And no wonder he's determined, come what may, to make sure we don't make the same "mistake" this time around.
But, of course, that war was doomed from the start; and so is this one, because both were based on fundamental misconceptions.
We went into Vietnam because we thought Ho Chi Minh was a stalking horse for Red China. Little did we know that the Vietnamese feared the Chinese far more than they feared us.
And we went into Iraq because we thought Saddam Hussein was a stalking horse for Al Qaeda. Little did we know that he and Osama would have cheerfully eviscerated each other if they could.
Of course, the truth was there for us to see in both wars. But we didn't see it, partly because we were lied to by our leaders.
But, it must be confessed, another reason was that we were too lazy to check out the facts for ourselves.
Today, the stakes are higher than they've ever been. Facing global warming, terrorism and a recession that threatens to slide into a depression, we need truth, not truthiness.
After 40 years, it's time to admit to ourselves that we lost the Vietnam War not because of some stab in the back, but because we were, as Gen. Omar Bradley put it, "fighting the wrong war in the wrong place against the wrong enemy."
And it's time to cut our losses and admit that this war is a loser, too.
Otherwise, our grandchildren will find themselves having the same conversation about another misbegotten war 40 years from now.