War & Pieces : THE LIVING AND THE DEAD: Robert McNamara and Five Lives of a Lost War.<i> By Paul Hendrickson (Alfred A. Knopf: $27.50, 427 pp.)</i> : OUR WAR: What We Did in Vietnam and What It Did to Us.<i> By David Harris (Times Books: $21, 195 pp.)</i>

These two books about the war in Vietnam could hardly be less alike and yet they steer us toward the same awful conclusion: Character is destiny, and grave flaws in character--not merely chance political missteps--doomed America to its misdoings in Southeast Asia. It was hubris that flung open the national trapdoor and lies and brutality that came careening out of the cellar.

“The Living and the Dead: Robert McNamara and Five Lives of a Lost War,” by journalist Paul Hendrickson, is a masterfully written, epic character study of Robert S. McNamara, the war’s brainy architect. “Our War: What We Did in Vietnam and What It Did to Us” is a j’accuse against the United States itself--a short, angry, reproachful memoir by David Harris, described nostalgically on the back cover as “the most famous draft resister of his generation.”

Hendrickson’s McNamara is an arrogant numbers-cruncher who “owned a significant conscience, which he was . . . continually willing to compromise.” That gives him much in common with Harris’ America, a people “who simply lost track of the difference between right and wrong.” Both had been storing up decades of bad karma, and Vietnam was the place where fate chose to collect its debt.

Of the two books, only Hendrickson’s is highly recommended. Cutting and yet compassionate, it is one of those rare works that combine the excavations of a historian with the insights of a poet. The prose races by effortlessly until it stops the reader in thought. By contrast, Harris’ book seems tired and all too familiar, like some anthem of protest that people lit candles to in 1970.

Much of “The Living and the Dead” is a conventional McNamara biography: the overstriding son of an up-from-the-shanty Irish shoe salesman, the Ford Motor Co. executive who gets teary-eyed over his Yeats, the astute secretary of defense whom Lyndon Johnson eventually pegs as a nut case and possible suicide.

But the book is also rich with Hendrickson’s meditations about this “tragically split man with a public mask,” a meshwork of good-hearted purpose and beady-eyed deceit. Infused with noblesse oblige, McNamara came to find the war futile but kept sending “platoons of the low-echelon into the high elephant grass.” As the bills piled up, he cooked the Pentagon books to hide the costs. His great need was to stay connected to power--and the result was a moral failure of nerve. “This above all, to thine own self be true,” Hendrickson writes. “He wasn’t. It was his greatest lie, really, trying to bifurcate, compartmentalize, who he was.”

McNamara, of course, last year issued a mea culpa of sorts. After three decades of Shakespearean torment, he published his own version of events (“In Retrospect: The Tragedy and Lessons of Vietnam,” Times Books) confessing to a series of “honest mistakes,” an excusable lapse in “judgment and capabilities,” but not any deeply rooted sins of “values and intentions.”

Hendrickson convincingly makes the opposite case. McNamara was an All-American boy who grew up with All-American ambition, selfishness and guile. His father may have been a strict, principled man, but young Bob learned to lie at his mother’s knee. She drove her brilliant son toward a success that willfully ignored the bearings of a good moral compass. Meanwhile, the author writes, “Huge conflicts are being stored up. Eventually, when he gets enmeshed in an event of unspeakable enormity, the interior cruelties will have no choice but to seek the light.”

By Hendrickson’s reconstruction of events, McNamara had lost belief in a military victory by the fall of 1965. In the Ia Drang valley, 455 U.S. soldiers had fought a ferocious battle against North Vietnamese regulars. By the numbers, the Americans won, with 234 dead against the enemy’s 2,000. But over a long war, even such a lopsided kill ratio would be unacceptable. As the secretary came to realize: “They would give a million dead over to their cause. And keep going.” The United States intended no such commitment.

McNamara kept his qualms from a largely trusting public--with fateful consequence. In late 1965, only 1,335 Americans had been killed and 6,131 wounded. By the time he resigned in 1967, casualty figures had hit 100,278. At war’s end, 58,000 Americans were dead--and perhaps 2 million Vietnamese.

Twice, in early 1966, the secretary seemed to want to come clean with his misgivings. In speeches out of character with his hard-boiled persona, he talked of war being an inferior means toward security and mused about man’s “near infinite capacity for folly.” Such sentiments stunned the Washington press corps. Regrettably, they seemed to stun McNamara as well. A year later, he said these remarks had been “childish,” born of frustration.

In his favor, some evidence shows that, behind the scenes, he occasionally pushed for the placing of limits on the war. But when rebuffed, the secretary was always accommodating. The author paraphrases the novelist Walker Percy: “[McNamara] was the kind of fellow who got all A’s and flunked life.”

Hendrickson trudged along a difficult path toward his conclusions. One of the best stylists in American newspapering, he has worked these past 19 years as a reporter at the Washington Post. In 1984, he had McNamara’s cooperation for a series. Unhappy with the product, McNamara became elusive when the profile turned into a longer project. On and off for 12 years, Hendrickson shaped and reshaped his book though his subject rarely spoke to him. He once slipped a note under McNamara’s hotel-room door and thought he “could hear him breathing.”

Surely, the gift of access would have made “The Living and the Dead” a different book. Yet the work may have turned out all the better for the constraint. It pushed Hendrickson toward an unusual storytelling structure, using his own ruminations to enrich the narrative and adding a supporting cast: five “ordinary” people touched by the secretary’s decisions.

Woven artfully through the text, these five portraits include an impulsive artist who tried to drown McNamara in 1972 and a Quaker pacifist who on Nov. 2, 1965, fatally set himself ablaze beneath the secretary’s Pentagon window. That morning, the Quaker had penned something about the interplay of faith and works that was sadly beyond McNamara’s grasp: “The most important thing in the world is that our faith becomes living experience and deed of life.”

In “Our War,” Harris also casts his eye at McNamara: “It is still hard for me to allow for the possibility that [his] slate will ever be clean. . . . Were I he, I suspect I would have blown my brains out years ago.”

At 50, Harris--who spent nearly two well-publicized years in federal prison while his then-wife, Joan Baez, dedicated songs to his courage--is not a forgiving sort. The war “still echoes in me,” he writes. He often paces in a 9-foot oval as if still locked up. When the Pledge of Allegiance is recited, he hesitates to join in. Beyond this, the war has defoliated his faith in the American people and their institutions:

“Having made lying an acceptable government function, our government is now overrun with liars. . . . Having failed to look our transgressions in the face, we have not been straight with each other since; having refused to live up to our own values, we are now increasingly without values at all.”

A gifted wordsmith, Harris can be quite eloquent when his prose is not hyperventilating. He grew up in Fresno and went to Stanford, becoming the student body president. Before Vietnam, he had believed in an America that did no wrong. “We were Sunday school graduates, Captain Kangaroo alumni, the Duke’s people, keepers of the White Hat and the eternal flame. We told ourselves that America always righted wrongs and never wronged rights.”

In his view, the war exposed the United States as the world’s great fraud, a country with people who took their civic lessons from the myths of Hollywood. Laid bare, America then shunned introspection in favor of the serviceable consensus that the war had been a “mistake.” This allowed Vietnam “to be mentioned in polite company with a reasonable chance of avoiding offense,” leaving the listener to choose whether our “mistake” had been one of villainy, geopolitical miscalculation or the failure to fully unleash the firepower.

Harris demands a national reckoning, a time to “stand outside our fears, revisit what we did so many years ago, and clear our souls of this perpetual shadow.” It’s hard to argue with this suggestion: Such mega-group therapy might turn experience into wisdom. Americans have learned to “stand tall again” without ever understanding how Vietnam laid us low.

But how does a nation perform such an implausible act of contrition? Harris does not say. A shame, too. After the war, the United States may have become more reticent to pick up its guns, but the same myths of chivalric purpose and moral superiority remain in place. Without an infusion of humility--and without more recognition of our bent toward expediency over principle--the next Vietnam awaits us, there like a troll under history’s long bridge.