SYMPATHY FOR THE DEVIL By Kent Anderson Doubleday. 350 pp. $17.95

BY NOW it seems that more novels have been written about the Vietnam War than World War II. War has always been one of the great occasions for fiction, and fiction in general seeks to digest, condense and illuminate complex, ambiguous experiences. But Vietnam has generally resisted efforts at this kind of summary. Right after the American withdrawal a number of worthy books appeared, but the best of these were nonfiction: Michael Herr's Dispatches, Philip Caputo's A Rumor of War, and various compilations of first-person statements like Nam and Everything We Had that in effect said, "I was there, and believe it or not this is what happened to me." Most of the novels were pale by comparison.

The best Vietnam novels, the most considered and profound, are probably coming out now, just as our culture is getting ready to turn the whole long terrifying agony into popcorn and cotton candy -- dumb movies and dumber television serials. Lucius Shepard, who has tremendous gifts of style and vision, has written brilliantly about the war and promises to do much more -- and Kent Anderson, working with a narrower focus and a more realistic canvas than Shepard's, has outwritten just about everybody who preceded him in trying to make fictional sense out of the war.

Sympathy for the Devil is a first novel, clearly grounded in Anderson's own experiences, and it is not free of some typical first-novel excesses. Now and then there is some purple or over-earnest writing, and some of the devices meant to show that Hanson, the protagonist, is a thoughtful man as well as an extremely efficient killing machine do not work. (In the first 75 pages of the novel there are too many sentences like this one: "He killed the fly and recalled reading about monks in medieval Europe.") And the occasional digressions from Hanson's point of view are pointlessly distracting. But Sympathy for the Devil is powerful enough to make its own mistakes seem unimportant.

The novel centers on the experiences of a Special Forces sergeant known only as Hanson, who is part of a three-man Special Operations group working almost as a private army close to the Laotian border. Assisted by Montagnard tribesmen and Vietnamese ARVN soldiers, they routinely cross the border to locate the enemy and call in air strikes, snatch prisoners and gather intelligence, which will be attributed to other sources. Hanson and his partners, Quinn and Silver, detest the regular army almost as much as they do the Vietnamese with whom they are forced to work -- the author has placed us in the special world of the warrior, a very different being from the ordinary soldier, and part of his success is in his making us understand and appreciate the difference.

Warriors like Hanson, Quinn and Silver have been formed by temperament and training to a perfect adaptation to the conditions of their existence. They are existentially perfect soldiers, with no higher belief than in their own skill, alertness and brutality. America is insane and threatening, and the war has no higher goals than to permit them to exercise their skills. They know we cannot win, and have long ago left behind any belief they might have had in patriotic slogans. All they can trust is one another, their own bodies and the physical sensations that report reality to them. The magic of the Montagnard tribesmen, which amounts to an extreme sensitivity to the physical conditions of the landscape and its animals, makes much more sense than the self-serving and often foolish directives of the regular army. Their central emotions are anger and loyalty to the hard lessons of their experience.

THEY ARE uncomfortable people, and reading about them is unsettling. The brute makes an uneasy hero, and an elitist brute seems indefensible. Anderson begins to undermine our inevitable assumptions about these men by the solidity of his characterization -- they may be more like one another than they are like us, but they are very different individuals. Anderson has the ability to stay out of the way of his own characters and let them jump off the page toward us. You wouldn't want to meet these men on the street, much less in an alley or a bar, but they have enormous authenticity. They are wonderful fictional creations, so determined by the conditions of their existence that in any other occupation or location they would be psychotic; but their integrity is so great that our initial revulsion turns first to acceptance and then to respect.

Anderson appears to share many of his characters' assumptions, but his own honesty and talent are always qualifying them, making them understandable by revealing their sources. The assumptions can be as nasty as the feeling that strength is in itself moral, and as terrible as the mystic belief that warfare is necessary and redemptive. These beliefs are functional; they are to ideas what cartoons are to great paintings, and in the long run they are deeply destructive. Anderson knows that certain kinds of people can be seduced by these beliefs, and that at certain times they can seem absolute. "If you get too close to war," he says, speaking of the harsh training of a Green Beret, " . . . it will take you, muscle, brain and blood, into its heart, and you will never find joy anywhere else."

There's a world of sorrow and regret in that sentence and the novel moves unflinchingly through the various ferocious consequences of its equally ferocious assumptions. Anderson shows as how crazed Hanson is when his tour is up and he must deal with ordinary peacetime America. One of the most vivid sections of the novel shows its hero moving in a blur of drunken violence from one failure to another, and from outrage to panic. The panic is what makes Hanson sympathetic and Anderson's novel much more resonant than the sharply observed glorification of an untenable adolescent ideal it seems to be at first. The unknown, the unpredictable and the uncertain are full of terror, and when Hanson is brawling and boozing his way through California he can take pleasure only in natural phenomena. Ordinary human behavior maddens him with a rage which is half fear, half dread of his own capacity for violence. Of course he returns to I Corps, Quinn and Silver as soon as he can.

Before its cinematic and bitter conclusion, the novel wisely backtracks and shows how he got that way. Anderson leads us through both basic training and Special Forces camps at Hanson's side and lets us see an intelligent and competent young man gradually charmed, subtly flattered and seduced until he learns to admire what he calls "brute threat" -- if he were not more intelligent and competent than most of the people around him, he would never make it through the training. When we have seen what he has been through, we understand his loyalties and respect the genuine strength and manliness necessary to keep them in place.

Sympathy for the Devil is a wonderful achievement, written fluently and perceptively, and with the kind of unsparing intelligence that is rooted in careful observation -- the best kind, for a novelist. Kent Anderson, a Special Forces veteran, is not going to tell us any lies about the matters most important to him. He knows what has happened to him, and he can put it into fiction that wounds and stings. In several different ways, Sympathy for the Devil is a very brave book.

Peter Straub's novels include "Julia," "Ghost Story" and (with Stephen King) "The Talisman." His next book, "Koko," is about the Vietnam war.