John Wayne. Patriotic, fearless, selfless. The image is woven deeply into the entire American presence in the Vietnam War. John Wayne. The mythic, tough-talking man of action. The rock-hard spirit of the United States Marines. Not afraid to punch out an enemy soldier's heart, yet sensitive enough to be gentle with an orphan of the war.

John Wayne haunts Gustav Hasford's first novel, "The Short-Timers." The main character, James Davis -- known as Joker -- lapses into a John Wayne imitation at the first sign of tension. "The Green Berets" is showing in the Da Nang military movie house when Joker and a sidekick stop in for a matinee. Hasford drops the Duke of Hollywood's name periodically throughout the book -- as a noun or an adjective. As in: "Crazy did a John Wayne. He finally went berserk." Or, "You got to write about our John Wayne lieutenant."

This is not the first book that illustrates the John Wayne myth's hold over the American fighting man in Vietnam. Two powerful nonfiction works by former Marines -- Philip Caputo's "A Rumor of War" and Ron Kovic's "Born on the Fourth of July" -- and James Webb's novel "Fields of Fire" reveal that many a U.S. soldier was killed, maimed or suffered severe psychological damage acting out a John Wayne fantasy in the Vietnam jungle.

Hasford's sarcastic Joker avoids being a casualty. He sticks to John Wayne imitations. Joker is the book's central figure, but he has no heroic qualities. Joker is a half-step above his fellow Marine grunts, having been a combat correspondent before getting assigned to a rifle company. But he's as bitter, cynical, foul-mouthed and violence-prone as his Marine buddies, Cowboy, Animal Mother and Crazy Earl.

Just like his buddies, Joker has a short-timer's calendar on his flak jacket (hence the book's title.) Each day he crosses off another date.

Gradually, Joker's short-timer's calendar winds down to zero. There is a vivid description of Hue in the aftermath of the 1968 Tet offensive and a grimly realistic portrayal of Marines under siege at Khesanh. Hasford also includes the obligatory scenes of search-and-destroy jungle patrols, unexpected fire fights, and random episodes of gratuitous violence, including maiming, fragging and raping. All this has been presented in much better literary and dramatic terms elsewhere. Michael Herr's "Dispatches" and Webb's and Caputo's works are three books that come readily to mind.

Hasford's battle descriptions are the best "The Short-Timers" has to offer. The plot itself is thin. The author follows Joker from boot camp, through a few combat correspondent activities, to a final harrowing adventure on night patrol. No character offers any particularly startling insights into the nature of the fighting in Vietnam. Mostly the grunts just grouse about lifers, quarrel with each other constantly and try to stay alive.

Hasford's book is quite short, just 154 pages, barely long enough to qualify as a novel. Joker is the most fully developed character, but he is neither strong enough to make him a hero nor interesting enough to make him an anti-hero.

Still Hasford knows his subject. He served as a Marine combat correspondent with the First Marine Division in Vietnam. But simply having been in Vietnam is not enough to write a first-rate novel.