Boot camp, a shadow world where the U.S. Marine Corps transforms bumbling civilians into combat-ready Marines. It's a demanding professional school, but they don't use the Socratic method, there are no ivy-covered halls, and that's not John Houseman standing at the lectern. The curriculum includes coping with physical privation and psychological stress. The professor is the drill instructor, the DI, and his challenge is a formidable one: teaching green recruits to cope with hunger, fatigue, fear.

Staff Sgt. Roger Markey, career Marine, decorated Vietnam veteran, DI at the Corps' San Diego boot camp (next stop: Vietnam), has a pragmatic, survivalist solution to that challenge: You can't learn to handle duress from a book or a lecture; you learn it by living it. Markey pushes his platoon of recruits hard -- very hard -- and his methods don't always follow the training manual. He is everywhere, a perfectionist relentlessly pushing and prodding his charges to physical and psychological extremes. Until one of them, a well-meaning, inept recruit named Loren Collins, who has failed to measure up to Markey's demanding regimen, is beaten to death with his own rifle.

The logical suspect, the only suspect: Roger Markey, who is charged with murder. The invisible, unindicted co-conspirator on trial with him is the unsanctioned, uncompromising training regimen he advocates.

Marine Capt. Mike Taggart, a short-timer rotated from Vietnam to a desk slot as defense counsel at the San Diego recruit depot, intends to use his remaining time in the Corps to shore up his crumbling marriage and polish up his re'sume' for a smooth reentry into a civilian law firm. He finds himself instead defending Markey. Taggart thinks Markey may be innocent, a belief shared by few in light of eyewitness testimony that Markey hit Collins with a rifle shortly before Collins died.

Markey and Taggart, the "lifer" and short-timer paired in a high-stakes, uphill first novel. Although it is set in the Vietnam era, this is not just a story about Vietnam. The book focuses instead on two little-understood aspects of military life -- the training and discipline of recruits and the military justice system. Britton, a former Marine officer, Vietnam veteran and defense counsel of DIs in Marine court-martial proceedings, provides incisive insights into both.

The core of the novel centers on Markey's handling of the platoon in the nine weeks before Collins' death and on Taggart's preparation for and defense of Markey at the court-martial. It is skillfully structured, presented in convincing detail, and it makes for good reading.

Britton also succeeds in capturing vignettes of stateside military life in the waning days of Vietnam: the boozy camaraderie of officers club happy hours; the strains military families face as they traverse the nation; Taggart's outburst at civilian neighbors who avoided the war with Selective Service insurance, the diapered deferment -- all have the ring of firsthand observation and experience.

When Britton shifts events from the training center and the courtroom to the world outside, the book runs into difficulties. Some characters -- Pvt. Collins' antiwar activist sister, in particular -- are sketchily defined. Taggart's romantic involvement with Veronica Rasmussen, a television reporter dispatched to San Diego to cover the Markey court-martial, is predictable. She arrives equating the word "Marine" with "the image of some bullet-headed thug running through a brick wall just to get to the other side." He seeks to show her the realities that belie the stereotypes. They walk on the beach a lot, and recite Rod McKuen to each other. In these settings, Taggart is one Marine who should never have hit the beach.

Fortunately, Britton's recounting of the court-martial offsets these shortcomings. The trial unfolds at a staccato pace, and takes a number of convincing unexpected turns. There are surprise witnesses, a squabble over the admissibility of a potentially damning blot on Markey's otherwise impeccable service record, and the introduction of some revealing, previously undisclosed letters from Pvt. Collins to his family written in the weeks prior to his death. Britton has a knack for explaining the significance of each new development and he keeps the outcome, which is neither predictable nor contrived, in doubt throughout.

On balance, this is a first novel with much to commend it.