I am determined to be gallant and butch and a glory to the marines."" So writes homosexual Kurt Strom--a super-handsome Southerner whose letters home from Vietnam, 1966-67, make up this long, occasionally amusing, mostly wearying mÃ‰lange of Nam-medic horrors and gay-sex confessions. Ex-baseball player Kurt varies his tone and explicitness depending on who's getting the letter--his hip grandma (""Mom""), his raunchy cousin Chloe, an ex-lover, a straight friend--but throughout he's relentlessly flip, bitchy, and snobbish. From a visit home to warring mother and grandma (the book's best sequence), he moves on to his enlistment; his mangy buddies and one-night stands at Camp Lejeune; and his assignment to the 1st Medical Battalion in Chu Lai--where he works on Kitchen Patrol or Surgical Intensive Care (""Did you know that stomach contents are dark green and look like liquid spinach?"") and begins his panting seductions of every presentable male in sight. It's when Kurt is then sent to an infantry company, however (""Yes, dear heart, I am in the jungle. Aba daba daba""), that the gore and lust really start churning: leeches, colostomy bags, and deaths on patrol alternate with mutual masturbation, etc. And after a trip home for his mother's funeral, Kurt is back with the 1st Med Battalion, now in Da Nang--where his conquests include helpless ones (he manipulates delirious and unconscious patients into sexual contact) as well as twosomes and threesomes in Saigon with married pilots Steve and Don. (Kurt prefers straight men: ""Besides the excitement of fucking virgin ass, they've never heard the rumors that it's supposed to hurt."") Finally, however, he winds up in Bou Bou Phu as a medic for both the military and Vietnamese civilians--and his credo (""Fuck and forget or fuck and fuck again and again"") leads to some ugly triangles there. . . . First-novelist Nelson shows some talent for mincingly comic petulance and raunchiness--and many of the Vietnam-life details (the medical grue, the G.I. mindlessness) register authentically. But the black-comic balance between graphic sex-farce and war carnage never even comes close to working (descents into porno-doggerel--""I've had hand-to-hand combat with his prick/ It's long and spongy, succulent and thick""--don't help); and there's virtually no impact in the random mutilations and deaths. An intermittently lively, would-be comedy/tragedy, then, which ultimately reeks of self-indulgence and cheapens its basic material.