BOOK REVIEW / NOVEL : A Fine Line Between Criminals and Heroes in the Army : THE OLD ARMY GAME <i> by George Garrett</i> ; Southern Methodist University Press $22.50, 344 pages

I was in the Army once, long enough to know that I wasn’t a soldier. I was a civilian in uniform. For my own good and for the Army’s as well, I got out when my two years were over.

Such blatant incompatibility called for divorce--though I’ve lived long enough since to realize that this wasn’t necessarily due, as I thought at the time, to any fault of the Army’s or any virtue of mine.

Fortunately, some of the Army’s inmates are soldiers. George Garrett may have been one. At any rate, he could recognize good soldiers when he saw them, and recognize, too, that they may or may not be what a civilian would call good people.

In this collection of nine stories and a short novel--”Which Ones Are the Enemy?” first published in 1961--Garrett’s observations of Army life in the Korean War era hold true for the Vietnam War, when I served, and for the present day. Nothing changes less, from time to time and country to country, than the military.

The novel owes a debt, Garrett acknowledges, to James Jones’ epic of the pre-World War II Army, “From Here to Eternity.” But it owes just as much to Hemingway’s World War I novel “A Farewell to Arms,” from the stoic cynicism and the hard, clean style down to the deathbed scene at the end, with Garrett’s Pvt. John Riche standing in for Lt. Henry and an Italian bar girl for Hemingway’s nurse.

Riche, even to himself, is a “born loser.” He’s a little man who wants to be big, a hustler, a sociopath. He knows where trouble lies but can’t stay out of it. The novel begins on his release from a military prison and ends with him back behind bars, victim of the bureaucracy he hates.

Why does he stay in the Army at all? Because he’s a decorated hero of Korea; he can play the good soldier when it suits his purposes and he belongs to the brotherhood of those who can be good when the shooting starts.

After Korea and the stockade, Riche finds himself in the “Nth Field,” a ragtag U.S. artillery unit stationed during a period of Cold War tension along the Yugoslav border near Trieste.

Some of the soldiers there are good people; others make the Dirty Dozen look like choirboys. But enough are Riche’s kind so that he feels a rare contentment, a willingness to reclaim his place in the brotherhood and ask for nothing more.

Then trouble comes--from a familiar source and an unexpected one. Riche wins a bundle at poker and rediscovers that “just the idea of (money) and all you can do with it . . . makes me shiver and sweat.” He meets Angela, the bar girl, who rejects him unless he can set her up in an apartment. So Riche returns to what got him jailed before: dealing in the black market.

Riche’s motive for living with Angela is to punish her for disdaining little men, as well as to assert the sexual advantage enjoyed by occupying troops in any war-torn country. Neither expects to fall in love. Riche, in particular, seems incapable of it.

Garrett, best known for three novels set in Elizabethan times, is an expert at first-person narration. Most of the interest in “Which Ones Are the Enemy?” comes from the clash between different sides of Riche’s character, between what he tells us directly and what we figure out about him.

How can a criminal also be a hero? This is what drives Riche’s nemesis, Lt. Costello, the battery executive officer, crazy. How can a man so venal and selfish speak as an authority on what’s phony and what’s not? How can the love that heals Riche’s lifelong malaise also deprive him of the only other love and security he has known?

The short stories in “The Old Army Game” are of similarly high quality. Some borrow the novel’s characters and setting. Two are shrewdly stylized “cartoons.” All deal with the “invisible world” of suffering that lies just beyond the boundaries of Army regulations and civilian naivete.

We might ask why these works faded into obscurity. Such is the volume of published literature that no explanation is needed. The most likely, though, is bad timing. “Which Ones Are the Enemy?” appeared just before a period in American history when the military virtues fell into disrepute, when “good soldier” seemed an oxymoron. That period, for better or worse, has ended. Today’s readers may be more willing to see Army life through Garrett’s unsparing but respectful eyes.