When "The Man Who Lost the War," the first novel by the pseudonymous W. T. Tyler, was published in 1980, reviewers, hungry for an American who could rival the masterly British writers of political intrigue, pulled out all the stops. "Better than any recent Graham Greene," one called Tyler, while others hailed him as equal to the genre's reigning deity, John le Carre'. But, though the clamor of praise was loud and the curiosity about his true identity great, it wasn't enough to cause Samuel J. Hamrick, then a veteran foreign service officer of almost 20 years, to step forward and take a bow.

Two years and two books -- "The Ants of God" and the current "Rogue's March" -- later, Hamrick, 53, is now an ex-foreign service officer, retired to a farm in Fauquier County, Va. So he has allowed his publisher to reveal his name, slipped in as discreetly as possible on the inside back flap of the newest book's dust jacket.Hamrick explains W. T. Tyler this way: "It comes from Wat Tyler leader of a 14th-century peasants' revolt in England . I was feeling rebellious when my publisher asked me to pick a name."

The man who calls himself W. T. Tyler has what is usually described as considerable presence. He looks both patrician and masculine, like a Yalie with an interesting past. The horn-rimmed glasses that he takes out of his shirt pocket--but doesn't put on -- are held together at the temple with a Band-Aid.

Wearing a striped cotton shirt that he rolls up above his elbows, Hamrick projects a virile elegance: a highly polished rough diamond. It isn't hard to imagine him as a hero of someone else's novels -- but not his own. Though he strongly disagrees with this characterization, his heroes seem a bit burnt-out. There is nothing charred about Sam Hamrick.

He has, without question, been where the action is, in countries such as Lebanon, Zaire, Ethiopia, Somalia, where the politics are not decided by TV ad campaigns. Not surprisingly, one word most of his friends and acquaintances eventually use to capture him is "loner." Yet Hamrick's family, his four grown children and wife of 30 years, has always been with him.

Another love is books. For him, "Thomas Pynchon is the strongest American writer today," while William Faulkner, Garcia Marquez and Louis-Ferdinand Ce'line are other favorites. Despite this, he professes "ambivalence" about his own novel writing. "It's a vulgar form, compared to poetry and drama," he says.

But that statement, in the face of his obvious passion for fiction, comes across as more mischievous or provocative than heartfelt. What about John le Carre'? Hamrick is emphatic: "What he writes bears no relation to British intelligence, you can take my word for it. He's created a unique, private world, like Conrad's Africa. He's really a social observer, of a closed, class-ridden society."

Upon leaving the State Department in early 1980, Hamrick intended eventually to come out into the open. In his opinion, trying to maintain a separate identity is "hypocritical, and someone who does this is a dilettante."

But publicity is something he's been trained to avoid, and publishing, with its demands for a commercial attitude, is not an enterprise for which Hamrick has much respect. (He'd trade the entire industry, he jests, for 10 foreign service officers, or reform it with them if he could.) Still, the need to express himself and what he was observing, outside of the endless cables and memorandums, was, he thinks, what caused the creative writer in him to burst forth.

"Diplomatic reporting is so one-dimensional; the human element is wiped out. You have to be interested in answers, not motivation. The intuitive factor, too, is completely lacking." He goes on, "What is superfluous to the diplomatic life becomes the basis for what you write about."

Former State Department colleagues agree that Sam Hamrick displayed in the course of a career, spent largely in Africa toward the close, enough intuition and insight into the "human element" to be considered "unique."

Here's what two former superiors have to say: Richard Moose, formerly assistant secretary of state for African affairs, says, "The business of writing memos in the State Department practically deserves a study in itself. You start off with the known biases of the various bureaucratic players, and all the while you're crafting it so there will be one, inescapable conclusion . . . There is simply no occasion to write the deeper, more insightful kinds of things Sam had to say."

James Bishop, currently deputy assistant secretary for African affairs, put it this way: "We have to write in a standard format professionally. The secretary of state's not interested in how someone feels on a particular day." Both agree that Hamrick's official prose was impeccable, often subtly different than anyone else's, but still--official.

Moose remembers that he, and everyone else at State, didn't know that the thoughtful, but not exactly mild-mannered, Hamrick was wearing a novelist's flying cape beneath his pinstripes. "When he told me he was resigning I did everything I could to keep him there. But he said, 'I've put up with this bull---- as long as I can.' "

It was then Moose was let in on the secret. And, later, Bishop: "As evidenced, he's a profound person. But even some of us who knew him well were surprised by the depth and sophistication" in his books.

Says John Loughran, former U.S. ambassador to Somalia in the mid-'70s, under whom Hamrick served in Mogadishu: "Sam is on a quest and this [the writing] is part of the growth."

Richard Petree, another career foreign service officer, now retired and president of the United States-Japan Foundation, was Hamrick's superior in the early '70s in Addis Ababa. One unusual memory sticks in Petree's mind, and it's one that reinforces the other perceptions of Hamrick's sensitivity, the something more beneath the surface of the hard-working diplomat.

"He bought a lot of African art, but the quality was different than most of us tourists were getting. He understood Africa, saw more, than the rest of us did," Petree says.

"The Ants of God" and "Rogue's March" are both set there. The former takes place along the Sudanese-Ethiopian border, where an American pilot is running guns; the latter unfolds against the Congo upheavals. "The Man Who Lost the War," however, was primarily set in Berlin, East and West. Its editor, Juris Jurjevics of The Dial Press, echoes Petree when he says that the "sensational foreign rights" sales (editions in nine countries) resulted from Hamrick's having gotten "under the skin of Europeans in a way that surprised them."

But before he was W.T. Tyler, before he was Samuel Hamrick of the foreign service, Hamrick was a young man from Louisville who wasn't sure what he wanted to do with his life. Putting aside the expectations of the local society (debutante balls, exclusive clubs to which he belonged), his first adult-sized act of rebellion was to ignore the Ivy League and head, as the '50s began, for the University of New Mexico, where he wanted to study under the anthropologist Franz Boas. Then, drafted, he spent two years in army counterintelligence ("I won't talk about that"), followed by stints back home in tobacco warehouses and later in southern Alabama as a construction worker.

Finishing college at the University of Louisville, Hamrick began graduate work at Vanderbilt but wound up taking the foreign service exam. Entering in 1960, his first post was in Beirut. Montreal and Newfoundland were next, then Africa. He speaks French, Italian, German, Russian and Lingala, the Bantu dialect of the western Congo. Typically, though, not speaking is a virtue he holds paramount. "The job of a diplomat -- and most American ambassadors don't understand this -- is to listen."

Hamrick's lips curl with scorn as he addresses himself to the Reagan administration, which, in a change of pace, is the subject of the novel he's now working on. He describes the book as "full of one-liners and pratfalls," the implication being that he doesn't have to look past the headlines for inspiration. After that, a book on foreign relations, probably dealing with the Horn of Africa, while another future project is a history of the U.S. Patent Office, an institution that's long fascinated him.

Hamrick has always taken his ideas from life. One man he befriended along the way was an Eastern Bloc opposite number -- "I'll call him a Czech" -- who became the starting point for the character Strekov, a Russian official who's inexplicably leaking secrets to the West in "The Man Who Lost the War." Years later, a woman Hamrick listened to, sitting on the veranda of a mission station in the Kasai region of the Congo, inspired the plot of "The Ants of God," which includes a relationship somewhat reminiscent of Bogart and Hepburn's in "The African Queen." "She'd seen a plane without a light, violating the Angolan border at night." There was nothing more she could tell him. But it was enough.