The Company They Keep : SIRO <i> By David Ignatius (Farrar, Straus & Giroux: $17.95; 465 pp.) </i>

When it comes to the international machinations of governments and their sometimes out-of-control representatives, David Ignatius, a former reporter for the Wall Street Journal and current foreign editor at the Washington Post, knows what he’s talking about.

“Siro,” his second novel of espionage (after “Agents of Innocence”), is a thoroughly engaging and taut thriller, pitting rogue agents of the CIA against the KGB as they stir the pot of dissent in the Soviet Union. But in another, deeper sense, it is the story of the spy agency against itself, with the remnants of the adventurous old guard tracking their muddy traditions across bland, synthetic carpets of the new.

Edward Stone is one of the dinosaurs, a veteran of the “Great Game” of intelligence gathering, and he has a plan. It is the late ‘70s, the Shah is falling in Iran, there is turmoil in Afghanistan, and everywhere the United States seems in unruly retreat; the more perceptive agents of the CIA see “American power unraveling around the world . . . but (are) powerless to do anything about it.” Yet to Edward Stone, all this is masking a real opportunity.

The unraveling, as he sees it, is due to nothing more than bumbling leadership--a human failing which can be corrected. But on the other side, the Soviets are in real trouble, for their crisis is not just of leadership; the entire system itself is rotten, a “fabric of lies” that “would not last another generation.” Acting on his own, drawing from decades of “tradecraft,” Stone resolves to give it a little push. “I want to sabotage the machine,” he says, which he proposes to do by the creation of a paper resistance movement with imaginary CIA support in the Soviet Republics of Central Asia.

The main pawns in his game are the cynical veteran, Alan Taylor, who operates out of the agency’s station in Istanbul and believes the CIA exists “to provide a benchmark of incompetence against which other intelligence services can be measured,” and Anna Barnes, a recent recruit from academia, where she had been laboring with increasing disaffection to complete a doctorate in Ottoman history. Both, in different ways, are malcontents, which makes both perfect foils for Edward Stone.

Together, the three recruit a network whose members include a patriotic Armenian doctor, a sleazy Iranian “businessman,” a burnt-out ex-agency caseworker, an Uzbek refugee and a CIA technical whiz stationed in Athens. All of these people have different ends in mind when they join up, of course, but the only end that really matters is the private one of Edward Stone.

As Ignatius draws him, this Stone is a fascinating figure, and the world he represents is more fascinating still. Patrician and unfailingly elegant, even when trying to affect a working-class disguise, he is a holdover from the American branch of the British “old boy network,” those duty-bound aristocrats from the right backgrounds and the right schools who, for a time, told the rest of the world what was good for it and who, in their own minds, still know.

Such people were the founders of American intelligence back in the heady days of World War II and the OSS, when parachuting into occupied France or outwitting Nazis in Lisbon was something one did after graduating from the proper Ivy League college. By 1979, however, few of these upper-crust adventurers remain, and Stone is left to carry on pretty much by himself, disdainful of the new boys and--convinced that he knows better than they--determined to travel his own path.

Somehow, the Soviet Union survives his plot, as does the CIA. Naturally, so does Edward Stone. The network he has created, however, comes to a less sanguine end. Its members, those who survive, are broken and thoroughly disillusioned. Led to believe that they might change the world, they instead find themselves cast aside.

Although readers of books like “Siro” inevitably are tempted to find real-life prototypes for the characters, such an exercise here seems beside the point. The questions we are left to mull over on our own, both political and ethical, are far more central:

How do we control people like Stone? Do we control them? And if we don’t, securely confident in their professionalism and easy competence, aren’t we admitting that they’re right, that they do know what’s best for the rest of us?