Cigarettes, Martinis and Other Deceptions : THE DECEIVER, <i> By Frederick Forsyth (Bantam Books: $22.50; 496 pp.)</i>

It’s often assumed that novelists are a thrifty lot who squirrel away literary odds and ends in repositories usually called “The Trunk” by everyone save the novelists. The Trunk is said to contain a wealth of abandoned beginnings, unsold short stories, brilliant fragments, excised episodes and jettisoned characters--all to be profitably recycled at some future date.

That future date apparently arrived last year for John le Carre with the publication of his “The Secret Pilgrim,” which consisted of loosely joined, but vintage, Cold War episodes featuring the redoubtable George Smiley. Frederick Forsyth, another highly regarded British novelist, now offers “The Deceiver,” which also consists of long and loosely joined episodes that feature Sam McCready, a 51-year-old British spy, who is about to be made redundant by the Cold War’s end.

Forsyth himself seems unabashedly nostalgic for the old days of death and double cross. In a curious dedication, he writes: “The Cold War lasted forty years. For the record, the West won it. But not without cost. This book is for those who spent so much of their lives in the shadowed places. Those were the days, my friends.”

It was during Margaret Thatcher’s reign as prime minister that the British Secret Intelligence Service (SIS) established a new section, which, Forsyth assures us, was called Deception, Disinformation and Psychological Operations--mercifully shortened to Dee-Dee and Psy Ops. The man who ran this section, or desk, was Sam McCready, a widower and former field agent, who now lives “alone in a little flat in Kensington,” the neighborhood of many another fictional secret agent.

Although the Cold War is over, a new war has broken out within the British government. This one is over who will be awarded the new job slots in the burgeoning British embassies and consulates in what were once thought of as Iron Curtain countries. The Foreign Office, it seems, wants to move the SIS spies out and its own people in.

It’s decided that someone must set a precedent for the purge that will follow. McCready is picked as the scapegoat and given three choices--the same choices that all other redundant spies will be given: He can retire on a reduced pension, accept a glorified clerical job in Britain or demand a hearing. If he chooses the hearing, he can appoint a fellow SIS colleague to present his case. McCready opts for the hearing and asks Denis Gaunt, a fellow spy, to represent him.

Gaunt rises before the appeals board--made up of Civil Service mandarins--and proceeds to spin four tales about the daring and, he hopes, exculpatory feats of espionage that McCready, nicknamed the Deceiver, performed for Queen and country.

The first adventure is a 107-page-long tale called “Pride and Extreme Prejudice,” which takes place in what used to be East Germany. Its flavor can be had from a scene in which McCready says, “I have to go over . . . because we have a man over there. He is sick, very sick. But if I can bring him out, it will probably break the career of the one who now heads Abteilung II. Otto Voss.”

This is vintage Cold War stuff that carries you back to the early days of James Bond in his prime--before he cut down on cigarettes and all those martinis.

As soon as Gaunt ends his account of McCready behind the Iron Curtain, the hearing board’s chief hatchet man snippily says, “ ‘Thank you for reminding us of the events of 1985, though I feel one might point out that in intelligence terms, that year now constitutes a different and even vanished age.’ ”

Thus Forsyth, a canny author, preempts those who might murmur that this first long, long short story is, well, a trifle old-hat. Those who do utter such thoughts run the risk of siding with the novel’s principal villain.

The second tale spun by Gaunt is called “The Price of the Bride” and deals with a nasty trick the KGB tries to play on the CIA--only to have it discovered by McCready. The trick involves the use of an impersonator, or double, and some other fanciful trade-craft. A ruminative Russian tells McCready of its genesis: “Project Potemkin started eight years ago. . . . The aim was to denounce a senior CIA officer as a Soviet plant, but in a manner so convincing and with such a wealth of apparently fireproof evidence that no one could reasonably not be taken in.”

McCready, of course, wasn’t taken in and neither, I suspect, are any number of spy novelists who have employed similar plots. But a couple of the appeals-board members seemed impressed and, thus encouraged, Gaunt begins his third tale.

This one is called “A Casualty of War” and has to do with IRA gunrunning and a plot to assassinate the American ambassador to the Court of St. James’s. Once McCready has spoiled the IRA’s plans, he muses aloud about his own: “Oh, I will go back to Century House and start again. And go back each night to my small flat and listen to music and eat my baked beans.”

The final tale in defense of McCready deals with a Caribbean island-state that’s a member of the British Commonwealth and about to choose between full independence and the status quo. The story is called “A Little Bit of Sunshine,” and in it McCready saves the islanders from the forces of evil, thus allowing them to remain poor but happy and, of course, British.

Each of these four long short stories offers the charm of the recent past and the reward of Forsyth’s meticulous research. Reading them, I again had the feeling, which I’ve had since his splendid “The Day of the Jackal,” that Forsyth researches very carefully and writes very rapidly. He often reads like a gifted wire- service reporter on an impossible deadline--which, if nothing else, certainly moves things right along.

As for McCready, the sad Deceiver, he remains unrepentant, unreconstructed and still convinced that “there’s a bloody dangerous world out there, and it’s not getting any less dangerous.”

For the sake of all those who read and write spy thrillers, one must hope that Sam McCready is right.