An ex-spook's case for strengthening the CIA; Facing Reality, by Cord Meyer. New York: Harper & Row. $15.95.

During the past 15 years, we have become so accustomed to startling exposes written by former Central Intelligence Agency employees that we might call this the era of Books by Spooks.

Naturally, as I started to read this volume by Cord Meyer, who after becoming a newspaper columnist worked 26 years for the CIA until resigning in 1977, I expected juicy disclosures. After all, Meyer ahd headed the agency's covert action section and was involved in many of its most secret operations.

Well, sad to say, there are no disclosures -- between the confessions of ex-CIA officers and the revelations by congressional investigators, there might be nothing left to disclose. In fact, never before have a country's intelligence activities been so opened to public scrutiny, and this very openness raises serious questions as to how a democracy can square its need for efficient intelligence gathering with its desire for a large group of spy-agency overseers who share all the secrets. (As of today, although the next Congress may alter the legislative arrangement, eight congressional committees and their staffs -- some 200 persons -- oversee CIA policies and activities).

Without telling secrets then, Meyer's autobiography follow a precept laid down by Justice Oliver Wendell Holmes, who recognized it is sometimes more important to emphasize the obvious than to elucidate the obscure. Thus Meyer focuses on why he believes the CIA must be strengthened to meet US security requirements.

The Soviets, Meyer reminds us, use proxy armies (the Cubans in Angola), engage in direct aggression (from Hungary to Czechoslovakia to Afghanistan), and have the will and capacity for massive covert interventions anywhere in the world. As an esurient world power, the USSR maintains unchanged three interconnected foreign policy priorities: to defend and expand the "socialist order"; to strengthen ties with new governments and revolutionary "progressive" movements; and to pursue with the West its self-defined policy of "peaceful coexistence, detente and international trade."

The danger to the West arises, says Meyer, from the Soviet strategic superiority "that is certain to emerge in the early 1980s." It is not, however, that "the Soviet will seek to gamble everything on one final throw of the nuclear dice."

"The real danger," writes Meyer, "is that under the umbrella of their strategic strength, the Soviets will be tempted to probe continuously for weak points in Western defenses and to engage in an increasingly aggressive exploitation of targets of opportunity in the continuing struggle for allies, strategic bases, and raw materials, secure in the knowledge that at no point will a strategically inferior United States dare to risk an escalation to nuclear war."

The superiority which te USSR enjoys also extends to intelligence, to judge by Meyer's description of the KGB and its estimated force of 400,000 employees, including border guards. Of immeasurable aid to the KGB is not merely this enormous force but America's own democratic sytem.

"This difference between the open American society," writes Meyer, "and the closed Soviet state forces the American taxpayers to pay billions of finance the collection of the kind of information in the Soviet Union that is freely available to the Soviet Embassy in Washington."