ON NOVEMBER 18, 1943 a young second lieutenant in the United States Marine Corps confided to his journal his feelings on moving out for active service.

The departure, he wrote, marked "the final step in the awakening of him who was once an incurable dreamer, the final decision . . . to see things as they are, instead of as one wishes them to be."

Seven months later, Lt. Cord Meyer was blinded in one eye by a Japanese grenade lobbed into his foxhole. He described the experience movingly in a short story published in the Atlantic Monthly. In that same story, he also recorded his emotions when one of the men in his platoon was killed.

"I wish," he wrote, "that all those in power, countrymen and enemy alike, who decided for war, all those who profit by it, lay dead with their wealth and their honors and that Everett stood upright again with his life before him."

Meyer emerged from the hospital determined to spend his life working to prevent war. And that, according to his lights, is what he has done.

He contemptuously dismisses as "simplistic demonology" any suggestion that there has been any contradiction or discontinuity in his career.

Yet his is a surprising story. If he is now "facing reality," it must be very different from what he once wished it to be. His dreams have been cured.

After spending four years from 1947 to 1951 working for world government as a leading advocate of the World Federalist movement,he has spent most of the rest of his life working for "the government," as the Central Intelligence Agency used to be coyly known.

With a rapidity which reflected his undoubted ability, he rose through the upper ranks. From 1954 to 1962, as chief of the international organizations division of the CIA's deputy directorate for plans,he had direct responsibility for CIA infiltration of U.S. and international trade union and student organizations.

In 1967, he was promoted to the number two job in the "plans" side of the agency, with responsibility, under Thomas Karamessines, for the collection of secret intelligence abroad and counter-intelligence against foreign agents, as well as for covert action, "political, paramilitary or propagandistic."

Cord Meyer, in fact, was one of the ablest (dare one say the best and the brightest?) of that generation of "liberals" who dominated the CIA from the fall of McCarthy to the fall of Nixon.

They acquired their liberal reputation, no doubt, more because of their impeccable social and educational backgrounds (in Meyer's own case, St. Paul's, Yale and Harvard) than because of any very radical views. Still, they did tend to evince a certain preference for the center-left, and a certain distaste for the coarser styles of conservatism.

Unfortunately, it is hard for an outsider to avoid the impression that they were not really very good at their job.

Certainly during their years of power the agency stumbled from one spectacular gaffe to another. Worse, it either failed to anticipate, or failed to understand, an alarmingly high proportion of the changes that were happening in the world.

Meyer's autobiogrphy mirrors that gap between promise and performance. His knowledge and intelligence are as undeniable as his courage and his experience. He writes with cogency and a certain style.

He offers authoritative accounts of several intriguing episodes: his own "trial" within the agency on absurd charges of communist sympathy in 1953-4; the inner history of Radio Free Europe and Radio Liberty, and of the CIA's infiltration of the National Student Association; the CIA's role in Chile between 1958 and 1973; the Soviet and Cuban intrigues in Africa in 1974-6.

Meyer returned from London, where he was CIA station chief, in 1976 and accepted assignments studying both the Soviet strategic threat and international terrorism before retiring to write a newspaper column under the tutelage of his friend Charles Bartlett in 1978.

The second half of his book makes little pretense at being autobiographical, and is given over to a forceful presentation of Meyer's -- and no doubt the agency's -- view of the Soviet threat. The only hopeful note he offers lies in the rise of dissent in the Soviet Union.

Meyer may have left the agency, but readers who expect to find in his book a view of the world that differs significantly from the agency's will be disappointed. (Almost the only exceptions are those instances where he allows himself to be bitchy about former colleagues. He exonerates William Colby of what Gibbon would have called "the grosser and more scandalous charges," and insists Colby was guilty of no more than "atrociously bad judgment and appalling naivete!")

He either simply does not understand, or refuses to acknowledge, why so many men and women of good will, with no treasonable or even naive sympathies with the Soviet Union, still found the CIA's behavior in so many particulars so hard to stomach.

At times the disingenuousness of his defense is almost comic. He argues, for example, that secret financing of the NSA "clearly respected and preserved [its] democratic integrity." He expresses gratitude for the Indispensable assistance of the intelligence services of our democratic allies," without appearing to be aware that among the more indispensable have been Savak in Iran, Boss in South Africa, and others in not-so-democratic allies from Spain to Korea.

With the air of a man offering a tentative opinion of an entirely personal kind, he comes down again and again, comme par hasard, on precisely the position the agency (perhaps in many cases on his own previous insistence!) has officially staked out.

What we cannot know, of course, is where or whether disingenuousness becomes disinformation. Meyer's defense of the CIA's conduct in Chile, for example, is convincing up to a point. He may be telling the truth when he insists that the Cubans really did move into Angola before the South Africans did.

His account is "authoritative." He has seen the cables; we have not. But he so doggedly defends the agency's line wherever there is a figleaf of a perimeter to defend, that he leaves me in a state of mind where I am scarcely ready to believe anything merely because he says it is so. After all, wouldn't we have made proper fools of ourselves in the past if we had gone on believing all the things he and his friends told us?