IF YOU ARE a lifelong Nixon-watcher, reviewing one of his books is a little like having to walk through an airport metal detector. You might just as well empty your pockets of knives, keys and loose change because the thing will beep if you don't. So I should acknowledge right now a grudge and a bias: Richard Nixon, by disfiguring the American political scene, has blighted my life and times.

Now, about this latest book of his. Richard Nixon has done the unforgivable for those of us who have been angered and outraged by his public performance over the years. He is making us (or me, at least) feel sorry for him. In his portrayals of selected world leaders and his efforts to come to grips with the key to and the test of greatness, there is something pathetic about his eagerness to appear entirely natural in the company he writes about, and nothing subtle about his search for elements in the careers of the great that are common to his: devastating setbacks and glorious comebacks (Churchill and de Gaulle).

What makes it sad is not only the contrivance but the evidence along the way that after all those walks on the beach at San Clemente, all the anguish of Watergate revisited on TV and in his memoirs, Richard Nixon still doesn't seem comfortable in his own skin. He is still squirming, still sore at the media, still looking for ways to tuck it to John F. Kennedy.

None of which is to say that this book is not only interesting and occasionally insightful about the leaders Nixon profiled: it is simply to say that it is doubly interesting for its insights to Nixon.

By the nature of things, historians will probably find Nixon's reminiscenses about the leaders he met while he was president more interesting than his chit-chatty conversations with those he encountered as vice president, or after he left office. Statesmen usually talk more seriously when they are talking to the U.S. president. But there are revealing glimpses of an impressive pantheon. Oddly and without explanation, Nixon includes only one American, General Douglas MacArthur. His favorite leader is Churchill, and the list runs through de Gaulle Konrad Adenauer, Nikita Khrushchev, Chou En-lai, all of whom rate a chapter, and a further list of somewhat lesser lights (Anwar Sadat, the shah of Iran, David Ben-Gurion, Golda Meir, Nehru, Sukarno, Nkrumah).

But they appear as if on a transparency, in gossamer recollections of Leonid Brezhnev's "full-figured" masseuse and the Arpege with which she was perfumed; his scatological exchange with Nikita Khrushchev on which kind of manure, horse or pig, smells worse; on Sadat's opinion that Israel's Menachem Begin is "crazy like a fox."

Pull away the transparency, however, and there's the smiling/scowling face of Richard Nixon, struggling in his tales of momentous encounters with great men to tell us things that will make us think better of him -- while trying not to let the effort show. He preaches a lot about the ingredients of greatness and some of it is awfully platitudinous. "The leader must aways weigh consequences; this becomes second nature to him." "No one becomes a major leader without a strong will, or without a strong ego." "The successful leader does not talk down to people. He lifts them up."

But a lot of it would have you believe that Richard Nixon, whatever his high crimes and misdemeanors, was really just being, well, a leader -- like Abraham Lincoln, for example. "We think of [him] as a supreme idealist, and he was," Nixon writes. But in the interest of preserving the Union, Nixon goes on, Lincoln "broke laws, he violated the Constitution, he usurped arbitrary power, he trampled individual liberties." So what's all this about a little obstruction of justice?

Nixon argues that "in evaluating a leader, the key question about his behavioral traits is not whether they are attractive or unattractive, but whether they are useful. Guile, vanity, dissembling -- in other circumstances these might be unattractive habits, but to the leader they can be essential." So what's the fuss about a cover-up?

Moving right along in somewhat the same vein, Nixon praises Churchill's role of "Cassandra" in his pre-World War II warnings about the German menace and reveals that Churchill was so effective largely because he regularly received "inside information" from civil servants who were "worried about the blindness of their superiors... without their facts and figures, he would have been dismissed out of hand as a bellicose blowhard."

Nimbly, Nixon moves in to block off an apparent inconsistency; nothing in the performance of those British civil servants could possibly find a parallel in the performance of those who leaked the Pentagon Papers -- and never mind that they too were worried about the "blindness of their superiors."

We were at war, Nixon argues (and never mind, either, that no war had been declared) and he is "certain that Churchill would have considered the leaking of the Pentagon Papers during wartime to be treasonable." Certain? As for Churchill's sources, says Nixon, they "would never have dreamed of giving their raw information to a reporter for publication." He does not quite square that with the fact that the information was of no value to Churchill unless he used it in public debate, which is what he did.

Once he has Douglas MacArthur firmly on a pedestal, he uses him to clobber John F. Kennedy posthumously. MacArthur, he writes, spoke "disparagingly of Kennedy's PT-boat exploit," saying that Kennedy "could have been court-martialed for his poor judgment." MacArthur, in these private conversations, was "brutally critical of Kennedy," calling him "just dumb when it comes to decision making."

To be fair, there is much better stuff, not so self-serving and often revealing, about the thinking and the character of the extraordinary collection of large figures who crossed Nixon's path over a long career. But the self-interest is almost certainly going to put historians, working from these reminiscences, to a heavy test, for there is almost no documentation of much of what Nixon recites -- at least none is furnished.

Still, Nixon was a leader himself long enough and met enough of them to have given leadership a lot of thought.So it is valuable to have his assessments and conclusions.The flaw is simply the same old, familiar flaw we find in most of Richard Nixon's writings, going back to Six Crises, where once again his picture of critical events is smudged by a self-centered preoccupation. Richard Nixon remains the only man in American political history who could make a personal crisis in his own public life out of Dwight D. Eisenhower's heart attack.