SEIZE THE MOMENT America's Challenge in a One-Superpower World By Richard Nixon Simon and Schuster. 322 pp. $25

"SECOND-CLASS intellect, first-class temperament," Oliver Wendell Holmes once said of Franklin D. Roosevelt. Just the reverse might describe Richard Nixon.

This is not the place to dwell on Nixon's character flaws, a subject that has absorbed his many biographers. But it is difficult to overlook his defensive, polemical, sometimes paranoid style. As if engaged in debate, he is constantly striving to score points over various "experts," "specialists" and "observers" whose estimates, he insists, proved to be wrong when his were correct. They include such perennial Nixon targets as government bureaucrats, newspaper commentators, liberal academics and, of course, habitues of "elitist" Georgetown dinner parties.

Not only is this peevish style annoying, but it clouds Nixon's undeniable intelligence. Whatever the peculiarities of his personality, he does have impeccable credentials in the field of international affairs, having circled the planet for decades, spoken with scores of foreign figures and helped to shape several great moments in history. So, despite himself, he deserves attention.

An inveterate traveler, Nixon ranges in this book from Eastern and Western Europe through Asia, Latin America and the Middle East. And even though his scope is broad, he does not sacrifice detail. Indeed, he has done a remarkable job of packing a vast amount of information into 300 pages.

A conspicuous fault, however, is the scant space he devotes to America's domestic problems as well as the trite solutions he offers. He dutifully deplores the high cost of health care, inadequate schools, crime, drugs and widespread poverty, but his answer is Darwinian: "Almost anyone can lead a productive life. The basic distinction we must draw is between those who choose to do so and those who choose not to do so." A bromide of that kind is unworthy of a president whose social programs were far more enlightened than those of his successors.

Nixon also tends to slide into vacuous rhetoric. He contends that the present triumph of freedom, if properly grasped, could make the United States "not just a rich society but a good society," but he fails to explain how such a transformation can occur.

He submits, as his subtitle suggests, that the demise of the Soviet Union has left only one superpower -- America. Thus, he argues, the United States must continue to play a preeminent global role. He cautions against a retreat into isolationism, but stresses that "we do not have sufficient power to remake the world in our image," and argues instead for policies based on "practical idealism and enlightened realism" -- essentially a formula for pragmatism.

Nixon offers prescriptions for each of the regions he covers. But more interesting than his proposals are his analyses of events and his vignettes of the people he has encountered. His distrust of the press notwithstanding, he would have made a fine if feisty reporter.

His chapter on the disintegration of the Soviet Union, though partly outstripped by the news, is nevertheless valuable. Advised by the scholar Dmitri Simes, to whom he gives due credit, Nixon denounces Mikhail Gorbachev -- and, predictably, Gorbachev's sympathizers in Washington and elsewhere. His criticism is unduly harsh, since Gorbachev did after all set into motion the process that led to the unraveling of the Soviet Union. But Nixon has never been known for his tact. And considering that he was writing before Gorbachev resigned, his virtual forecast of the Soviet president's collapse is prescient.

He spurns as "fatuous nonsense" the notion that the West could have saved Gorbachev by giving him economic assistance. Gorbachev's fatal mistake, Nixon asserts, was his "adamant refusal to abandon the discredited doctrine of socialism and to move away from the center's imperial domination of the republics," which "isolated him from the growing Soviet pro-reform movement."

By contrast, Boris Yeltsin is a "political heavyweight" who shrewdly staged an end run around the center to forge close ties with the major republics that shared his disdain for communism and favored private enterprise. Nixon sees in Yeltsin the tough hombre he likes to see in himself -- "a two-pistol man who . . . expresses his opinions in earthy terms and can connect with the average person." He scorns those who dismissed Yeltsin as uncouth, recalling with retrospective esteem that Nikita Khrushchev, also misjudged by the "experts" as coarse, "had the quickest mental reaction time" of any leader he ever met.

Nixon implicitly perceives his own vindication in the dissolution of the Soviet Union, whose people now agree, as he has held throughout his career, that "communism is a malignant cancer {that} must be cut out root and branch." He would not grant aid to the republics until they make a "clean break" with the past, cleanse themselves of communism and introduce genuine democracy.

On the other hand, he is curiously indulgent toward the Chinese Communists. Perhaps he expects less from them than he does from the Russians, or maybe he cannot forget the lavish welcome they accorded him during his dramatic trip to Beijing in 1972. He clearly admires their economic success and, like many Americans, he has a soft spot in his heart for China. In any case, though he criticizes their abysmal human rights record, he recommends against sanctions and urges that the Sino-American relationship be kept intact "until the current hard-line leadership passes from the scene." I am inclined to agree with his conclusion that the approach "might not be the most emotionally satisfying course of action, but it is the most sound strategically."

With all this, it is paradoxical that he calls his book Seize the Moment, a quotation from a verse by Mao Zedong, which Nixon cited in a speech during his first journey to Beijing. As a correspondent on the visit, I was surprised at the time that he had selected a paean to revolution as the text for his sermon. I later learned that a clever White House staffer in search of an apt phrase found it in the Mao poem, but I still wonder if Nixon yet knows the lines that follow. Whether he does or not, they hardly fit his present appeal for a new era of peace:

The Four Seas are rising, clouds and waters

raging,

The Four Continents are rocking, wind and thunder

roaring.

Our force is irresistible,

Away with all pests!

Stanley Karnow, whose books include "Vietnam: A History," won the Pulitzer Prize for History in 1990.