BOOK REVIEW / BIOGRAPHY : A Low-Key Look at a Maker of Milestones : RALPH BUNCHE: An American Life; <i> by Brian Urquhart</i> ; Norton; $27.50, 496 pages

Yitzhak Shamir, a leader of the so-called Stern Gang and the future prime minister of Israel, was one of the men who ordered the assassination of United Nations mediator Count Folke Bernadotte in 1948. Only a chance delay at the airport spared the life of a colleague who worked with Bernadotte, an African-American diplomat named Ralph Bunche.

And so it fell to Bunche to undertake the negotiations of a truce between the new state of Israel and its Arab enemies.

“In a virtuoso display of personality, stamina and skill, he successfully negotiated four armistice agreements and gave the Middle East . . . the vital first step toward a peaceful settlement,” writes Brian Urquhart in his new biography of Bunche.

Bunche’s work on behalf of the U.N. was honored with a Nobel Peace Prize, and he deserves a place beside fellow Nobelist Martin Luther King Jr. in the pantheon of black Americans whose lives are a moral example to men and women of all races. And yet, only two decades after his death, Bunche’s name is rarely invoked and his career as a peacemaker is nearly forgotten.

Urquhart, a former career diplomat who also authored a biography of the late U.N. Secretary-General Dag Hammarskjold, has set himself the task of reacquainting us with Ralph Bunche in a substantial book that encompasses Bunche’s youth in Los Angeles, his education and travels in the ‘20s and ‘30s, and his life’s work as a diplomat who invented the role of the United Nations as a global peacekeeper.

Bunche, Urquhart writes, is very much a local hero in Los Angeles--or, at least, he ought to be. Bunche’s family arrived in Southern California shortly after World War I, and he attended Jefferson High School in South-Central. All the while, he worked as a “pig boy” at the Los Angeles Times--his job was to carry lead ingots, called pigs, to the Linotype machines in the composing room. He went on to study at UCLA, then Harvard and Howard University.

Urquhart characterizes the young Bunche as “a radical scholar-activist” whose first ambition was “to serve the cause of black Americans.” But Bunche’s studies and travels in world capitals and colonial backwaters set him on a path that carried him to the Office of Strategic Services during World War II, the Department of State and the United Nations.

As it turned out, Bunche was destined to show the U.N. flag in hot spots around the world--not only in the Middle East during the Suez crisis and the Six-Day War but also Lebanon, Cyprus, Yemen and the Congo.

Much of “Ralph Bunche” is an insider’s account of the day-to-day travails of a hands-on diplomat who deserves to be credited for inventing “shuttle diplomacy.”

We are given surprising and illuminating glimpses of world leaders in unguarded moments, and we are even shown an occasional moment of diplomatic levity. Urquhart reveals, for example, the notes that Hammarskjold and Bunche used to exchange during meetings of U.N. committees and assemblies.

“B. What is it in the legal approach that induces men to abandon common sense and even morality in pursuit of a legal point?”

“H. Sometimes I believe--as a lawyer and a diplomat--that law is even more demoralizing than diplomacy.”

Only rarely, however, are we allowed a glimpse into Bunche’s inner life. He came under suspicion during the McCarthy era, he feuded with King and other black leaders, his son was drafted for service in Vietnam and his daughter committed suicide--and yet we do not really know how he felt about any of these crises. We are left with only a few intriguing flashes of intimacy, including the sometimes volatile letters he exchanged with his wife, Ruth.

“I know you think you are the Miracle Negro with the whites, but I am sure you are just a novelty,” she once wrote to him during one of their forced separations. “They can get two men’s work out of one from you, though it may be killing you and hurting your family.”

Urquhart worked closely with Bunche during his own long career at the U.N., and he succeeded Bunche in the sensitive position of undersecretary for “Special Political Affairs.” And so we should not be surprised to detect a tinge of affection in this account.

Indeed, what is more surprising is the cool and correct tone that invariably prevails in “Ralph Bunche.” Urquhart, whose diplomatic instincts obviously run deep, stands at a respectful distance from his former colleague and refuses to step out from behind the role of the scholarly biographer.

Urquhart’s reserve, in a real sense, is the book’s only flaw. “Ralph Bunche” is a work of serious historical scholarship, but it lacks the ache of emotion or the fire of passion that might make Bunche come alive for a generation that does not know him.

Ironically, Urquhart reminds us that Bunche and his work still offer a model for making peace in our times. Bunche’s armistice agreement between Israel and the Arab countries, as Urquhart points out in a footnote on the very last page of his book, was used as a model for a 1992 cease-fire between the Bloods and the Crips.

“At the time of writing,” he notes, “the truce is still in effect.”