Urquhart, author of the 1972 Dag Hammarskjold biography, tells of his own life from an English boyhood through a 40-year career at the U.N., where he served as Under Secretary-General. Urquhart joined the nascent U.N. in 1946, fresh from British airborne intelligence and with an Oxford education. For years he served under Ralph Bunche, eventually succeeding to his position; and from his close contact with all the Secretaries General, he draws a strong portrait of each, from the reticent, brilliant Hammarskjold to the rather mediocre, camera-happy Waldheim. (This book was largely written before the Waldheim war record revelations.) His asides on many world leaders are equally cogent. He freely admits the U.N.'s flaws--a Security Council that doesn't work as first intended, the circus of rhetoric--but chides all sides, particularly the Reagan Administration, for U.N.-bashing, and offers forceful, detailed accounts of the U.N.'s indispensable role, admittedly not always successful, in trying to resolve some of the world's thorniest conflicts. Once on the world stage, Urquhart lets his personal life disappear--a divorce is barely mentioned--which is something of a loss after the entertaining account of his youth in the book's first quarter. But his detailed histories of complicated diplomatic efforts should be of real value to those interested in the U.N.'s role in world affairs.