James B. Conant (1893-1978) was one of the giants of the American establishment in the twentieth century. President of Harvard University from 1933 to 1953, he was also a scientist who led the US government's effort to develop weapons of mass destruction, and his story mirrors the transition of the United States from isolationism to global superpower at the dawn of the nuclear age. 'This splendid portrait of Conant ... illuminates the life of a pivotal figure in the making of US nuclear, scientific, educational, and foreign policy for almost half a century. But the book is much more: it is...