In comparing his biography of Henry Kissinger with James Boswell’s Life of Samuel Johnson, the Scottish historian Niall Ferguson shows no lack of ambition. This exhaustive study, the first of two volumes, was suggested by the subject, who in 2004 put at Ferguson’s disposal more than 150 boxes of private papers, on condition that quotations on purely personal matters should not be used. The result is an engrossing intellectual history of a man deemed by Ferguson to be “one of the most important theorists about foreign policy ever to be produced by the United States of America”. But Kissinger the person, unlike Boswell’s Johnson, remains tantalisingly distant, as, one suspects, he would want to be. It does not help any biographer that he dismisses his childhood