In the epilogue to the first volume of his biography of Henry Kissinger, The Idealist, historian Niall Fergusson notes that he asked Yale university professor, John Gaddis, whether he agreed with his designation of Dr K. as a foreign policy “idealist.” That assessment contrasted with the conventional view of the former U.S. Secretary of State as archetypal national security “realist,” the kind who hangs a picture of Otto von Bismarck in his study.