Henry Kissinger, the 98-year-old, Nobel-Peace-Prize-winning, Monty Python-inspiring, former U.S. Secretary of State, believes that, perhaps more than any time since the Age of Enlightenment, the world is entering a period of disruption that needs thoughtful leaders. And the internet is not helping to produce them. In his new (and 19th) book, Leadership, Kissinger—widely admired and reviled for his management of world affairs under President Richard Nixon—uses a historian’s approach to examine six consequential world leaders who inherited difficult geopolitical situations, and in his view, overcame and improved them.