Few people can claim as much influence over the shape of the modern world as Henry Kissinger. The former US Secretary of State and Nobel Peace laureate is loved, loathed and listened to - for the decisions he took, the attitude he espoused and for his knowledge and analysis of world affairs. In 2022, James Naughtie travelled to Kissinger's home to discuss six great leaders and the lessons they taught, as Kissinger reflected on his own role in creating the modern world.