I choose Bravo Gianni, an elegant Upper East Side restaurant, for my lunch with Henry Kissinger because it is in a quiet residential area close to his office. When I have eaten out in busier places with the former secretary of state, we have been interrupted – sometimes many times – as friends and strangers come over to greet him.

Here, in a discreet and calm dining room, we will be undisturbed. The owner Gianni Garavelli greets me warmly as I sit down at one of the large tables and wait for Kissinger, who on Tuesday celebrates his 85th birthday. He strides in briskly, dressed as always in a dark suit and sombre tie. Kissinger is a man from an age when open-necked shirts were never acceptable at lunch.