For most of his life, Henry Kissinger, a man whose name is closely associated with the idea of power, did not really exercise it. He became prominent in public life from 1956, when, as a 33-year-old Harvard academic, he was recruited to advise Nelson Rockefeller – the wealthy Republican politician who seemed, at times, likely to become president. Kissinger was not, however, a conventional politician. He never stood for election and he seems to have regarded democracy – especially democracy in the United States – with some distaste. He first held political office in 1969 when the newly elected president, Richard Nixon, unexpectedly chose him as National Security Advisor. He became Secretary of State in 1973 and maintained this office when Gerald Ford succeeded Nixon as president. After that, he never served in government again. He remained influential as a commentator and adviser until he died at the age of one hundred in 2023, but in all he spent only eight years as a policymaker in Washington.

For much of his life, Kissinger was known as an author. He wrote about 19th-century statesmen – Castlereagh, Metternich and Bismarck – whom he admired in part because their long-term strategic calculations were rarely disrupted by elections. In his own time, he studied diplomacy and warfare. After he left office, he wrote books about the conduct of foreign policy that were informed by experience. He sometimes reflected on the ambiguities of his own position. He was an intellectual, but one who understood that political realities might count for more than the clarity of a well-constructed argument. He underlined the difference between providing advice and implementing policy. However, if Kissinger did not think that being a philosopher was enough, he was also painfully aware that the man he served was no king. Nixon lacked the assurance of the great 19th-century aristocratic statesmen. Kissinger looked back wistfully on Rockefeller – his first political patron and a member of the nearest thing the United States had to an aristocratic dynasty – but he appreciated that the acquisition of power in the American system often required Nixon’s gutter-fighting instincts.

Kissinger had no time to write when he was in office. He sometimes suggested that Washington life did not even allow time to think and that those who worked there were always expending the ‘intellectual capital’ they had accumulated elsewhere. For these reasons, the Kissinger tapes are particularly useful in