Active and concerned with international politics to the very end, Henry Kissinger has covered almost a century of practical thinking on world order: from his own experience, as a German Jew, of the democratic decline in Europe in the first third of the 20th century, which fed his reflections as a young university student already emigrating to the United States on the balance of power between the powers, to the new order shaped by the consolidation of China as a superpower.

His latest books were "On China" (2011), in which he updated his vision of a country closely linked to his own "bequest" (Richard Nixon's trip to Beijing in 1972, prepared by himself), and "World Order" (2014), in which he analyzed the new stage the world is going through once the brief unipolar moment brought about by the end of the Cold War had come to an end. Still on the verge of his 100th birthday, celebrated last May, Kissinger published "Leadership: six programs of study on global strategy" (2023), which compiled considerations on decision-making on the world stage, as his most memorable work, "Diplomacy" (1994), had done, recapitulating his experience at the head of US foreign policy between 1969 and 1977, first as Nixon's National Security Advisor and then Secretary of State under Nixon and his successor, Gerard Ford.

The accent here on his intellectual weight is to emphasize that above and beyond a man of action -he was the one who inaugurated airplane diplomacy, on long journeys through the capitals of countries in conflict- Kissinger was dominated by an interest in ideas and strategy, although certainly without the execution of his designs from power we would not be remembering him with the same intensity today. In 2011 I had the opportunity to talk to him alone in his office in New York, in an interview for a Spanish newspaper: regardless of his age, his eyes showed great vivacity, moving from one international issue to another. Despite the imbalance of baggage staff and intellect, Kissinger welcomed with interest the opinions he asked me for, predisposed to a two-way dialogue unusual in a status like that one.

Kissinger has been persecuted for some decisions made during his service in the US Administration -some of his own, others attributed to him from the ideological trenches-, but this is part of the fate of political action, marked by successes and mistakes, applause and misunderstandings. In his case, however, the "black legend" propagated by many around the realist theory of international relations is added. Kissingerian "Realpolitik" was not a carte blanche for U.S. military interventions anywhere on the planet; there were some, as there were also coups d'état encouraged by Washington, but this also occurred under previous administrations (Wilson, Eisenhower...) and yet these did not carry the sambenito. Kissinger's realism meant understanding that the national interest knows no perpetual friends or enemies -Richelieu had already said so-, and that the best way to avoid war is the balance of power; when there are few actors, this basically consists of triangulating: the rapprochement with China to prevent an alliance between Beijing and Moscow against the United States was a major operation that would eventually lead to the fall of the Berlin Wall without reaching the nuclear conflagration that was so much feared.