The most important anniversary of the year has been the 40th anniversary of 11 September 1973 – the crushing of the democratic government of Chile by General Augusto Pinochet and Henry Kissinger, US secretary of state. The National Security Archive in Washington has posted new documents that reveal much about Kissinger’s role in an atrocity that cost thousands of lives.

In declassified tapes, Kissinger is heard planning the overthrow of President Salvador Allende with Richard Nixon. They sound like Mafiosi thugs. Kissinger warns that the “model effect” of Allende’s reformist democracy “can be insidious”. He tells the director of the CIA, Richard Helms: “We will not let Chile go down the drain,” to which Helms replies: “I am with you.” With the slaughter under way, Kissinger dismisses a warning by his senior officials of the scale of the repression. Secretly, he tells Pinochet, “You did a great service to the west in overthrowing Allende.”

I have known many of Pinochet’s and Kissinger’s victims. Sara De Witt, a student at the time, showed me the place where she was beaten, assaulted and electrocuted. On a wintry day in the suburbs of Santiago, we walked through a former torture centre known as Villa Grimaldi, where hundreds like her suffered terribly and were murdered or “disappeared”.

Understanding Kissinger’s criminality is vital when trying to fathom what the US calls its “foreign policy”. Kissinger remains an influential voice in Washington, admired and consulted by Barack Obama. When Israel, Saudi Arabia, Egypt and Bahrain commit crimes with US collusion and weapons, their impunity and Obama’s hypocrisy are pure Kissinger. Syria must not have chemical weapons, but Israel can have and use them. Iran must not have a nuclear programme, but Israel can have more nuclear weapons than Britain. This is known as “realism” or realpolitik by Anglo-American academics and think tanks that claim expertise in “counterterrorism” and “national security”, which are Orwellian terms meaning the opposite.

In recent weeks, the New Statesman has published articles by John Bew, an academic in the war studies department of King’s College London which the cold warrior Lawrence Freedman made famous. Bew laments the parliamentary vote that stopped David Cameron joining Obama in lawlessly attacking Syria and the hostility of most British people to bombing other nations. A note at the end of his articles says he “will take up the Henry A Kissinger Chair in Foreign Policy and International Relations” in Washington, DC. If this is not a black joke, it is a profanity on those like Sara De Witt and Kissinger’s countless other victims, not least those who died in the holocaust of his and Nixon’s secret, illegal bombing of Cambodia.

This doctrine of “realism” was invented in the US after the Second World War and sponsored by the Ford, Carnegie and Rockefeller Foundations, the Office of Strategic Services (a forerunner of the CIA) and the Council on Foreign Relations. At the great universities, students were taught to regard people in terms of their usefulness or their expendability: in other words, their threat to “us”. This narcissism served to justify the cold war, its moralising myths and cataclysmic risks, and, when that was over, the “war on terror”. Such a “transatlantic consensus” often found its clearest echo in Britain with the British elite’s enduring nostalgia for empire. Tony Blair used it to commit and justify his war crimes until his lies got the better of him. The violent deaths of more than a thousand people every month in Iraq are his legacy; yet his views are still courted and his chief collaborator, Alastair Campbell, is a jolly after-dinner speaker and the subject of obsequious interviews. All the blood, it seems, has been washed away.

Syria is the current project. Outflanked by Russia and public opinion, Obama has now embraced the “path of diplomacy”. Has he? As Russian and US negotiators arrived in Geneva on 12 September, the US increased its support for the al-Qaeda affiliated militias with weapons sent clandestinely through Turkey, eastern Europe and the Gulf. The Godfather has no intention of deserting his proxies. Al-Qaeda was all but created by the CIA’s Operation Cyclone, which armed the mujahedin in Soviet-occupied Afghanistan. Since then, jihadists have been used to divide Arab societies and in eliminating the threat of pan-Arab nationalism to western “interests” and Israel’s lawless colonial expansion. This is Kissinger-style “realism”.

In 2006, I interviewed Duane “Dewey” Clarridge, who ran the CIA in Latin America in the 1980s. Here was a true “realist”. Like Kissinger and Nixon on the tapes, he spoke his mind. He referred to Salvador Allende as “whatshisname in Chile” and said “he had to go because it was in our national interests”. When I asked him what gave him the right to overthrow governments, he said, “Like it or lump it, we’ll do what we like. So just get used to it, world.”

The world is no longer getting used to it. In a continent ravaged by those whom Nixon called “our bastards”, Latin American governments have defied the likes of Clarridge and implemented much of Allende’s dream of social democracy – which was Kissinger’s fear. Today, most of Latin America is independent of US foreign policy and free from its vigilantism. Poverty has been cut almost by half; children live beyond the age of five; the elderly learn to read and write. These remarkable advances are invariably reported in bad faith in the west and ignored by the “realists”. That must never lessen their value as a source of optimism and inspiration for all of us.

John Pilger’s new film, “Utopia”, will have its premiere at the National Film Theatre in London on 3 October and open in cinemas in November