On December 17th, 1983, Ronald Reagan's special envoy for the Middle East flew into the Iraqi capital, Baghdad. He carried a personal letter for Saddam Hussein, written by Reagan himself.
Howard Teicher, the State Department official who accompanied the special envoy, later told the American journalist Alan Friedman the import of the letter: "Here was the US government coming hat-in-hand to Saddam Hussein and saying: 'We respect you, we respect you. How can we help you? Let us help you'."
The letter was the beginning of an American policy of forging an alliance with the vile Iraqi dictator. Over the next seven years the US would support Saddam's ambitions to become a regional military superpower, feeding his aggressive megalomania while turning a blind eye to his horrific violence against his own people.
The name of the special envoy who carried the letter is Donald Rumsfeld. He is now, as US Defence Secretary, preparing to lead a war to save the world from Saddam.
Later today Tony Blair will publish his long-awaited dossier on Iraqi plans to develop weapons of mass destruction, in particular an atomic bomb. It will not, we are told, contain proof that the Baghdad regime is on the point of getting a usable nuclear weapon, but it will show that it is working hard towards that end.
The point of the dossier will, of course, be to provide the justification for the war that George W. Bush, Donald Rumsfeld and Blair seem determined to fight.
In fact, we don't need a dossier to tell us that Saddam Hussein wants nuclear weapons. As long ago as 1975 he boasted that he was taking "the first concrete step toward the production of the Arab atomic weapon". Six years later, Israeli jets bombed the Osirak reactor outside Baghdad, which they believed - with good reason - to be the centre of an atomic weapons programme.
When UN inspectors went into Iraq after the last Gulf War, they found that programme to be well advanced.
Western leaders know all about this, for the very good reason that their countries were up to their necks in it. As the late lamented American comedian Bill Hicks put it: "How do we know Saddam has weapons of mass destruction? We looked at the receipt."
The Osirak reactor was known in France as Ochirac because Jacques Chirac, then French prime minister, now President, supplied the materials and technology for its construction. The Reagan and Bush administrations in the US in the 1980s pursued a conscious, consistent policy of arming Saddam so that he could become the regional guardian of US interests.
In Britain, as the Scott inquiry subsequently showed, the Thatcher and Major administrations pursued a secret policy of allowing the British company Matrix Churchill to supply Saddam with the technology to construct warheads and missiles.
The administration of George W. Bush's father granted scores of export licences for pieces of equipment that were clearly intended to help Saddam construct his nuclear weapon.
To take just one example, the UN inspectors found in Iraqi installations a supply of nuclear-grade vacuum-pump oil. This is a highly specialised product, used to lubricate the centrifuges that make uranium suitable for use in an atomic bomb. It's not the sort of stuff that you have hanging around on a shelf in your garage.
You only want it if you're in the bomb-making business.
And where did the Iraqi nuclear-grade oil come from? The inspectors traced it back to the Du Pont chemical plant in Delaware. It was exported under licence from the Bush administration in February 1989.
Within a few months the Iraqis tested a modified Scud missile rocket that had a range of a thousand miles. It was perfectly obvious that Iraq was on the verge of having, not just an atomic bomb, but a system for delivering it. Subsequently declassified internal US government documents spoke of "a major nuclear proliferation risk with Iraq" and warned that the Baghdad regime was getting materials for its nuclear programme from the US.
Yet, at this very time, the US government actually invited Iraqi nuclear scientists to a military symposium on the technology of nuclear explosions in Portland, Oregon.
Even after Saddam appeared on Iraqi television with a nuclear detonator in his hand, and then openly declared his possession of "advanced chemical weapons" , US policy did not change. Right up to the invasion of Kuwait in April 1990, the US still saw Saddam as a valuable ally.
The lesson to be drawn from all of this ought to be obvious. International policies should never be based purely on whatever the US decides, from time to time, is in its national interest. An international order can only be built on consistent principles, not on everyone falling into line when the US decides that a monster is good when he's our monster and bad when he's not.