The US Army tried to kill or capture Muqtada al-Sadr, the widely revered Shia cleric, after luring him to peace negotiations at a house in the holy city of Najaf, which it then attacked, according to a senior Iraqi government official.
The revelation of this extraordinary plot, which would probably have provoked an uprising by outraged Shia if it had succeeded, has left a legacy of bitter distrust in the mind of Mr Sadr for which the US and its allies in Iraq may still be paying. "I believe that particular incident made Muqtada lose any confidence or trust in the [US-led] coalition and made him really wild," the Iraqi National Security Adviser Dr Mowaffaq Rubai'e told The Independent in an interview. It is not known who gave the orders for the attempt on Mr Sadr but it is one of a series of ill-considered and politically explosive US actions in Iraq since the invasion. In January this year a US helicopter assault team tried to kidnap two senior Iranian security officials on an official visit to the Iraqi President. Earlier examples of highly provocative actions carried out by the US with
little thought for the consequences include the dissolution of the Iraqi army and the Baath party.
The attempted assassination or abduction took place two-and-a-half years ago in August 2004 when Mr Sadr and his Mehdi Army militiamen were besieged by US Marines in Najaf, south of Baghdad.
Dr Rubai'e believes that his mediation efforts - about which he had given the US embassy, the American military command and the Iraqi government in Baghdad full details - were used as an elaborate set-up to entice the Shia leader to a place where he could be trapped.
Mr Sadr emerged as the leader of the Sadrist movement in Baghdad at the time of the fall of Saddam Hussein in 2003. It had been founded by his father, also a cleric, who had confronted Saddam's regime in the 1990s and had been murdered by his agents in 1999. Its blend of nationalism, religion and populism proved highly attractive to Iraqi Shia, particularly to the very poor.
Although Mr Sadr escaped with his life at the last moment, the incident helps explain why he disappeared from view in Iraq when President George Bush stepped up confrontation with him and his Mehdi Army militia in January.
Dr Rubai'e said: "I know him very well and I think his suspicion and distrust of the coalition and any foreigner is really deep-rooted," and dates from what happened in Najaf. He notes that after it had happened Mr Sadr occupied the shrine of Imam Ali in Najaf as a place of refuge. Dr Rubai'e had gone to Najaf in August 2004 to try to mediate an end to the fighting. He met Mr Sadr who agreed to a set of conditions to end the crisis. "He actually signed the agreement with his own handwriting," said Dr Rubai'e. "He wanted the inner Najaf, the old city, around the shrine to be treated like the Vatican."
Having returned to Baghdad to show the draft document to Iyad Allawi, who was prime minister at the time, Dr Rubai'e went back to Najaf to make a final agreement with Mr Sadr.
It was agreed that the last meeting would take place in the house in Najaf of Muqtada's father Mohammed Sadiq al-Sadr who had been murdered by Saddam's gunmen with two of his sons five years before. Dr Rubai'e and other mediators started for the house. As they did so they saw the US Marines open up an intense bombardment of the house and US Special Forces also heading for it. But the attack was a few minutes premature. Mr Sadr was not yet in the house and managed to escape.
Although Dr Rubai'e, as Iraqi National Security Adviser since 2004 and earlier a member of the Iraqi Governing Council, is closely associated with the American authorities in Baghdad, he has no doubt about what happened.
He sees the negotiations as part of a charade to lure Mr Sadr, who is normally very careful about his own security, to a house where he could be eliminated.
"When I came back to Baghdad I was really, really infuriated, I can tell you," Dr Rubai'e said. "I went berserk with both [the US commander General George] Casey and the ambassador [John Negroponte]." They denied that knew of a trap and said they would look into what happened but he never received any explanation from them.
The US always felt deeply threatened by Mr Sadr because, unlike the other Shia parties, he opposed the occupation and demanded that it end.
There were two attempts to crush his movement in 2004, neither of which was successful. The first, at the end of March, began with the closure of his newspaper and the arrest of one of his close advisers. A warrant for Mr Sadr's own arrest was issued. A US general said his only alternatives were to be killed or captured.
The US authorities appeared to have little understanding of the reverence with which the Sadr family was regarded by many Iraqi Shia.
The crackdown provoked a reaction for which the US was ill-prepared. The Mehdi Army, though poorly armed and untrained, took over part of Baghdad and many Shia cities and towns in southern Iraq. The US had to rush troops to embattled outposts.
A second crisis began in Najaf in August and this time the US and the recently appointed government of Iyad Allawi appear to have decided to smash Mr Sadr and his movement for ever. But they dared not assault the shrine of Imam Ali, one of the holiest Shia shrines.
Other Shia parties suspected that once Mr Sadr was dealt with they would be marginalised. The crisis was finally defused when Grand Ayatollah Ali al- Sistani, after undergoing medical treatment in London, returned to Najaf and negotiated an agreement with Mr Sadr under which he withdrew but did not disarm his forces.
The attempt to kill or imprison Mr Sadr was first revealed by Dr Rubai'e to Ali Allawi, the former Iraqi finance minister, who gives an account of what happened in his recent book The Occupation of Iraq: Winning the war, Losing the peace.
Dr Rubai'e said this weekend in Baghdad that he stands by his account given there. He does not think the Americans were planning to kill him along with Mr Sadr because he had a senior American officer with him almost all the time.
Muqtada al-Sadr is one of the most extraordinary figures to emerge during the war in Iraq,a pivotal figure leading a broad-based political movement with a powerful military wing.
The appeal of the 33-year-old Shia cleric is both religious and nationalist. He is regarded with devotion by millions. He is also a survivor and an astute politician who has often out-manoeuvred his opponents. The US and Britain have repeatedly underestimated the strength of his support.
The al-Sadrs are one of the great Shia religious families. His relative, Mohammed Baqir al-Sadr, was the founder of a politically active Shia movement and was executed by Saddam Hussein in 1980. Muqtada's father Mohammed Sadiq al-Sadr in effect founded the Sadrist movement in the 1990s. Finding he could not control him, Saddam Hussein had him murdered with two of his sons in Najaf in 1999, provoking widespread rioting.
To the surprise of all, the Sadrist movement re-emerged with Muqtada at its head during the fall of the old regime. In April 2003 it took over large parts of Shia Iraq. Its base was the vast Shia slum, renamed Sadr City, that contains a third of the population of Baghdad.
The US and its Iraqi allies regarded Muqtada as a highly threatening figure. Paul Bremer, the ill-fated US viceroy in Iraq after the invasion, detested and unwisely under-rated the Sadrists. When he moved against them in April 2004 he was astonished to see them take over much of southern Shia Iraq in a few days. Muqtada took refuge in Najaf.
There was a heavy fighting in August 2004 when the US made an all-out effort to eliminate Muqtada and his movement. Once again he survived, thanks to a compromise arranged by Grand Ayatollah Ali al-Sistani.
His movement became less confrontational. It took part in the elections in 2005, winning 32 seats out of 275. The Mehdi Army was viewed by the Sunni as an organisation of sectarian death squads.
The US began increasingly to confront the Sadrists. But they were an essential support of the Iraqi government, making it difficult for the US to move against them. When the reinforced US forces in Baghdad did threaten the Mehdi Army, Muqtada simply sent his militiamen home, and disappeared from view.