The Bush administration focused on alleged weapons of mass destruction as the primary justification for toppling Saddam Hussein by force because it was politically convenient, a top-level official at the Pentagon has acknowledged.
The extraordinary admission comes in an interview with Paul Wolfowitz, the Deputy Defence Secretary, in the July issue of the magazine Vanity Fair.
Mr Wolfowitz also discloses that there was one justification that was "almost unnoticed but huge". That was the prospect of the United States being able to withdraw all of its forces from Saudi Arabia once the threat of Saddam had been removed. Since the taking of Baghdad, Washington has said that it is taking its troops out of the kingdom. "Just lifting that burden from the Saudis is itself going to the door" towards making progress elsewhere in achieving Middle East peace, Mr Wolfowitz said. The presence of the US military in Saudi Arabia has been one of the main grievances of al-Qa'ida and other terrorist groups.
"For bureaucratic reasons we settled on one issue, weapons of mass destruction, because it was the one reason everyone could agree on," Mr Wolfowitz tells the magazine.
The comments suggest that, even for the US administration, the logic that was presented for going to war may have been an empty shell. They come to light, moreover, just two days after Mr Wolfowitz's immediate boss, Donald Rumsfeld, the Defence Secretary, conceded for the first time that the arms might never be found.
The failure to find a single example of the weapons that London and Washington said were inside Iraq only makes the embarrassment more acute. Voices are increasingly being raised in the US and Britain demanding an explanation for why nothing has been found.
Most striking is the fact that these latest remarks come from Mr Wolfowitz, recognised widely as the leader of the hawks' camp in Washington most responsible for urging President George Bush to use military might in Iraq. The magazine article reveals that Mr Wolfowitz was even pushing Mr Bush to attack Iraq immediately after the 11 September attacks in the US, instead of invading Afghanistan.
There have long been suspicions that Mr Wolfowitz has essentially been running a shadow administration out of his Pentagon office, ensuring that the right-wing views of himself and his followers find their way into the practice of American foreign policy. He is best known as the author of the policy of first-strike pre-emption in world affairs that was adopted by Mr Bush shortly after the al-Qa'ida attacks.
In asserting that weapons of mass destruction gave a rationale for attacking Iraq that was acceptable to everyone, Mr Wolfowitz was presumably referring in particular to the US Secretary of State, Colin Powell. He was the last senior member of the administration to agree to the push earlier this year to persuade the rest of the world that removing Saddam by force was the only remaining viable option.
The conversion of Mr Powell was on full view in the UN Security Council in February when he made a forceful presentation of evidence that allegedly proved that Saddam was concealing weapons of mass destruction.
Critics of the administration and of the war will now want to know how convinced the Americans really were that the weapons existed in Iraq to the extent that was publicly stated. Questions are also multiplying as to the quality of the intelligence provided to the White House. Was it simply faulty given that nothing has been found in Iraq or was it influenced by the White House's fixation on the weapons issue? Or were the intelligence agencies telling the White House what it wanted to hear?
This week, Sam Nunn, a former senator, urged Congress to investigate whether the argument for war in Iraq was based on distorted intelligence. He raised the possibility that Mr Bush's policy against Saddam had influenced the intelligence that indicated Baghdad had weapons of mass destruction.
This week, the CIA and the other American intelligence agencies have promised to conduct internal reviews of the quality of the material they supplied the administration on what was going on in Iraq. The heat on the White House was only made fiercer by Mr Rumsfeld's admission that nothing may now be found in Iraq to back up those earlier claims, if only because the Iraqis may have got rid of any evidence before the conflict.
"It is also possible that they decided that they would destroy them prior to a conflict," the Defence Secretary said.
* The US military said last night that it had released a suspected Iraqi war criminal by mistake. US Central Command said it was offering a $25,000 (315,000) reward for the capture of Mohammed Jawad An-Neifus, suspected of being involved in the murder of thousands of Iraqi Shia Muslims whose remains were found at a mass grave in Mahawil, southern Iraq, last month.
The alleged mobile weapons laboratories
As scepticism grows over the failure to find weapons of mass destruction in Iraq, London and Washington are attempting to turn the focus of attention to Iraq's alleged possession of mobile weapons labs.
A joint CIA and Defence Intelligence Agency report released this week claimed that two trucks found in northern Iraq last month were mobile labs used to develop biological weapons. The trucks were fitted with hi-tech laboratory equipment and the report said the discovery represented the "strongest evidence to date that Iraq was hiding a biowarfare programme".
The design of the vehicles made them "an ingeniously simple self-contained bioprocessing system". The report said no other purpose, for example water purification, medical laboratory or vaccine production, would justify such effort and expense.
But critics arenot convinced. No biological agents were found on the trucks and experts point out that, unlike the trucks described by Colin Powell, the Secretary of State, in a speech to the UN Security Council, they were open sided and would therefore have left a trace easy for weapons inspectors to detect. One former UN inspector said that the trucks would have been a very inefficient way to produce anthrax.