On December 20 1954, a woman known as Marion Keech gathered her followers in her garden in Lake City, Illinois, and waited for midnight, when flying saucers were supposed to land and save them from huge floods about to engulf the planet.

Keech had received news of the impending deluge from Sananda, a being from the planet Clarion, whose messages she passed on to a small group of believers. Unbeknown to her, the group had been infiltrated by a University of Minnesota researcher, the social psychologist Leon Festinger.

As dawn rose on December 21 with no flying saucer in sight, Keech had another revelation. Sananda told her that the group's advanced state of enlightenment had saved the entire planet. They rejoiced and called a press conference. "A man with a conviction is a hard man to change," wrote Festinger in his book on the cult, When Prophecy Fails. "Tell him you disagree and he turns away. Show him facts and figures and he questions your sources. Appeal to logic and he fails to see your point."

George Bush is a man of conviction and clearly a hard man to change. When reality confronts his plans he does not alter them but instead alters his understanding of reality. Like Keech and her crew, he stands with a tight band of followers, both deluded and determined, understanding each setback not as a sign to change course but as further proof that they must redouble their efforts to the original goal.

And so we watch the administration's plans for a military attack against Iran unfold even as its official narrative for the run-up to the war in Iraq unravels and the wisdom of that war stands condemned by death and destruction. As though on split screens, we pass seamlessly from reports of how they lied to get us into the last war, to scenes of carnage as a result of the war, to shots of them lying us into the next one.

One moment we see the trial of Dick Cheney's former deputy, Lewis "Scooter" Libby, revealing how the administration sought to discredit critics of the plans to invade Iraq; the next we see them discrediting critics of their plans to attack Iran. On one page, newly released documents reveal how the defence department contorted evidence to justify bombing Baghdad; on the next, the administration is using suspect evidence to justify bombing Iran.

"It is absolutely parallel," Philip Giraldi, a former CIA counter-terrorism specialist, told Vanity Fair magazine. "They're using the same dance steps - demonise the bad guys, the pretext of diplomacy, keep out of negotiations, use proxies. It is Iraq redux."

The administration, of course, denies this. Despite the fact it has ordered oil reserves to be stockpiled and has just sent a second aircraft carrier as well as more patriot missiles and minesweepers to the Gulf, they swear these allegations are groundless. Robert Gates, the new defence secretary, recently insisted: "I don't know how many times the president, secretary [of state Condoleezza] Rice and I have had to repeat that we have no intention of attacking Iran."

The sad fact is Gates can say it as many times as he likes because no one believes him. In April 2002, Bush told Trevor McDonald: "I have no plans to attack [Iraq] on my desk." An $8 cab ride to the Pentagon and Bush would have found the plans on Donald Rumsfeld's desk. He knew this because he put them there four months earlier. On November 21 2001, he asked Rumsfeld: "What kind of war plan do you have for Iraq?"

True they are pursuing diplomatic avenues to derail Iran's nuclear programme, but we now know that this may be little more than a sideshow. The day before Iraq was due to let in UN weapons inspectors, Bush told Rumsfeld and the head of central command, General Tommy Franks, to "dissociate a big deployment or build-up from what Colin [Powell] is doing on the diplomatic front ... Don't make it look like I have no choice but to invade".

The aim here isn't to reprosecute the case against the Iraq war - in almost every venue but the White House and Downing Street that has been won - but to illustrate that the duplicities from that war and a possible next one are playing out concurrently. Whatever excuses people make for backing an attack on Iran, what they can't say is they didn't know.

Nor does it mean America will attack tomorrow. But it does mean they are almost ready to attack today. "Targets have been selected," says Vincent Cannistraro, a US intelligence analyst. "For a bombing campaign against nuclear sites, it is quite advanced. The military assets to carry this out are being put in place. We are planning for war."

These plans run not in historical parallel with the period before the attack on Iraq, but rather in lockstep with the current situation there. They do not so much replicate the preparations as seek to exploit the dire situation caused by the invasion.

For the time being, US focus has shifted from Iran's desire to acquire a nuclear bomb - a development that should be resisted by diplomatic means, because it will undermine prospects of stability and peace in the region - to its involvement in Iraq. The accusation is that the Iranians are supplying insurgents with a bomb known as the "explosively formed penetrator", which, the Pentagon says, is responsible for killing at least 170 US military personnel and wounding a further 620. Bush claims these weapons were provided by Quds, an elite branch of the Iranian military. He admits he has no idea whether the Iranian government is involved or not.

There are a few problems with this. First, the US is in no position to condemn other countries for meddling in the foreign affairs of Iraq. Second, the administration's credibility, like Saddam's weapons of mass destruction, is non-existent. Recently, the Pentagon's inspector general, Thomas Gimble, slammed Rumsfeld underling Douglas Feith for wilfully contorting intelligence about links between Iraq and al-Qaida in order to justify the Iraq war. Feith compiled a briefing that was "inappropriate" with conclusions that were "not fully supported by the available intelligence", concluded Gimble, who fell just short of branding Feith an outright liar.

But most importantly, the region's biggest obstacle to peace and stability is not Iran but the US. The invasion of Iraq has both bolstered Iran's standing by installing a friendly Shia regime in Baghdad, and given Iran every reason to arm itself for fear of imminent attack from US bases now embedded on its border. Each time the White House issues threats against Iran, it strengthens the crude, anti-semitic prime minister Mahmoud Ahmadinejad, who can rally the nation around a foreign enemy - a strategy with which Bush is all too familiar.

"We have to throw away the notion the US could not do it because it is too tied up in Iraq," says Colonel Sam Gardiner, a former US air force officer who has carried out war games with Iran as the target. "It is an air operation."

Like Keech before him, it seems once Bush has got hold of a bad idea he just can't let it go. Just because it is irresponsible, irrational, unpopular and unconscionable doesn't mean he won't do it.

"History does not repeat itself," Mark Twain once wrote. "But it does rhyme."



g.younge@theguardian.com