‘The official story is a lie’, declared Tucker Carlson in his 2025 web series, The 9/11 Files. The former Fox News host turned tribune of the online right was late to the 9/11 conspiracy-theory party. In fact, he used to give such theories short shrift. In 2012, when he was confronted by a Twin Towers ‘truther’ with a camera, he let rip on the ‘parasites’ and ‘morons’ who peddle such lies. ‘In order to imply that there’s a conspiracy behind 9/11, you ought to have some evidence’, he said. ‘And you have none. So you should stop.’

Needless to say, the Carlson of 2026 has not heeded this advice. No new ‘evidence’ has ever been unearthed that contradicts the ‘official’ facts of that terrible day 25 years ago. Yet the conspiracy theories have shown no signs of stopping, spreading even to those who once considered themselves immune.

The ‘official’ facts are as follows. On 11 September 2001, Islamic extremists hijacked four commercial airplanes. They flew two into the World Trade Center, a third into the Pentagon and a fourth, believed to be heading for the White House or the Capitol, was mercifully diverted by its brave passengers before it crashed into a field. Within hours, US officials named the lead suspect as Osama bin Laden, the leader of al-Qaeda, who had previously orchestrated terror attacks in Yemen, Saudi Arabia, Kenya and Tanzania – and had even targeted the World Trade Center in New York with a truck bomb in 1993. In 2004, in a video statement broadcast on Al Jazeera, he claimed full responsibility for 9/11.

The fact that 9/11 had a clear perpetrator, with an extensive terrorist rap sheet and an obvious Islamist motive, has never been enough to assuage many people’s doubts about what ‘really’ happened. A poll ahead of the fifth anniversary of the attacks found that more than a third of Americans suspected that ‘federal officials assisted in the 9/11 terrorist attacks or took no action to stop them so the United States could go to war in the Middle East’. Fifteen years later, a study found that more than half of Americans believed ‘the government is concealing the truth about 9/11’. This is not to say that masses of Americans endorse the kookiest of the conspiracy theories on offer, but it does point to an alarming wellspring of doubt and distrust among the public.

The tiny number of Twin Towers survivors had not even been pulled from the rubble before the first conspiracy theories were advanced. On the day of the attacks, the notorious Alex Jones claimed he was ‘98 per cent’ certain the Bush administration was to blame. In fact, six weeks before 9/11, he devoted several hours of his Infowars show to a history of ‘false flag’ attacks before warning explicitly that President Bush was planning to commit an act of terror.

So far, so Alex Jones. Yet it would be a mistake to think that trutherism was merely the preserve of cranks and crackpots in dark corners of the internet. Perhaps the first mainstream figure to dip his toe into trutherism – or at least trutherism-lite – was literary giant Gore Vidal. In a 7,000-word essay, published in the Observer in 2002, Vidal accused the ‘Bush junta’ of setting out to deceive a ‘simple-minded’ public as a pretext for ‘our long-contemplated invasion and conquest of Afghanistan’. Bin Laden, Vidal claimed, was ‘chosen on aesthetic grounds to be the frightening logo’ for the war effort.

The truther movement kicked off in earnest in 2004 with the release of a statement from the group, 9/11 Truth. It called for an investigation into 9/11 and alleged that the Bush administration knowingly allowed the attacks to happen. It was signed by nearly 200 prominent figures, including activist lawyer Ralph Nader and Van Jones. Jones would go on to advise the Obama administration.

As the truther movement grew, a divide emerged that can be expressed through two acronyms: LIHOP (let it happen on purpose) and MIHOP (made it happen on purpose). Within each strand, people believe in a range of motives for the attack: to start wars, to make money, to smear Muslims or even to initiate a Satanic ritual.

Many truthers not only refuse to believe that the Twin Towers were brought down by jihadists – they also deny that planes were the cause of the destruction. ‘Jet fuel can’t melt steel beams’ became a common refrain. And so some other cockamamie explanation – that is, other than the jumbo jets crashing into them – must be found for the towers collapsing in the way they did.

One theory is that the Twin Towers were brought down by a controlled demolition. This is the premise of the film Loose Change, first released in 2005 and believed to have been watched by as many as 100million people. The ‘smoking gun’ for this claim is WTC7 (the ‘third tower’), which fell on 9/11 despite not being hit by a plane (it was actually destroyed by smouldering-hot debris from the Twin Towers collision).

The Iraq and Afghanistan wars that followed added further fuel to the conspiratorial fire. The Bush administration’s false claims about Saddam Hussein’s links to al-Qaeda and his weapons of mass destruction seemed to confirm, in the eyes of many, that we are ruled by liars. In the immediate aftermath of 9/11, 60 per cent of American voters said they trusted the federal government. This fell to less than a quarter by the end of Bush’s presidency in 2008.

Today, as Tucker Carlson’s embrace of 9/11 trutherism attests, conspiracy theorising about the attack on the Twin Towers is widespread. This speaks to a profound problem in the body politic. It is one thing to lose faith in an individual president or party, but it seems now as if vast swathes of the public have lost faith in politics in general. They routinely doubt the official narrative. This can do serious damage to democracy. While the conspiracy theorist may feel a fleeting sense of power, in having access to hitherto hidden knowledge, the belief that everything is controlled by a shadowy elite cabal is ultimately disempowering. If everything is rigged, then what’s the point of trying to change things through democracy, voting, organising or persuasion?

Darker still is the fact that conspiracy theories almost inevitably descend into anti-Semitism. After all, it is not a great leap to go from alleging a hidden elite controls world events to alleging the Jews control world events. And so it has been with 9/11. ‘A number of foreign governments may have had foreknowledge of 9/11’, claimed Tucker Carlson in The 9/11 Files, ‘but the Israeli government stands out in particular’.

Various theories assert that either Mossad, the Israeli intelligence agency, or Jewish officials in the Bush administration orchestrated the attack – or at the very least had prior knowledge that it was coming. And, of course, the ‘truth’ about this will never emerge because the Jews supposedly wrote the official 9/11 Commission report and control the government and the media. Some truthers even claim that no Jews died in 9/11 because the 4,000 Jewish employees at the World Trade Center were given advance notice of the attacks. In truth, at least 119 Jews perished in the Twin Towers.

Tragically, the anti-Semitic strain of 9/11 trutherism has only gained traction since the 7 October attacks on Israel – online and at protests. It’s not uncommon to see placards blaming the Jewish State for the 9/11 ‘false flag’.

In the 25 years since the towers fell, conspiracy theories that were once fringe and consumed as light entertainment have curdled into something far darker and more dangerous. The paranoia, anti-Semitism and swirling distrust of our democratic institutions unleashed in the wake of 9/11 must be confronted, before they fester any longer.