Bush releases bin Laden's 'smoking gun' video

Its contents had been massively trailed. The quality of the sound and the fuzziness of the pictures were those of a poor home video. But the impact of the Osama bin Laden videotape released here yesterday was even more devastating – and the apparent self-incrimination even more staggering – than almost anyone had expected.

After days of hesitation, the Pentagon finally unveiled the Bush administration's 'smoking gun," demonstrating beyond any reasonable doubt that the Saudi-born fugitive was responsible for the 11 September attacks on the World Trade Centre and the Pentagon.

The most damning section was when Mr bin Laden, smiling softly and gently gesturing, explains to his dinner companions how "we calculated in advance the number of casualties from the enemy based on the position of the tower". His expectation was that "three or four" floors only would be hit. But, Mr bin Laden went on, he was "the most optimistic of them all, due to my experience in this field" – a reference to his training in the family construction business.

He said: "I was thinking that the fire from the gas [fuel] in the plane would melt the iron structure of the building and collapse the area where the plane hit and the floors above it only. That is all we had hoped for."

Unless this is a boast of quite astounding invention – or the video is a total concoction – these words would settle any doubt that Mr bin Laden's al-Qa'ida was behind the attacks.

They were delivered with a smug, almost languid, matter-of-factness that only adds to the chilling effect. Later Mr bin Laden, dressed in his familiar combat jacket over white robes, spoke of how "the brothers who heard the news were overjoyed" and how the events "benefited Islam greatly". The video, whose existence had been hinted at by Tony Blair and whose contents were partially leaked to The Washington Post at the weekend was apparently found in late November at a house in Jalalabad.

It runs for an hour and has three parts: an original taping of a visit by other people to the US helicopter downed in Ghazni province in October, followed by two segments chronicling what the Pentagon called a "courtesy visit" by Mr bin Laden and his entourage to an unidentified sheikh, apparently crippled from the waist down.

These exchanges are believed to have taken place earlier in November, probably a few days before the start of the Muslim holy month of Ramadan, possibly in Kandahar.

In a statement accompanying the release, the Pentagon said it had only gone ahead "after balancing concerns about any additional pain that could be caused against the value of having the world fully appreciate what we are up against in the war against terrorism."

Americans, of course, have long appreciated that, even though the sense of renewed outrage here was palpable. "Get him and kill him" was how the reaction on American streets might be summed up. "It removes all doubt who was responsible," said Donald Rumsfeld, the US Defense Secretary, adding that Mr bin Laden believed that the fugitive was still inside Afghanistan, despite reports that he had escaped into Pakistan.

The real intended audience is the Muslim world, where anti-Americanism is rife. The Bush administration hopes the exotic conspiracy theories that circulate there, among them allegations that these attacks were part of a Zionist plot, will be banished once and for all by the evidence of the videotape.

For that reason, the Pentagon called in four outside translators to avoid any charges that the English-language version had been manipulated to enhance Mr bin Laden's guilt. Final approval for the release was given by President Bush.

The decision has led to charges of hypocrisy after the White House pressed US networks not to show TV footage of Mr bin Laden calling on the Muslim world to exact vengeance on America for its war in Afghanistan.

Mr bin Laden recounts how he had been told the previous Thursday that the attacks would take place on 11 September and how he had heard of the jets smashing into the World Trade Centre on the radio, followed by effusive congratulations from the sheikh. Another supporter, Abu Gaith, who spoke of the attack being greeted with joy, like "when there is a soccer game and your team wins". Later, Mr bin Laden says Muhamed Atta "from the Egyptian family" – which the Pentagon says means al-Qa'ida's Egyptian group – was in charge of the hijackers.

Mr bin Laden calls Atta "a pious man" who "became a martyr". He then described the plot: "The brothers who conducted the operation" only knew they were in a "martyrdom operation ... we did not reveal the operation to them until they are there and just before they boarded the planes. Those who were trained to fly didn't know the others."