<The real question is: guilty or not guilty?

The short answer is: He said he did it.

The long answer is here.

For brevity, I'll skip to the chase:

Osama Bin Laden and the 11 September attacks



61. Nineteen men have been identified as the hijackers from the passenger lists of the four planes hijacked on 11 September 2001.

At least three of them have already been positively identified as associates of al-Qaeda.

One has been identified as playing key roles in both the East African embassy attacks and the USS Cole attack.

Investigations continue into the backgrounds of all the hijackers.

62. From intelligence sources, the following facts have been established subsequent to 11 September; for intelligence reasons, the names of associates, though known, are not given.

In the run-up to 11 September, bin Laden was mounting a concerted propaganda campaign amongst like-minded groups of people - including videos and documentation - justifying attacks on Jewish and American targets; and claiming that those who died in the course of them were carrying out God's work.

We have learned, subsequent to 11 September, that Bin Laden himself asserted shortly before 11 September that he was preparing a major attack on America.

In August and early September close associates of Bin Laden were warned to return to Afghanistan from other parts of the world by 10 September.

Immediately prior to 11 September some known associates of Bin Laden were naming the date for action as on or around 11 September.

Since 11 September we have learned that one of Bin Laden's closest and most senior associates was responsible for the detailed planning of the attacks.

There is evidence of a very specific nature relating to the guilt of Bin Laden and his associates that is too sensitive to release.

63. Osama Bin Laden remains in charge, and the mastermind, of al-Qaeda. In al-Qaeda, an operation on the scale of the 11 September attacks would have been approved by Osama Bin Laden himself.

64. The modus operandi of 11 September was entirely consistent with previous attacks.

Al Qaeda's record of atrocities is characterised by meticulous long term planning, a desire to inflict mass casualties, suicide bombers, and multiple simultaneous attacks.

65. The attacks of 11 September 2001 are entirely consistent with the scale and sophistication of the planning which went into the attacks on the East African Embassies and the USS Cole.

No warnings were given for these three attacks, just as there was none on 11 September.

66. Al-Qaeda operatives, in evidence given in the East African Embassy bomb trials, have described how the group spends years preparing for an attack.

They conduct repeated surveillance, patiently gather materials, and identify and vet operatives, who have the skills to participate in the attack and the willingness to die for their cause.

67. The operatives involved in the 11 September atrocities attended flight schools, used flight simulators to study the controls of larger aircraft and placed potential airports and routes under surveillance.

68. Al-Qaeda's attacks are characterised by total disregard for innocent lives, including Muslims.

In an interview after the East African bombings, Osama Bin Laden insisted that the need to attack the United States excused the killing of other innocent civilians, Muslim and non-Muslim alike.

69. No other organisation has both the motivation and the capability to carry out attacks like those of the 11 September - only the al-Qaeda network under Osama Bin Laden.

Conclusion

70. The attacks of the 11 September 2001 were planned and carried out by al-Qaeda, an organisation whose head is Osama Bin Laden.

That organisation has the will, and the resources, to execute further attacks of similar scale.

Both the United States and its close allies are targets for such attacks.

The attack could not have occurred without the alliance between the Taleban and Osama Bin Laden, which allowed Bin Laden to operate freely in Afghanistan, promoting, planning and executing terrorist activity.



Further material released later:

The attached document summarises both the public and newly declassified material linking Usama Bin Laden and the Al Qaida network to the terrorist atrocities of 11 September 2001. It updates the document published by the Prime Minister on 4 October.



The update has been produced to remind people why we are engaged in this action, and to publish new information:

-- There is now information linking the majority of the hijackers with Al Qaida, rather than just the three originally stated.

-- A senior Bin Laden associate has admitted since 4 October to have trained some of the hijackers in Afghanistan.

-- Bin Laden's own statements and those of his lieutenants since 4 October have also been increasingly self-incriminatory. He has made no attempt to deny responsibility for the attacks:

- On 7 October he said: "Here is America struck by God Almighty ...so that its greatest buildings are destroyed...I swear to God that America will not live in peace before peace reigns in Palestine, and before the army of the infidels depart the land of Mohammed".

- On 9 October one of his spokesmen praised the 11 September atrocities as "a good deed" which "transferred the battle into the US heartland". He warned "the storm of plane attacks will not abate".

- On 13 October, one of his associates broadcast direct threats referring back to 11 September: "we...advise the Muslims in the United States and Britain...not to travel by plane. We also advise them not to live in high-rise buildings and towers".

--Bin Laden has come closest to admitting responsibility in an inflammatory video made on 20 October which has been circulating among supporters of the Al Qaida network:

- Referring to the attacks on US buildings: "It is what we instigated for a while, in self-defence...So if avenging the killing of our people is terrorism, let history be a witness that we are terrorists".

- He also issued explicit threats: "Bush and Blair...don't understand any language but the language of force. Every time they kill us, we kill them, so the balance of terror is achieved".

- He pledged to continue the campaign of terror: "The battle has been moved inside America, and we shall continue until we win this battle, or die in the cause and meet our maker".

- He again admitted to terrorism: "The bad terror is what America and Israel are practising against our people...what we are practising is the good terror that will stop them doing what they are doing".

-- In an interview to the Pakistani paper Dawn in November 2001, he again made a number of self-incriminatory threats and statements.