Nato said yesterday the US had provided "clear and compelling" evidence linking the terrorists who attacked America both with Osama bin Laden's al-Qa'ida network and the Taliban regime in Afghanistan.
After a 40-minute intelligence report at Nato headquarters in Brussels, the alliance declared itself satisfied that the attacks came from abroad – the only condition needed to activate its Article 5 collective security agreement.
It remained unclear what use, if any, the US will make of Nato's offer of support. But the briefing increased the international pressure on the Taliban by demonstrating that the US is confident enough of its case against Afghanistan to outline it to its allies. Whether its claims would stand up in a court of law remains doubtful, however. The evidence, presented by Frank Taylor, the US State Department's co-ordinator for counter-terrorism, was described by one source as powerful and convincing but circumstantial.
The Russian President, Vladimir Putin, meanwhile, told a news conference during a visit to Belgium: "Russia's special services do not need any additional proof to participate in the struggle against terror acts", as he gave strong support to the US-led coalition.
The alliance's ambassadors were given no direct documentation or intercepted communication proving that Mr bin Laden ordered the attacks. As one source put it: "This is not the type of briefing where they come with a copy of a bank transfer or a ticket invoice." Instead, Mr Taylor reconstructed the events of 11 September and the efforts of the massive FBI investigation to link those who took part in the terrorist attack, through their contacts, to the al-Qa'ida network and to the Taliban.
After the classified briefing, the Nato secretary general, Lord Robertson of Port Ellen, said: "It is clear that all roads lead to al-Qa'ida and pinpoint Osama bin Laden as being involved ... The facts are clear and compelling. The information presented points conclusively to an al-Qa'ida role in the 11 September attacks. We know that the individuals who carried out these attacks were part of the worldwide terrorist network of al-Qa'ida, headed by Osama bin Laden and his key lieutenants and protected by the Taliban."
Nato invoked the Article 5 mutual defence clause of its 1949 founding treaty for the first time in its history on 12 September, but made it conditional on proof that the assault was initiated from abroad. Lord Robertson said that "if" had now been removed.
The decision may be of more symbolic than military importance. Yesterday's US briefing, given with short notice from the US side, was welcomed by the Nato allies, some of whom had complained privately about being sidelined at a meeting of defence ministers last week.
Then, the Deputy US Defence Secretary, Paul Wolfowitz, gave only a very general presentation to his Nato counterparts and was less informative than at a later meeting with the Russian Defence Minister, Sergei Ivanov.
The American ambassador to Pakistan, Wendy Chamberlin, had a 90-minute meeting yesterday with the country's President, General Pervez Musharraf, but a government spokesman said later that no evidence connecting Mr bin Laden or al-Qa'ida to the attacks had been handed over.
"The meeting was simply to inform the President about the state of the investigation," said a Foreign Ministry spokesman, Riaz Mohammad Khan. "We have yet to receive any detailed evidence with regard to the persons responsible for the horrendous acts of 11 September and their linkages with al-Qa'ida or Osama bin Laden"
Told that the US had provided "conclusive" evidence yesterday to Nato, Mr Khan said America had a special relationship with the organisation, of which Pakistan was a member. He added: "Once the US has some kind of concrete evidence, we hope that it will be shared with us."
Washington may be reluctant to do so, however, given Pakistan's continuing relationship with Afghanistan's Taliban regime. It is the only state that still recognises the Taliban and the US is likely to fear that anything it reveals to the Pakistani government might be passed on by Taliban sympathisers.
According to reports yesterday, Mr Bin Laden telephoned his adoptive mother two days before the terror attacks and told her to watch out for "big news" and that she should not expect to hear from him for a long period because he would be going underground.
The communication, apparently intercepted by intelligence services, was made to Al Kalifa bin Laden, one of four wives of Mr bin Laden' father, a Saudi construction magnate.
Al Kalifa bin Laden, who is Syrian, keeps an apartment in Paris. She is believed to have checked into an American hospital in the French capital for treatment for cancer. Some reports said she received the call while visiting Damascus.
Diplomats in Brussels still expect the military riposte, when it comes, to be dominated by the US with a small contribution from some other allies such as Britain and France. But now that the way forward has been cleared over Article 5, Nato will examine what it can offer.
Yesterday also saw two further moves in the efforts to cut off the source of funding to terrorist organisations. After unusually swift negotiations, the European Parliament agreed to a compromise which will speed through a long-awaited European directive to combat money-laundering.
Meanwhile, the European Commission proposed that the 15 EU member states freeze all funds held by 27 organisations and individuals suspected of supporting and financing terrorist activities.
Today, the international efforts to fight terrorism will be taken a step further when President Putin meets Lord Robertson and the European Commission president, Romano Prodi, in Brussels.Reuse content