BRUSSELS, Belgium (AP) _ The United States gave its NATO allies clear evidence Tuesday that ``conclusively'' links Osama bin Laden and his al-Qaida network to the Sept. 11 terror attacks, NATO's secretary-general said.
In response, the alliance dropped the only condition on invoking Article 5 of its charter, which states that an attack on one member is an attack on all, Secretary-General Lord Robertson said.
``We don't intend at the moment to discuss how NATO will translate this decision into operational action,'' Robertson said. ``The United States are still developing their thinking and they will come back to the alliance in due course when that thinking is crystallized.''
NATO allies last month agreed to invoke Article 5 if Washington could show that the attacks on the World Trade Center and the Pentagon were directed from abroad.
Tuesday's classified briefing had demonstrated that, and Article 5 was now ``fully invoked,'' Robertson said.
NATO officials said that means each member state is morally bound to help the United States if asked.
``The United States of America can rely on the full support of its 18 NATO allies in the campaign against international terrorism,'' Robertson said.
Robertson refused to elaborate on the ``additional information'' provided by U.S. Ambassador at Large Francis X. Taylor, who is President Bush's coordinator for counterterrorism.
The NATO secretary-general said it must remain secret for now ``for obvious reasons.''
He said the briefing covered the attacks themselves, the results of the investigation so far, what is known about bin Laden and al-Qaida, ``their involvement in the attacks and in previous terrorist activity, and the links between al-Qaida and the Taliban regime in Afghanistan.''
The United States was also briefing its allies directly in their capitals, Robertson said. In Pakistan, which neighbors Afghanistan and has promised to cooperate with the United States against bin Laden, the U.S. ambassador briefed the president, Gen. Pervez Musharraf, on the status of the U.S. investigation of bin Laden.
In the Belgian capital, where the NATO session was held, Russian President Vladimir Putin was meeting EU leaders Tuesday, and was to see Robertson on Wednesday. Putin has thrown his support behind the American-led anti-terrorist coalition, drawing his country into closer cooperation with the West.
``The facts are clear and compelling,'' Robertson said of the U.S. briefing. ``The information presented points conclusively to an al-Qaida role.''
``We know that the individuals who carried out these attacks were part of the worldwide terrorist network al-Qaida headed by Osama bin Laden and his key lieutenants and protected by the Taliban,'' he said. ``It is clear that all roads lead to al-Qaida and pinpoint Osama bin Laden as having been involved in it.''
Robertson's comments came ahead of a speech by British Prime Minister Tony Blair, who warned Afghanistan's Taliban rulers that they must ``surrender terrorists or surrender power.''
The Taliban, an Islamic militia that controls the majority of Afghanistan, said Sunday they know where bin Laden is, and that he is under their control. Previously, they had said they didn't know the Saudi millionaire's location, but they could deliver messages to him.