The organizers said they began their planning two months ago, long before the recent disclosures about intelligence lapses.

Still, today's disclosures provide the most detailed official description of intelligence lapses.

While other studies of American intelligence lapses have been ordered by past administrations, none has taken place at the level of a presidential commission.

"There were intelligence lapses on our part, and we admit to them," the official said, according to the journalists who attended the meeting.

Some lawmakers had pushed for hearings into any intelligence lapses to be held last year.

Were they moved in surreptitiously, or is it an intelligence lapse?

The impasse is a revealing example of how sensitive the issue of intelligence lapses before Sept. 11 remains for the administration.

An independent investigation of intelligence lapses before the attacks might provide the necessary heat for reform.

Mr. Graham said he did not want to get ahead of his own inquiry in making a final determination about any intelligence lapses.

As the story continues, footnotes will link specific intelligence lapses, warnings, or lost opportunities to this timeline.