(Yosri Fouda is the Chief Investigative Correspondent and Former London Bureau Chief for Al-Jazeera).

Though I would largely agree with Peter as to the importance of bin Laden's figure, I would not say that without him "9/11 would have been one of many harebrained schemes in the head of KSM." I would not even dare say that without KSM 9/11 would have been a distant dream surrounded by green birds in Ramzi Bin al Shibh's heart. Should we use this formula, I would find it in my heart to claim that without Atta 9/11 would probably have been just another Bojinka. It is my deep belief that the key to understanding not only 9/11 but also the future of Islamic terrorism is indeed Mohammed Atta.

From the perspective of the operation itself, neither bin Laden nor KSM knew of the crucial details in the last few weeks, including the zero hour (which Atta picked), until only five days prior. Any future team that includes a bin Laden and a KSM but does not include an Atta would not scare me as much as a team that includes an Atta without the two of them. This in my book is what renders talk about al Qaeda the organization versus al Qaeda the mindset slightly academic. Some symbolic figure out there will of course always be important, but some willing perfectionist on the ground is just crucial.

The "willing" quality is clearly far more common than the "perfectionist", but whenever they happen to combine in another Atta it will be another disaster waiting to happen. If then bin Laden was not there, he will find his own bin Laden, alive somewhere or on a screen or even dead in the books of Islamic history. And from a larger perspective, I find it difficult to comprehend how we can avoid, or at least be better prepared for, another disaster without seriously studying Atta's circumstances and motives.

-- Yosri Fouda

This week long terrorism salon will continue to be hosted by The Washington Note and UN Dispatch.