One can ask, at this point, whether 9/11 or some similar tragedy might have happened without bin Laden to steer it. The answer is certainly not. Indeed, the tectonic plates of history were shifting, promoting a period of conflict between the West and the Arab Muslim world; however, the charisma and vision of a few individuals shaped the nature of this contest. The international Salafist uprising might have occurred without the writings of Sayyid Qutb or Abdullah Azzam’s call to jihad, but al-Qaeda would not have existed. Al-Qaeda depended on a unique conjunction of personalities, in particular the Egyptians—Zawahiri, Abu Ubaydah, Saif al-Adl, and Abu Hafs—each of whom manifested the thoughts of Qutb, their intellectual father. But without bin Laden, the Egyptians were only al-Jihad. Their goals were parochial. At a time when there were many Islamist movements, all of them concentrated on nationalist goals, it was bin Laden’s vision to create an international jihad corps. It was his leadership that held together an organization that had been bankrupted and thrown into exile. It was bin Laden’s tenacity that made him deaf to the moral quarrels that attended the murder of so many and indifferent to the repeated failures that would have destroyed most men’s dreams. All of these were qualities that one can ascribe to a cult leader or a madman. But there was also artistry involved, not only to achieve the spectacular effect but also to enlist the imagination of the men whose lives bin Laden required.
Wright, Lawrence. The Looming Tower: Al-Qaeda and the Road to 9/11. Vintage Books, 2007, 2011. p. 375