Public Enemy No. 2

In retrospect, it was a mistake to chase the two men out of Sudan. In the mountains and caves of Afghanistan, they were newly safe from prying eyes. In 1998 came the attacks on the U.S. embassies in East Africa, for which al-Zawahiri, like bin Laden, was later indicted in New York City. That attack also set off a U.S.-led manhunt throughout the world in which dozens of members of Al Jihad were arrested and extradited to Egypt, further crippling the organization's infrastructure. The besieged group split into two factions. One side angrily denounced al-Zawahiri for dragging members into a needless battle with the U.S. The other loyally followed him into a deeper alliance with bin Laden.

Largely because of al-Zawahiri, the ranks of al-Qaeda are full of Egyptians, a development resented by some of bin Laden's old Saudi confederates. Early on, al-Zawahiri also installed at bin Laden's side his own faithful lieutenant, Mohamed Atef, who serves bin Laden as both a military commander and personal security chief. Al-Zawahiri has with him in Afghanistan his wife and their children. He has told an interviewer that they understand their stay there to be similar to the Prophet Muhammad's Hegira, or migration from Mecca to Medina.

In recent weeks al-Qaeda operatives have been looking around for an Islamic publisher for a manuscript titled Cavaliers Under the Prophet's Banner. The book is said to be a mission statement that al-Zawahiri completed just before Sept. 11. The physician turned terrorist seems determined to leave his testament and inspirational manual, shaped by Qutb's work, to future generations. Ayman al-Zawahiri has never been one to think small.