Ayman al-Zawahiri: Al Qaeda No. 2

March 18, 2004 — -- Al Qaeda leader Dr. Ayman al-Zawahiri, Osama bin Laden's top lieutenant, may be the most influential member of al Qaeda.

The Egyptian surgeon has been called one of the masterminds behind the vast al Qaeda network and a likely successor to bin Laden. And as former head of Egyptian Islamic Jihad, he has a long history of terror-related crimes.

Recent intelligence reports indicate Zawahiri and bin Laden have moved out of Pakistan, crossing the mountainous border back into Afghanistan.

Those reports have came as Arabic television stations aired audiotapes purportedly made by Zawahiri. In one of the tapes, a man thought to be Zawahiri taunted President Bush and threatened new attacks on the United States.

"Bush," said the voice believed to be Zawahiri's, "fortify your targets, tighten your defense, intensify your security measure because the fighting Islamic community, which sent you New York and Washington battalions, has decided to send you one battalion after the other, carrying death and seeking heaven."

Interpol issued a top-level arrest warrant for Zawahiri shortly after the terror attacks of Sept. 11, 2001, yet his whereabouts have long been unknown. The list of terrorist attacks tied to al-Zawahiri is long: