U.S. intelligence officials say only Osama bin Laden and his deputy Ayman al-Zawahiri are more important figures in the Al-Qaeda terrorist network.
U.S. President George W. Bush on yesterday applauded Pakistan for acting on what he called "solid intelligence" about al-Libbi's whereabouts.
"Al-Libbi was a top general for [Osama] bin Laden. He was a major facilitator and a chief planner for the Al-Qaeda network. His arrest removes a dangerous enemy who was a direct threat to America and for those who love freedom," Bush said.
U.S. Secretary of State Condoleezza Rice described al-Libbi as an Al-Qaeda 'field general" whose arrest is truly significant.
"This is somebody that we watched a lot every single day, those of us who have been very involved in the war on terrorism -- a very important figure for the Al-Qaeda network," Rice said.
But al-Libbi's exact role in Al-Qaeda remains unclear. U.S. intelligence officials believe he became third in command after Khalid Sheikh Mohammed -- the alleged mastermind of the September 11th terrorist attacks -- was captured in Rawalpindi near Islamabad in March of 2003.
Pakistani security officials say that since Mohammed's capture, al-Libbi had been the main contact between bin Laden and Islamic militants within Pakistan.
Pakistani President Pervez Musharraf has accused al-Libbi of involvement in two failed attempts on his life in December 2003.
Interior Minister Aftab Sherpao says al-Libbi also is a key suspect in several other bomb attacks in Pakistan -- including an attempt last year to kill Prime Minister Shaukat Aziz.
Islamabad also calls al-Libbi an accomplice of Amjad Hussain Farooqi -- an alleged Al-Qaeda militant from Pakistan who also was accused of planning the failed assassination attempts against Musharraf. Farooqi had been formally charged in the killing of "Wall Street Journal" reporter Daniel Pearl three years ago. He was killed in Karachi last September during a shoot-out with Pakistani forces.
Despite the details now emerging about al-Libbi and his links to bin Laden, he had been a relatively unknown figure in the Al-Qaeda hierarchy until last year, when Islamabad named him as one of the six most-wanted militants in Pakistan.
Born in 1965, he first traveled to Pakistan during the 1980s to fight in a U.S.-backed jihad, or holy war, against the Soviet occupation of Afghanistan.
He was helping to recruit Arab fighters for the cause when Osama bin Laden first arrived in the region. Al-Libbi is known to have joined with bin Laden in Sudan during the early 1990s.
Raul Bedi -- a correspondent for "Jane's Defense Weekly," who covers Afghanistan, Pakistan, and India -- notes that whenever there is an arrest of a senior Al-Qaeda leader -- particularly those who reportedly are close to bin Laden -- there is a surge of media speculation about the hunt for the top Al-Qaeda leader.
"I tend to agree with a lot of the experts that the hunt for Osama bin Laden is a completely different thing [than capturing al-Libbi]. Just because the Americans and the Pakistanis have managed to arrest a senior Al-Qaeda leader doesn't automatically mean that the trail has suddenly become hot to Osama bin Laden. I don't think the seizure of computer equipment or interrogations of people who have been captured is going to be a chain effect which is going to give them [actionable] information. Yes, intelligence is going to form part of a larger picture. But I don't think it is going to be precise intelligence which is going to allow anybody to launch any kind of a specific strike to capture senior Al-Qaeda leaders -- particularly Osama bin Laden," Bedi says.
Bedi says it is important to remember that Al-Qaeda is not a single terrorist organization, but rather, a network of many different terrorist groups.
"Al-Qaeda, after the attack by the Americans on Afghanistan, has split up into small units of three, four, five -- maybe 10 people at the very most. They are independent. They are arbitrary in their actions. And they are not controlled by any kind of multinational corporation structure where a chief executive officer gives a directive and the people down the chain follow it. So it is going to be extremely difficult. Every operation that either the Pakistani forces or the American forces launch is going to be based on individual intelligence on that particular [Al-Qaeda] group," Bedi says.
CIA veteran Gary Schroen also has doubts about the eminent capture of bin Laden. The 63-year-old Schroen was a member of one of the first teams of U.S. forces to arrive in Afghanistan after the terrorist attacks of 11 September 2001. A book he has written about the experience goes on sale next week.
Schroen says he is encouraged by the arrest of al-Libbi. But he says bin Laden is regarded almost as a "Robin Hood" figure among certain elements of the Islamic world. He says bin Laden's popularity is so great that Pakistan may not want to risk a potentially devastating political backlash by capturing him.
Schroen concludes that it is much easier for Islamabad to go after al-Libbi than bin Laden. He says that's because al-Libbi is a Libyan by name who has no standing within the conservative communities of Pakistan's autonomous tribal regions where he ultimately was captured.