He's a heavyweight in al-Qaida but little known outside jihadi and intelligence circles even though he runs the terrorist movement's operations in a key front — Afghanistan — and may be linked to a plot in New York.
Mustafa al-Yazid makes no secret of his contempt for the United States, once calling it "the evil empire leading crusades against the Muslims."
"We have reached the point where we see no difference between the state and the American people," al-Yazid told Pakistan's Geo TV in a June 2008 interview. "The United States is a non-Muslim state bent on the destruction of Muslims."
Al-Yazid may also have links to Afghan immigrant Najibullah Zazi, whom U.S. authorities have arrested in an alleged plot to use homemade backpack bombs, perhaps on New York City's mass transit system.
Two U.S. intelligence officials, speaking on condition of anonymity because the case remains under investigation, told The Associated Press that the bespectacled, Egyptian-born al-Yazid used a middleman to contact Zazi, indicating that the al-Qaida leadership took a keen interest in what U.S. officials call one of the most serious terrorism threats crafted on U.S. soil since the Sept. 11, 2001, attacks.
History of extremist involvement
Despite his relative obscurity in the West, the shadowy, 55-year-old al-Yazid has been involved with Islamic extremist movements for nearly 30 years since he joined radical student groups led by fellow Egyptian Ayman al-Zawahri, now the No. 2 figure in al-Qaida after Osama bin Laden.
In the early 1980s, al-Yazid served three years in an Egyptian prison for purported links to the group responsible for the 1981 assassination of Egyptian President Anwar Sadat. After his release, al-Yazid, also known as Sheik Said and Abu Saeed al-Masri, turned up in Afghanistan, where, according to al-Qaida's propaganda wing Al-Sabah, he became a founding member of the terrorist group.
He later followed bin Laden to Sudan and back to Afghanistan, where he served as al-Qaida's chief financial officer, managing secret bank accounts in the Persian Gulf that were used to help finance the Sept. 11 attacks in New York and Washington.
After the U.S. and its allies invaded Afghanistan in 2001, al-Yazid went into hiding for years. He surfaced in May 2007 during a 45-minute interview posted on the Web by Al-Sabah, in which he was introduced as the "official in charge" of the terrorist movement's operations in Afghanistan.
Some security analysts believe the choice of al-Yazid as the Afghan chief may have signaled a new approach for al-Qaida in the country where it once reigned supreme.
Michael Scheuer, former head of the CIA unit that tracked bin Laden, believes that bin Laden and al-Zawahri wanted a trusted figure to handle Afghanistan "while they turn to other aspects of the jihad outside" the country.
Little experience in combat operations
Al-Yazid had little background in leading combat operations. But terrorism experts say his advantage was that he was close to Taliban leader Mullah Omar. As a fluent Pashto speaker known for impeccable manners, al-Yazid enjoyed better relations with the Afghans than many of the al-Qaida Arabs, whom the Afghans found arrogant and abrasive.
That suggested a conscious decision by al-Qaida to embed within the Taliban organization, helping the Afghan allies with expertise and training while at the same time putting an Afghan face on the war.
Close Taliban-al-Qaida ties
Al-Yazid himself alluded to such an approach in an interview this year with Al-Jazeera television's Islamabad correspondent Ahmad Zaidan. Al-Yazid said al-Qaida fighters were involved at every level with the Taliban.
"We participate with our brothers in the Islamic Emirate in all fields," al-Yazid said. "This had a big positive effect on the (Taliban) self-esteem in Afghanistan."
A September 2007 al-Qaida video sought to promote the notion of close Taliban-al-Qaida ties at a time when the Afghan insurgents were launching their comeback six years after their ouster from power in Kabul.
The video showed al-Yazid sitting with a senior Taliban commander in a field surrounded by trees as a jihad anthem played — rather than in a bleak desert hide-out. The Taliban commander vowed to "target the infidels in Afghanistan and outside Afghanistan" and to "focus our attacks, Allah willing, on the coalition forces in Afghanistan."
There is also evidence that al-Yazid has promoted ties with Islamic extremist groups in Central Asia and Pakistan, where other top al-Qaida figures are believed to be hiding.
"He definitely seems to have significant influence among the Pakistani Taliban and the Central Asian groups," terrorism expert Evan Kohlman said. "They regularly post and share his videos on the Web, just as they would with bin Laden or al-Zawahri."
In August 2008, Pakistani military officials claimed al-Yazid had been killed in fighting in the Bajaur tribal area along the Afghan border. However, he turned up in subsequent al-Qaida videos, all of which had clearly been made after the Bajaur fighting.
Al-Yazid appeared on an al-Qaida video posted this month, vowing to avenge the death of Pakistani Taliban leader Baitullah Mehsud, who was killed in a CIA missile strike Aug. 6.
"I say to the Islamic nation that even if we have lost Baitullah Mehsud, there are thousands of tribesmen who are like him and who will take revenge on the Americans and their allies," al-Yazid said.