With Osama bin Laden and his chief lieutenants dead, captured or on the run, al Qaeda's operations are being directed by a handful of combat-hardened veterans, most of them little-known Middle Eastern men who built their terrorist resumes together mounting lethal attacks against the USS Cole and U.S. embassies in eastern Africa.

U.S. and European intelligence sources identified six emerging leaders as key to running the terrorist network's global military and financial networks. Some members of this group have come to the fore in recent months; others were already known to intelligence organizations. Intelligence officials view these men's emerging roles within al Qaeda as proof that the group can adapt to rapidly changing circumstances and regenerate its leadership.

The new leaders "have been there from the beginning, but were in the shadows, not the most visible people," said a European intelligence analyst. "But they have their skills, and in war you need your best commanders."

The nucleus of the group has worked together for years. Some of the six crossed paths while training Somali militiamen who killed 18 U.S. Army Rangers during a firefight in Mogadishu in October 1993, setting up the 1998 bombings of the U.S. embassies in Tanzania and Kenya, and plotting the October 2000 suicide ramming of the USS Cole in a port in Yemen.

But the overall network is becoming increasingly decentralized. While the al Qaeda leadership prior to Sept. 11, 2001 had a ruling council, called a shura, which vetted plans and made major financial decisions, the new leaders are less able to communicate and are spread around Afghanistan, Pakistan, the Arabian Peninsula and Southeast Asia, intelligence officials said.

"The strength of the group is they don't need centralized command and control," said one U.S. intelligence official. They "know what it is they want to do."

While Ayman Zawahiri, bin Laden's longtime top aide, is still viewed as al Qaeda's official deputy commander, his months on the run appear to have made it difficult or impossible to exercise operational control over troops on the ground.

In addition, Saad bin Laden, who was being groomed to succeed his father, is believed to be likewise on the run. In his early twenties, he is also considered too inexperienced to assume operational control of the organization. Based on an analysis of the breathing and speaking patterns Osama bin Laden exhibited in a videotape released in December, Western intelligence officers believe he had suffered a severe chest wound but survived a U.S. air and ground assault in eastern Afghanistan.

The new leaders, in contrast, are believed to have orchestrated a wave of recent terrorist plots against Western targets. The Oct. 12 bomb attack of a Bali nightclub district, which killed 180, most of them tourists, has focused world attention on an entrenched regional terrorist network in Southeast Asia and its links to al Qaeda through an Indonesian militant, Riduan Isamuddin, known to followers as Hambali.

Other recent plots attributed to al Qaeda include the April 11 bombing of a Tunisian synagogue that killed 21 people, including 11 German tourists; the foiled suicide assaults on U.S. and British warships in the Strait of Gibraltar, and an elaborate scheme earlier this year to blow up the U.S., British, Australian and Israeli embassies in Singapore.

Al Qaeda's military operations have moved out of Afghanistan to the Middle East, Southeast Asia and around the world, said Rohan Gunaratna, a terrorism expert at the University of St. Andrews in Scotland. "Al Qaeda will become even more fractured and will rely increasingly on local and regional groups" to carry out attacks, he said.

The organization's financial structure is also rapidly decentralizing, according to a senior U.S. official. "There is no central banker for al Qaeda anymore," the official said, adding that intelligence officials believe bin Laden, as he fled his Afghanistan stronghold, told his people "to go out, raise your own money, carry out your own attacks, and you have my blessing for whatever you do. You don't need approval from headquarters anymore."

With the decentralization has come increased difficulties for intelligence officials tracking the terrorists' moves. The new leaders have carefully hidden their identities behind a maze of aliases. Learning such basic information as their real names, birth dates and nationalities has often proved problematic.

Intelligence analysts said several new leaders came up through the ranks of the Egyptian Islamic Jihad, the organization led by Zawahiri until he merged it with al Qaeda in 1998. The analysts said that a long internal power struggle within al Qaeda between Egyptian and Yemeni factions appears to have been won by the Egyptians, based on the contours of the new leadership.

Until recently, Western intelligence officials had identified Khalid Sheik Mohammed, a Kuwaiti of Palestinian origin who allegedly played a key role in planning the attacks of Sept. 11, 2001, as the most important emerging leader. His background includes involvement in the 1993 World Trade Center bombing and a foiled 1995 plot to crash a dozen U.S. airliners into the Pacific, as well as the Tunisia synagogue bombing in April.

But last month, his associate, Ramzi Binalshibh, a key aide to the Sept. 11 hijackers, was captured in Pakistan after he and Mohammed took part in an interview broadcast on the al-Jazeera satellite television network. Binalshibh, now in U.S. custody, is being questioned at an undisclosed location, and Mohammed is believed to be more consumed with avoiding capture than with running operations.

With Mohammed's status uncertain, intelligence officials have focused on six other emerging al Qaeda leaders. The following descriptions are based on interviews with U.S. and European intelligence analysts, U.S. law enforcement officials and terrorism experts.

Saif al-Adel: An Egyptian and a member of al Qaeda's "security committee" for several years, he is viewed as the new military leader for the remnants of al Qaeda and the Taliban in the Afghanistan-Pakistan border region. He took over as chief of military operations late last year, after U.S. bombs killed Muhammad Atef, al Qaeda's military commander.

Described by one European expert as "a military man, prepared to take command," he was a special forces officer in the Egyptian army before he fled to Saudi Arabia. He then traveled to Pakistan in 1988 to join the mujaheddin rebels fighting against Soviet occupation in Afghanistan.

A member of al Qaeda since its founding in the early 1990s, he was trained by the Lebanese guerrilla group Hezbollah. Al-Adel is believed to be a key figure in a tactical alliance between al Qaeda and Hezbollah, cutting across the traditional divide between the Shiite Muslims in Lebanon and the Sunni Muslims that make up al Qaeda.

He has planned or participated in some of al Qaeda's most deadly attacks. Al-Adel trained and fought alongside Somalis who ambushed the U.S. Army Rangers in Mogadishu. He helped plan the 1998 attacks on the U.S. embassies in Africa, and he was a key coordinator of the attack on the USS Cole.

Al-Adel left Afghanistan in November or December and traveled to Europe, returning to Afghanistan in January to lead some of the fighting against U.S. troops during Operation Anaconda in March, when U.S. forces swept through mountains in eastern Afghanistan. During those battles, which raged for more than a week, al-Adel faxed his accounts of the fighting to the Pakistani press.

He was hiding in Iran this summer, but has since moved back to the Afghanistan-Pakistan border area to coordinate strikes against U.S. and allied forces.

Abdullah Ahmed Abdullah: Another Egyptian, he has become al Qaeda's chief financial officer, at least in Pakistan and Afghanistan. Abdullah, about 40 years old, joined the Egyptian Islamic Jihad and traveled to Afghanistan in the late 1980s. He was among the 480 Arab combatants who joined bin Laden when he moved to Sudan in 1991.

From Sudan, Abdullah traveled to Somalia for a time. In 1998 he moved to Kenya, where he arranged and paid for the travel of the al Qaeda operatives who planned the Aug. 7 bombings of the U.S. embassies in Africa.. He left Nairobi on Aug. 6 and went to Karachi, Pakistan.

The following month, Abdullah traveled to Monrovia, Liberia, to buy diamonds on behalf of al Qaeda. The deal, set up to buy diamonds mined by rebels of the Revolutionary United Front in neighboring Sierra Leone, opened a new way for al Qaeda to hide its financial assets. The soft-spoken fighter, married with four children, is believed to be in the tribal areas of Pakistan or in Afghanistan.

Abu Musab Zarqawi: A Jordanian, Zarqawi has traveled extensively in the Arab world since the Sept. 11, 2001 attacks, including going to Baghdad for medical treatment after losing a leg.

Zarqawi has also traveled to Iran, Syria and Lebanon during the past year and is trained in the use of poisons and toxins. In early July, he took a poisonous substance disguised as an ointment into Turkey, but the purpose was unclear. "He is their highly mobile top operator and facilitator," a European source said.

Little is known about his path in al Qaeda. German officials in May identified him as the leader of Al Tawid, a radical Palestinian group that was identified as a branch or subgroup of al Qaeda. He was sentenced to death in absentia in Jordan for plotting to blow up a luxury hotel in Amman in January 2000, part of a millennium bombing plot.

Riduan Isamuddin: An Indonesian known as Hambali, he is al Qaeda's liaison to loose-knit radical Islamic groups in Southeast Asia -- and one non-Arab who seems to have been given authority to make independent decisions. "Hambali is a regional leader in Southeast Asia," said a U.S. official. "He's a really skilled operator, one of the really capable ones."

A veteran of the wars in Afghanistan, Isamuddin is believed to have plotted the recent, foiled attempts to attack the embassies of the United States, Israel, Britain and Australia in Singapore.

He was a founder of a company called Konsojaya, which police in the Philippines believe served as a financing arm for terror activities, including the failed 1995 airliner plot.

Tawfiq bin Atash: Known as Khallad, Atash is either Saudi or Yemeni, and is believed to have lost a leg in combat in Afghanistan. He may now be in Pakistan. In recent months he served as a trainer, along with Binalshibh, of the group that plotted suicide attacks in the Strait of Gibraltar.

"This is a major-league killer who orchestrated the Cole attack and possibly the Africa bombings," wrote a CIA officer two months before the Sept. 11 attacks.

In the days after Sept. 11, U.S. officials bolstered their charges that the hijackers were linked to bin Laden and al Qaeda by publicizing the presence of two of the hijackers at a Malaysia meeting with Atash in January 2000.

Rahim al-Nashri: A Yemeni often called al-Makki, he is described as Atash's "handler" within al Qaeda for the Cole attack. He is now in Yemen, U.S. officials said, under the protection of tribesmen there.

Al-Nashri was an owner of Al Mur Honey in Yemen, a company the United States has branded a terrorist financier. He was detained in Saudi Arabia in 1998 and deported the following year. He is believed to have been involved in the failed Strait of Gibraltar plot.

"It would be much easier if we had a more centralized structure to aim at, like al Qaeda was in Afghanistan," said a senior U.S. official. "Now, instead of a large, fixed target we have little moving targets all over the world, all armed and all dangerous. It is a much more difficult war to fight this way."