Early on, al-Qaeda was a close-knit band of extremists with common cause, with a centralized leadership, and a base from which to launch global operations.
With the death of Osama bin Laden, the loss of a host of top commanders, and its retreat from Afghanistan, al-Qaeda has become a diffuse group with no coherent center. But the emerging network of al-Qaeda offshoots, with operations around the world, is no less dangerous.
Call it al-Qaeda 2.0 - the evolution of a group whose directives once came from the top into a network of affiliates who are
essentially on their own to export a fundamentalist brand of Islam and upstage secular governments in the Muslim world.
Al-Qaeda's growing list of affiliates, by feeding off local grievances and exploiting political turmoil, are showing their strength in a number of countries, including Syria, Iraq, Libya, and Mali.
Their rise, which has come with little tutelage from what remains of the al-Qaeda brain trust in Pakistan, has sparked fears that they will continue to expand by exploiting local conflicts as battlegrounds for global jihad.
US Congressman Brad Sherman (California), the top Democrat at the House Foreign Affairs Subcommittee on Terrorism, Nonproliferation, and Trade, said during a hearing on July 18 that the evolved al-Qaeda remains a viable threat.
"Al-Qaeda has failed to carry out a major attack in the United States since 9/11," Sherman said. "However, the danger posed by al-Qaeda to the United States is still significant. al-Qaeda's structure has become more decentralized, less of an integrated corporation, and closer to a franchise. Its chief terrorist activities are now being conducted by its local and regional affiliates."
This week, hundreds of militants were back on the streets following coordinated, military-style attacks on prisons that were carried out by al-Qaeda's main affiliate in Iraq. The prison breakout was seen as a potential boost to al-Qaeda's fight in Syria.
Nowhere is al-Qaeda's evolution more apparent than in Syria, which has become the new battleground for extremist groups. Al-Qaeda's local affiliates have sided with Sunni rebels fighting against the regime of President Bashar al-Assad, a member of the Alawite Shi'ite sect, which Sunni extremists regard as heretical.
Shamila Chaudhary, a senior South Asia fellow at the New America Foundation in Washington, says the lawlessness in Syria has given al-Qaeda a new home and a base from which to carry out its activities. She says it is al-Qaeda's presence in conflicts such as Syria that still make it a potential threat to the region and the West.
"The real threat to a lot of countries now is what other pockets of vulnerability exist around the globe that could give al-Qaeda and its affiliates a home base. That creates new problems," Chaudhary says. "The Afghanistan-Pakistan environment was very much complicated by the fact that al-Qaeda was living there. Now that few of them are there, it becomes a much more regional and domestic conflict. That means [al-Qaeda] had to go somewhere else and that internationalizes conflicts because al-Qaeda threatens the UK, US and other countries."
In Pakistan, al-Qaeda has allied with extremist groups such as the Tehrik-e Taliban Pakistan (TTP), otherwise known as the Pakistani Taliban. The TTP, which is fighting to overthrow the Pakistani government and impose Sharia law, follows the hard-line, anti-Shi'ite Wahhabi brand of Islam advocated by al-Qaeda.
Groups like the TTP are not only helping extend al-Qaeda's presence and reach in their home countries, but also appear to be providing fighters for other theaters in which al-Qaeda has aligned itself with local affiliates.
TTP commanders recently claimed to have sent around 100 trained foot soldiers to fight alongside anti-Assad forces in Syria, and some TTP commanders have even claimed to have set up camps there. The Pakistani government, along with other TTP commanders, has rejected the claims.
Chaudhary says the group's claims appear to be part of a propaganda campaign to portray the TTP as an organization with global reach. But if their claims are legitimate, she says, the entrance of Pakistani fighters into the conflict would indicate al-Qaeda's growing presence in unstable, poorly governed countries in the region.
Fighters from 40 countries
Ibrahim Talib, head researcher and deputy director of the Center for Strategic Studies in Damascus, says there are more than 130,000 foreign jihadists currently fighting in Syria, with many having vowed allegiance to the al-Qaeda franchise.
"I can say with full confidence that there are more than 130,000 foreign and Arab terrorists who are fighting in Syria - I can fully confirm this number, which is huge and dangerous," Talib says. "Tunisians come first, with about 15,000 fighters, then Libyans, then Saudis, then Egyptians and Palestinians followed by Lebanese. After that comes the [fighters] from outside the region. There are more than 40 countries that have citizens fighting in Syria."
The increasing number of Sunni extremists among the opposition fighting in Syria has concerned secular rebels, who reportedly fear that al-Qaeda-linked militants are hijacking their local struggle against the government and making the country a hotbed of international terrorism.
That has led to infighting among the rebels. Groups like the Kurdish Democratic Union Party (PYD), a Syrian affiliate of the Kurdistan Workers Party (PKK), have engaged recently in fierce battles with al-Qaeda-linked rebels in northern Syria.
Salih Muslim, head of the PYD, says his troops have encountered Taliban fighters among the ranks of the extremist Sunni groups. "Extremist Islamist forces like al-Qaeda, the Al-Nusra Front, Ahrar Al-Sham, and other similar groups can go where they want and they can enter from any country they want," Muslim says.
"They come from Turkey, Iraq, and other places. They have been there for a long time and make up a large portion of the [main rebel group] the Syrian Free Army. The Syrian Free Army has denied it but the extremist groups fight under their name. These groups are everywhere."
RFE/RL's Radio Free Iraq correspondent Abdul Hameed Zebari in Damascus, and RFE/RL correspondents Heather Maher and Richard Solash in Washington contributed to this report