What is al-Qaeda?
Al-Qaeda, Arabic for "the Base," is an international terrorist network founded by Osama Bin Laden in the late 1980s. It seeks to rid Muslim countries of what it sees as the profane influence of the West and replace their governments with fundamentalist Islamic regimes. After al-Qaeda's September 11, 2001, attacks, the United States launched a war in Afghanistan to destroy al-Qaeda's bases there and overthrow the Taliban, the country's Muslim fundamentalist rulers who harbored bin Laden and his followers. Like his predecessor George W. Bush, President Barack Obama has committed U.S. strategy to destroying al-Qaeda’s safe haven in the Afghanistan-Pakistan region, and limiting the group's ability to strike U.S. targets.

What are al-Qaeda's origins?
Al-Qaeda grew out of the Services Office, a clearinghouse for the international Muslim brigade opposed to the 1979 Soviet invasion of Afghanistan. In the 1980s, the Services Office--run by bin Laden and the Palestinian religious scholar Abdullah Assam--recruited, trained, and financed thousands of foreign mujahedeen, or holy warriors, from more than fifty countries. Bin Laden wanted these fighters to continue the "holy war" beyond Afghanistan. He formed al-Qaeda around 1988.

Where does al-Qaeda operate?
There is no single headquarters. From 1991 to 1996, al-Qaeda worked out of Pakistan along the Afghan border, or inside Pakistani cities. During the Taliban's reign al-Qaeda shifted its base of operations into Afghanistan. To escape the U.S.-led war in Afghanistan, al-Qaeda's leadership once again sought refuge in Pakistan's tribal areas after September 11, 2001. Analysts also believe bin Laden's group is training or has trained most of the terrorist groups in Pakistan's tribal areas; it has introduced its practice of suicide bombings to both the Afghan and the Pakistani Taliban, as well as affiliated groups in Iraq, Yemen, and North Africa.
One such bombing killed former Pakistani Prime Minister Benazir Bhutto in December 2007 at an election rally. But in Pakistan, at least, public sentiment for the group appears to be limited. In a poll PDF released in February 2008, Terror Free Tomorrow, a Washington-based nonprofit group, found that only 24 percent of Pakistanis had a favorable opinion of bin Laden in 2008 as compared to 46 percent in August 2007. Similarly, al-Qaeda's popularity dropped from 33 percent to 18 percent.

The Taliban was initially a mixture of mujahedeen who fought against the Soviet invasion in the 1980s, and a group of Pashtun tribesmen who spent time in Pakistani religious schools, or madrassas, and received assistance from Pakistan's Inter-Services Intelligence agency. The group's leaders practiced Wahhabism, an orthodox form of Sunni Islam similar to that practiced in Saudi Arabia. With the help of government defections, the Taliban emerged as a force in Afghan politics in 1994 in the midst of a civil war between forces in northern and southern Afghanistan.
They gained an initial territorial foothold in the southern city of Kandahar, and over the next two years expanded their influence through a mixture of force, negotiation, and payoffs. In 1996, the Taliban captured capital Kabul and took control of the national government. Taliban rule was characterized by a strict form of Islamic law, requiring women to wear head-to-toe veils, banning television, and jailing men whose beards were deemed too short. One act in particular, the destruction of the giant Buddha statues in Bamiyan, seemed to symbolize the intolerance of the regime. The feared Ministry for the Promotion of Virtue and Prevention of Vice authorized the use of force to uphold bans on un-Islamic activities.
The Taliban is not a monolith; it has various factions and includes people who join it for varied motives, ranging from global jihad to local grievances, say experts. Mohammed Omar, a cleric, or mullah, led the group during their rise to power. Omar is also a military leader, and he lost his right eye fighting the Soviets. From 1996 to 2001, he ruled Afghanistan with the title "Commander of the Faithful."
The Taliban movement remains loyal (PDF), to varying degrees, to Omar, writes Kenneth Katzman, a specialist in Middle Eastern affairs at the Congressional Research Service. Omar, and many of his top advisers, reportedly are based in the Pakistani city of Quetta, and are usually referred to as the Quetta Shura Taliban (QST).
U.S. and NATO forces have had success killing or capturing Taliban leaders since the start of the war. Mullah Omar's chief of security, Naqibullah Khan, was arrested in December 2004, and spokesman Latifullah Hakimi was apprehended ten months later. A U.S. airstrike in December 2006 killed Mullah Akhtar Usmani, a top commander. In May 2007, coalition forces killed the leader of the Taliban insurgency in the south, Mullah Dadullah, during an operation in Helmand Province.
And Mullah Ismail, a key Taliban figure in Kunar Province, was apprehended in April 2008. Even Afghan security forces have successfully targeted top Taliban leaders; in May 2009, Mullah Salam Noorzai was killed during a raid in Helmand Province. Mullah Abdul Ghani Baradar (NYT), commander of Taliban's military operations in Afghanistan, was captured in February 2010 in Karachi.

Where does Hamas operate?
Historically, Hamas has operated as an opposition group in Gaza, the West Bank, and inside Israel. Most of the population of Gaza and the West Bank is officially ruled by the Palestinian Authority government, so Hamas' new role as the legislature's controlling party has forced the group to reconsider the function and scope of its operations. Early on, some observers hoped that political legitimacy--and the accountability that comes with it--could wean Hamas away from violence. But to date, the group has refused to eschew violence and remains adamant about reversing the decision by its rival faction, the more secular Fatah movement, to recognize Israel's right to exist. In the summer of 2007, Hamas tensions with the Palestinian President Mahmoud Abbas, a Fatah man, came to a head and Hamas routed Fatah supporters, killing many and sending others fleeing to the West Bank. The result was a de facto geographic division of Palestinian-held territory, with Hamas holding sway in Gaza and Fatah maintaining the internationally recognized Palestinian Authority government in the West Bank town of Ramallah.
How big is Hamas?
Hamas' military wing is believed to have more than one thousand active members and thousands of supporters and sympathizers. On March 22, 2004, more than two hundred thousand Palestinians are estimated to have marched in Yassin's funeral. On April 18, 2004, a similar number publicly mourned the death of Rantisi.
Where does Hamas’s money come from?
Since its electoral victory to lead the PA, Hamas has had public funds at its disposal, though it does not have access to the foreign-aid dollars traditionally provided by the United States and European Union to the PA. Historically, much of Hamas's funding came from Palestinian expatriates and private donors in Saudi Arabia and other oil-rich Persian Gulf states. Iran also provides significant support, which some diplomats say could amount to $20 million to $30 million per year. In addition, some Muslim charities in the United States, Canada, and Western Europe funnel money into Hamas-backed social service groups. In December 2001, the Bush administration seized the assets of the Holy Land Foundation, the largest Muslim charity in the United States, on suspicions it was funding Hamas.
What attacks is Hamas responsible for?
Hamas is believed to have killed more than five hundred people in more than 350 separate terrorist attacks since 1993. Not all Hamas's attacks have been carried out by suicide bombers. The group has also accepted responsibility for assaults using mortars, short-range rockets, and small arms fire. In 1996, Hamas bombings played an important role in undermining the election hopes of Labor Party leader Shimon Peres, who represented the succession to assassinated Oslo Accords signatory, Yitzhak Rabin. (Likud's Benjamin Netanyahu, who ran against the accords, won instead). Between 2001 and 2003, in particular, Hamas and its comrades of Palestinian Islamic Jihad carried out dozens of such attacks, ultimately leading Israel to begin construction of a barrier between itself and Palestinian regions.
How does Hamas recruit and train suicide bombers?
The organization generally targets deeply religious young men--although some bombers have been older. The recruits do not fit the usual psychological profile of suicidal people, who are often desperate or clinically depressed. Hamas bombers often hold paying jobs, even in poverty-stricken Gaza. What they have in common, studies say, is an intense hatred of Israel.
Has Hamas always participated in the Palestinian electoral process?
No. Hamas boycotted the January 2005 PA presidential elections. But even prior to its 2006 victory in the PA's legislative elections, the group had made strong showings in municipal elections, especially in Gaza. In December 2004 West Bank local elections, Fatah won 135 seats and Hamas won seventy-five. In Gaza, where Hamas is based, it won seventy-seven out of 118 seats in ten council elections held in January 2005. Hamas appeared to have lost its political momentum in a September 2005 round of local elections in the West Bank: Fatah, benefiting from the Israeli withdrawal, took 54 percent of the vote over Hamas' 26 percent.