What would possess a man to strap explosives onto his body, turning himself into a walking bomb? Or to steer a commercial aircraft filled with passengers into a building, causing untold death and destruction?
Suicide bombers claim they do it in the name of God.
But how legitimate is that claim?
The question is of vital importance to approximately 7 million Muslims living in the United States.
Although no one has claimed responsibility for Tuesday's terrorist attacks, authorities strongly suspect that it was carried out by supporters of
, the exiled Saudi living in Afghanistan. That information, combined with rising anger at the terrorist attacks, has resulted in a number of threats against Muslims and attacks on mosques and Muslim businesses.
But the notion of a Muslim waging jihad on the United States is an extreme, even distorted understanding of Islam, according to Muslim scholars and academics who study Islam.
"It hurts me that these people misunderstand religion and say that they represent our religion," says Imam Khalil Majdalawi, spiritual leader of the An-nur Mosque in Carney. "We believe in the Quran that Allah has sent [the prophet Muhammad] to be an emissary to all human beings, bringing them a message of mercy and a message of peace. If he has been sent like this, how do they understand that in his religion, there is something that is known as violence or extremism?"
As for suicide bombing, "There is no real Islamic basis for it," says John L. Esposito, director of the Center for Muslim-Christian Understanding at
University. "In Islam, the notion of suicide is as heinous or unacceptable as it's been historically in Catholicism."
But the beliefs of suicide bombers are rooted in passages of the Quran that scholars say are misinterpreted. The key concepts are jihad, which has often been translated as "holy war," and martyrdom, particularly the belief that martyrs immediately enter heaven.
The meaning of the Arabic word jihad is actually benign. It means to struggle or to strive.
"In whatever you expend effort, you are waging jihad," says Majdalawi. "If you are making effort in order to earn your living, this is called jihad. If you are spending effort in order to learn, this is called jihad. If you are teaching others the way to truth and good things, this is called jihad."
A person's internal struggle to do what is right, controlling one's base desires, is known as jihad akbar, or the greater jihad.
"It is the war in your own soul, against your own baser instincts, trying to cultivate the seed of moral authority so you become a moral force in human society," says Sulayman S. Nyang, a Howard University professor specializing in Islamic studies. "That is the greater jihad."
There is also a lesser jihad that involves a defense of Islam.
"Jihad also can take on a dimension that, in the struggle to be a good Muslim, there may be times where one will be called upon to defend one's faith and community. Then it can take on the meaning of armed struggle," Esposito says. "In Islam, this is a perfectly legitimate response to aggression."
Jihad in this context is the Islamic equivalent of the Christian theory of the "just war," the idea that although violence is evil, it may be used morally to overcome a greater evil, as long as it is used proportionately.
"With jihad, as with 'just war' in Christianity, the problem is when somebody takes the notion and distorts it and does not use in it in a defensive manner, but in an aggressive manner," Esposito says. "The question is legitimate versus illegitimate use of armed force or violence."
Indiscriminate killing of innocents would never be legitimate in the Quran, says Nyang of Howard University.
"Look at all the historical accounts of jihad, they were all waged as conventional war, not the invisible guerrilla tactics we see in modern times," he says. "Nor is jihad identified with any kind of indiscriminate killing of innocent people. There are strict rules of engagement."
Those rules of engagement include prohibitions against harming monks; violating women; killing the sick, weak or lame; and cutting down trees.
Closely linked with jihad as armed struggle is the concept of martyrdom.
"This notion of martyrdom is found very clearly in the Quran," says Charles Kimball, a Wake Forest University religious studies professor and the author of three books on Islam. "Those who die struggling in the way of God are promised immediate passage to paradise. No waiting until judgment at the end of time.
"The question is, who determines what martyrdom is, what is legitimate? This comes back to the question, can a suicide bomber be a martyr?" Kimball says. "The overwhelming number of Muslims would view this negatively. But there are people in Islam on the extremes who certainly have embraced this view. And who have been able to recruit others."
As some Muslims see it, the world would be better off if all embraced Islam, just as many Christians would like to see all become followers of Christ.
"From the beginning, Muslims have seen Islam as a civilizational system. It's not just a religion, it's a way of life," Kimball says. "There is this theme running through the Islamic world, including many who are not violent extremists, in the dream or ideal that somehow Islam can emerge from a difficult century and we can provide a way for an Islamic world civilization."
For the past three centuries, Kimball notes, most of the Muslim world has lived under the control of outside powers: the European colonialists and the superpowers. Now, the United States is the only world superpower, and for many Muslims, it represents the decadence of the West preventing emergence of a true Islamic society.
"That's the general notion someone like Osama bin Laden can build upon," Kimball says. "'We don't have to take it. We don't trust our leaders because they're corrupt, so we have to fight this war on whatever terms we can fight it.'"
But he warns that "you'd find a whole range of Muslims - even people who want an Islamic state, who don't agree with the United States - who wouldn't take that approach at all."
The American Muslim community quickly and unambiguously denounced Tuesday's attacks. Two hours after the first plane hit the World Trade Center, the American Muslim Political Coordination Council, an umbrella of four national Muslim groups, issued a statement saying: "We join with all Americans in calling for the swift apprehension and punishment of the perpetrators. No political cause could ever be assisted by such immoral acts."
Those who study Islam say it is important that Muslims not be demonized by the acts of a few terrorists. Muslims could be your neighbors, the point out, as they are on the verge of becoming the second-largest religious group in the United States.