As a terrorism tool, the suicide bomber is a nearly perfect construct - simple, inexpensive and resoundingly effective. Thirty years ago, it was rare to see one; the suicide attack was pioneered by Lebanon's Hezbollah and Sri Lanka's Tamil Tigers. Now, in cities in Iraq, Pakistan and Afghanistan, bombers detonate themselves almost daily, putting civilians at risk.
Their motivations are difficult to fathom. Academics say they defy profiling. Suicide bombers may be rich or poor, educated or illiterate, fundamentalist or secular. Some want revenge for relatives slain in conflicts; others seek martyrdom. But the use of suicide bombers to advance political goals is growing, including disturbing trends such as the conscription of non-militants. Here are five broad categories.
Willing Jihadists
Most suicide bombers are young, adult and male - Sunni extremists who volunteer for the job. Often, they interpret religious texts as guaranteeing paradise for martyrs slain in battle. Some believe they will be doted on by 72 virgins in the afterlife. Also relevant, however, are Koranic passages about removing infidel foreign armies and their proxies from Muslim lands - the cited justification for most suicide attacks, including ones in Afghanistan, Pakistan and Iraq. Suicide bombings were unheard of in these countries a decade ago.
Examples: Umar Farouk Abdul Mutallab (the underwear bomber); the 9/11 hijackers.
Black Widows
Women, once a rarity in suicide attacks, are no longer uncommon. In Russia, where this week's subway attack took place, suicide bombings have come to be generally associated with women. They move easily through checkpoints, explosives tucked beneath flowing clothes. Often, they are relatives of men slain in conflicts, and occasionally they are pregnant. The wives of slain militants in Chechnya are known as "black widows" ( shakhidki). These women have participated in attacks ranging from the Dubrovka theatre siege in 2002 to the Beslan school siege in 2004.
Examples: Khava Barayeva (Chechnya, 2000); Wafa Idris (Israel, 2000); Sana'a Mehaidli (Lebanon, 1985 - believed to be the first female suicide bomber).
Children and Youth
Like women, children get far less scrutiny from security in conflict zones, so young males - boys, really - are signed up for attacks. In 2008, the Iraq military showed reporters six crying, captured youths, some as young as 14, who said they had been drafted by a "Saudi" insurgent to blow themselves up. A 2009 Washington Times investigation revealed that Pakistan's top Taliban leader was buying children as young as 7 for up to $14,000 to serve as suicide bombers.
Example: "Abdullah," a boy aged 11 or 12, arrested in Afghanistan wearing a suicide vest in 2009.
The Blackmailed
Some suicide bombers do not do the job willingly. Two years ago, a jailed Iraqi woman told The Associated Press that rape was used to first shame women and then cultivate them as suicide bombers as a means of restoring their honour. There are anecdotal accounts of similar techniques being used to recruit male suicide bombers in North Africa.
Example: Samira Ahmed Jassim, arrested in Iraq in January of last year, confessed to recruiting rape victims as suicide bombers.
The Unwitting
While it could be argued that suicide bombers are by nature irrational, many seem to fall short of being compos mentis. Body-packed bombs can be detonated remotely by terrorists who have duped an agent into wearing a vest, or are sometimes planted in a car. The Iraqis have used kidnap victims as bombers, blowing up their bomb-laden vehicles by remote control. In 2007, an Afghan pathologist told National Public Radio in the U.S. that 80 per cent of the remains of suicide bombers he examines indicate physical or mental disability.
Example: On election day in Iraq in January, 2005, police said insurgents used a disabled child for one of 38 separate suicide attacks on polling stations.
Colin Freeze covers terrorism and Shawna Richer is an editor at The Globe and Mail.
Colin Freeze