From the 9/11 hijackers to the double agent whose suicide attack in Afghanistan killed seven CIA employees last December, many people want to know what drives some Muslims – many of whom are middle class and well educated – to kill themselves in attacks on Americans and others in the West.
After examining 2,200 suicide attacks around the world since 1980 – the most comprehensive analysis ever conducted – I've concluded that the answer is both simple and disturbing. What drives them is deep anger at the presence of Western combat forces in the Persian Gulf region and other predominately Muslim lands.
Popular accounts of these suicide terrorists give the impression that most of them are globe-trotting extremists radicalized by militant networks to strike outside their homeland for religious or other transnational causes. These accounts are false.
What the evidence shows
In the 2,200 suicide attacks since 1980, over 90 percent of the attackers carried out strikes in their home countries, often just miles from their homes, to resist foreign occupation of land they prize.
Hence, Lebanese carried out the suicide attacks against Israel's occupation of Lebanon; Turkish Kurds carried out the suicide attacks by the Kurdistan Workers' Party against the Turkish military presence in their home areas; and Iraqis, Saudis, Syrians, Kuwaitis, and Jordanians carried out the suicide attacks against America's military occupation of Iraq and the US threat to countries adjacent to Iraq.
Afghanistan is a prime example. We can identify 93 suicide attackers who have killed themselves to strike targets, mostly US and Western troops, in Afghanistan in recent years.
More than 90 percent are Afghan nationals and another 5 percent are from border regions of the country, while only 5 percent are from areas of the world beyond the immediate zone of conflict.
In other words, suicide terrorism in Afghanistan is not part of some global jihad looking for a place to land, but regional opposition to foreign military presence.
We're missing the real threat
Transnational suicide terrorists do exist. But, they are exceptions to the rule. Understanding that transnational suicide attackers are "black swans" has important implications for explaining their existence. For years, many have sought to explain how an individual becomes a transnational terrorist by seeking to track points along a spectrum of radicalization.
The basic idea is that there is a large pool of potential extremists who become progressively radicalized either through elite manipulation (religious leaders in mosques) or through social and economic alienation. Hence, policymakers embrace the idea of eavesdropping on many thousands of Muslims in the United States and Europe. This has done little to find terrorists, but a lot to scare many loyal citizens.
The fundamental problem with the "spectrum of radicalization" approach is that it is looking for many "white swans" that do not exist, while missing the rare black swans that might.
Consider the London suicide attacks in July 2005. Even if we restrict the pool of potential extremists to the 1.6 million Muslims living in Britain then, the spectrum of radicalization approach would expect more "homegrown" suicide attackers by orders of magnitude. After all, tens of thousands of British Muslims had met fundamentalist leaders in mosques, lost their jobs, or faced social difficulties that they might view as related to their ethnic or religious backgrounds. But just four men launched the attack.
Further, after a year-long investigation, MI5 found little evidence that any of the four London bombers were economically or socially alienated in significant ways. Mohammad Khan, the leader, was a mentor at a primary school with an exemplary employment record. Shezhad Tanweer drove his own red Mercedes to work in one of his father's several businesses and was a trophy-winning cricket player. Another was known for going to night clubs and talking about girls and cars. None had a history of outbursts or violence, or other signs of significant opposition to British life.
What they did share was deep anger at Western occupation of kindred Muslim populations. Mr. Kahn and Mr. Tanweer left martyr videos to explain their motives.
"Your ... governments continuously perpetuate atrocities against my people all over the world," Khan said. "Until we feel security, you will be our targets."
Recent so-called homegrown terrorists in the United States also reveal little social alienation, but deep anger at foreign occupation. Faisal Shahzad, who was sentenced to life in prison for planning the failed May 1 Times Square car bomb, cited US military activity in his family's native Pakistan and the presence of US troops in various Muslim countries as reasons for his desire to kill American civilians.
While religion contributes in many cases to increased feelings of loyalty toward a kindred community that may be oceans away from an individual's country of citizenship, the primary cause of these horrible phenomena is foreign occupation.
US approach is counterproductive
The US approach in countering this threat has done more harm than good. By simultaneously occupying two Muslim countries and cracking down on Muslim Americans, the US has angered elements of an entire population and made it more likely that they would feel more loyalty to their kindred communities abroad.
Further, aggressive surveillance missed the one behavior trait that the American and British transnational terrorists had in common: self-initiated efforts to communicate with representatives of Al Qaeda and other known terrorist groups to receive approval for their actions.
Counterterrorism operations should focus on what makes these rare events dangerous – that is, the point at which politically active groups seek detailed information and actual materials for lethal action, commonly from international terrorist organizations or their local representatives.
Law enforcement attempts to track large numbers of young Muslim men would incorrectly profile and target an entire community. Such manpower takes resources away from the most productive counterterrorism measure: the search for specific preparations for violent acts.
Robert A. Pape is professor of political science at the University of Chicago and co-author of "Cutting the Fuse: The Explosion of Global Suicide Terrorism and How to Stop It."