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.
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.