The string of recent arrests involving American citizens in terror plots against the U.S. have highlighted what appears to be a trend in transnational Islamist terrorism: growing domestic radicalization. This phenomenon has appeared in the U.K., France, Germany and Australia, among others countries. Security officials in all these countries now routinely emphasize that the greatest threat they face is "homegrown terrorism."
While these individuals lack the training, resources and expertise to carry out attacks against high-profile, well-protected facilities, they represent a serious challenge for several reasons.
First, they usually have no prior attachment to extremism and, hence, typically exist below the "radar" screen of law enforcement and intelligence agencies. This makes them extremely difficult to track and pre-empt. Second, they are unpredictable because their actions are neither defined nor bounded by the organizational constraints that are normally imposed on members of more structured terrorist groups.
Third, while they lack the ability to hit so-called "hard" targets decisively, they are perfectly able to attack the plethora of "soft" venues that abound, like shopping malls, cinemas, mass surface transportation, restaurants and office complexes.
Fourth, in the cases of religious "converts" the desire to contemplate extreme violence is likely to be especially strong as this may well be viewed as the most visible way of demonstrating and validating their Islamist credentials. Finally, they can greatly inflate the perceived threat of militant extremism because their actions are specifically directed against places central to day-to-day lives of ordinary citizens.
One of the main factors serving to encourage the growth of homegrown terrorism is the Internet. The number of active extremist Web sites around the world has exploded over the last several years and by 2006 was thought to number around 5,000.
These forums not only provide a readily accessible virtual platform through which to disseminate extremist propaganda, in so doing they also act as a highly powerful means for self-radicalization. And as cases in the U.S. show, the audiences for these sites are not necessarily Muslims.
What does all this mean for future threat containment? A trend toward homegrown terrorism should presumably reduce strategic attacks against iconic targets and venues. But locally radicalized individuals will provide al-Qaeda and associated movements with an amorphous cadre of militants that can be used to show that the transnational terror threat is one that exists in all places at all times.
Peter Chalk is a senior policy analyst with the RAND Corporation and associate editor of "Studies in Conflict and Terrorism."
This op-ed was part of a NYTimes.com Room for Debatate post on "Behind the New U.S. Terror Cases."
This commentary originally appeared on NYTimes.com on March 18, 2010. Commentary gives RAND researchers a platform to convey insights based on their professional expertise and often on their peer-reviewed research and analysis.