The attack on a bus transporting U.S. servicemen from Frankfurt's International Airport is the latest in a series of incidents involving homegrown terrorists.
In this case the alleged perpetrator, Arid Uka, was described as a model youth who showed no sign of anti-social behavior, much less a willingness to commit murder. This kind of "invisibility" renders potential terrorists difficult to identify or pre-empt. But other factors make it more challenging still.
First, these individuals typically have no prior attachment to radicalization and operate under the radar of police or intelligence agencies. Second, in many cases their extremism emerges after frequent viewings and postings on the Internet, a medium hard to monitor. Third, most homegrown terrorists do not belong to any formal radical groups. Rather, they work alone and demonstrate their commitment through self-conceived actions on very short notice. This appears to have been the case with Mr. Uka. According to prosecutors, he decided to attack after seeing a video on YouTube that supposedly showed American soldiers raping a girl in Afghanistan.
How should police and intelligence agencies deal with the specter of homegrown terrorism? One of the best tools available is intelligence gleaned from the local community. A recent study by RAND and the Institute for Homeland Security Solutions found that over half of the plots foiled in the U.S. between 1999 and 2009 were uncovered after a member of the public reported seeing something suspicious. This only underscores the critical "force multiplier" effect that can result from the creation of robust and trusted networks at the local level.
While American authorities are moving to institutionalize community-based information flows, they are entering the game late. More resources should be given to support these nascent endeavors which, if appropriately levered, could help greatly expand the scope of national surveillance.
This op-ed was part of a NYT Room for Debate discussion: "What Is the Terrorism Threat Now?"
Peter Chalk is a senior analyst with the RAND Corporation.
This commentary originally appeared on NYTimes.com on March 10, 2011. Commentary gives RAND researchers a platform to convey insights based on their professional expertise and often on their peer-reviewed research and analysis.