CSIS, 8 Mar 10: A Growing Terrorist Threat? Assessing "Homegrown" Extremism in the United States
The five “cases” discussed in this paper—which were part of a larger trend of heightened domestic extremism during 2009—proved so unsettling, in part, because they seemed to contradict much of the recent thinking concerning radicalization and terrorism in the United States. Both policymakers and the public have tended to classify extremist violence as a problem with origins outside the United States. This trend gained momentum after the September 11, 2001, attacks, when President George W. Bush invoked the Afghanistan and Iraq Wars as part and parcel of the United States’ counterterrorism strategy. As the president said in a June 2005 speech, we were focused on “taking the fight to the terrorists abroad, so we don’t have to face them here at home.”

But what if the terrorists we face already live here at home? As this report shows, the acceleration of domestic extremism poses a number of serious considerations for U.S. policymakers and officials in charge of counterterrorism and homeland security. Had they successfully linked up with militants in Afghanistan, for instance, the “Northern Virginia Five” could have used their fluency in English and understanding of American culture to aid Taliban attacks on U.S. troops. David Coleman Headley appears to have utilized his U.S. passport to gain access to India to undertake preparations for the Mumbai attacks; his alleged coconspirators, operating with Pakistani documentation, faced far more significant barriers to entry.

Najibullah Zazi offers the clearest example of an oft-discussed hypothetical—namely, that U.S. legal residents and citizens might travel abroad to receive explosives or weapons training in terrorist camps, then return here to plan and execute attacks. Given the United States’ largely effective post-9/11 efforts to prevent foreign terrorist infiltration, these sorts of homegrown recruits may represent the best chance for al Qaeda and other global terrorist organizations to launch a major attack in the United States. Of course, would-be domestic extremists need not acquire training abroad to inflict substantial harm at home, as the Fort Hood shootings revealed. The threats posed by homegrown extremism, then—even if not widespread—demand a close examination....