“Al-Qaeda and its allies are likely to attempt small-scale, less sophisticated terrorist attacks in the United States, senior Obama administration officials said Wednesday, noting that it’s extremely difficult to detect such threats in advance.
‘Unlike large-scale, coordinated, catastrophic attacks, executing smaller-scale attacks requires less planning and fewer pre-operational steps,’ said Homeland Security Secretary Janet Napolitano, testifying before the Senate Homeland Security and Governmental Affairs Committee. ‘Accordingly, there are fewer opportunities to detect such an attack before it occurs.’
Terrorism experts have puzzled over al-Qaeda’s apparent unwillingness after the Sept. 11, 2001, attacks to use car bombs, improvised explosives and small arms to conduct assaults in the United States. The group appeared fixated on orchestrating another dramatic mass-casualty event, such as the simultaneous downing of several commercial airliners. “
(Source: Risk of small-scale attacks by al-Qaeda and its allies is rising, officials say)