The threat posed by fundamentalist Islamic terrorists has changed a great deal over the last decade. Before the attacks of September 11, 2001, al-Qaeda had a well funded and centralized leadership that enabled them to plan large-scale and spectacular attacks. Since then, military operations in Afghanistan and Pakistan (including drone strikes) and the arrest of several key terrorist operatives have increasingly marginalized the core al-Qaeda group based in and around the Federally Administered Tribal Areas of Pakistan. This, coupled with stringent counter-terrorism measures in the developed world, has hindered the ability of al-Qaeda’s core to execute attacks on the scale of September 11, 2001. Intelligence suggests one of the last plots that involved core al-Qaeda was the aircraft bomb plot in 2006 that aimed to bring down several transatlantic flights by detonating liquid explosives.
Consequently, the threat has since shifted to softer targets, with attacks and plots becoming more localized in nature. Over recent years, al-Qaeda has expanded its reach by offering guidance and training to like-minded groups and individuals, facilitating attacks in several regions and countries, including Afghanistan, Iraq, North Africa, Pakistan, Saudi Arabia, Spain, the United Kingdom and Yemen. There has also been a drive to encourage lone individuals to carry out attacks. Before September 11, 2001, intelligence agencies were only aware of one al-Qaeda cell in Europe. Today, they believe hundreds of radical Muslims from several European countries have traveled to Pakistan’s tribal areas for training and returned to their country of origin. Such lone attackers have also been discovered in the United States.
Recent unsuccessful attacks - including the attempted bombing of an Army recruitment center in Baltimore, Maryland, the plot to bomb a Christmas tree lighting ceremony in Portland, Oregon, the car bombing attempt in Times Square, New York, and the failed suicide attack in Stockholm, Sweden - were almost exclusively executed by homegrown operatives, not militants dispatched by core al-Qaeda. To date, the majority of these home grown cells have lacked the necessary planning and bombmaking expertise to mount a successful attack. However, intelligence agencies continue to warn it is almost inevitable that a cell will successfully execute an attack at some point in the future. While intelligence officials expect conventional explosives to be used in such plots, they caution that terrorists continue to pursue nuclear, biological, chemical or radiological (NBCR) devices.