As America prepares to mark the ninth anniversary of 9/11, homegrown terrorists like David Headley and Faizal Shahzad have emerged as the biggest security threat to the country, a group of top national security experts have warned.
A new report by the Bipartisan Policy Centre's National Security Preparedness Group says the US does not have a real strategy to counter the homegrown threat.
"A key shift in the past couple of years is the increasingly prominent role in planning and operations that US citizens and residents have played in the leadership of Al Qaeda and aligned groups, and the higher numbers of Americans attaching themselves to these groups," the report says.
Among other things, the 42-page analysis warns of the expanding role played by US citizens and residents within Al Qaeda and allied organisations. It describes an increasingly wide range of "US-based jihadist militants" who do not fit "any particular ethnic, economic, educational, or social profile."
The report also points to an "Americanisation" of the leadership of al-Qaida and its allied groups, noting that radical cleric Anwar al-Awlaki, who had links with suspects in the failed Times Square bombing, including Pakistani-American Faisal Shahzad and the Fort Hood shootings, grew up in New Mexico.
It also notes that Chicago resident David Headley, a LeT operative, had played a major role in the 2008 Mumbai attacks.
The United States, the report asserts, now confronts "a dynamic threat that has diversified to a broad array of different attacks, from shootings to car bombs to simultaneous suicide attacks to attempted in-flight bombings of passenger aircraft."
Would-be terrorists are now likely to attempt more frequent and less sophisticated attacks compared to what transpired in 2001, the report states. Preventing such attacks will require greater involvement from state and local public safety officials, CNN reported.
The report was produced by the non-partisan National Security Preparedness Group, chaired by Lee Hamilton, a former lawmaker from Indiana, and former Governor Tom Kean, who also headed the 9/11 Commission.
"Al Qaeda or its allies continue to have the capacity to kill dozens, or even hundreds of Americans, in a single attack," the report concludes. And Al Qaeda leaders still "hope to inflict mass casualty attacks in the United States."
While the threat now is less severe "than the catastrophic proportions of a 9/11-like attack, (it) is more complex and more diverse than at any time over the past nine years."
Al-Qaeda and its allies have been hampered, the analysis says, by US drone attacks in Pakistan and negative attitudes toward Islamic extremists in both Pakistan and the broader Muslim world.