The American Security Project examined 32 attacks that were thwarted since 9/11 and found that in a majority of cases, “traditional law enforcement techniques and methods developed prior to 9/11, direct and indirect action by concerned citizens, and international law enforcement cooperation contributed significantly to identifying terrorists and preventing attacks.”

 

Specifically, in 13 cases, undercover agents, informants and physical surveillance played an important role. In five cases, concerned citizens alerted authorities about suspicious behavior. In another five cases, including that of Khalid Sheikh Mohammed, the alleged mastermind of the 9/11 attacks, “international counterterrorism partners” played an active role.

 

In three cases, however, including that of the Lackawanna Six, law enforcement authorities did use provisions of the Patriot Act and FISA amendments, such as roving wiretaps and “delayed notification searches.”

 

Two cases remain in dispute. The Bush administration claimed that they learned about al-Qaeda’s plot to crash planes into Los Angeles’ Library Tower from the torture of Khalid Sheikh Mohammed. However, other evidence suggests that the plot was discovered before Mohammed was even captured.

 

In May 2002, former Chicago gang member José Padilla was arrested as a material witness. The Bush administration claimed that they learned about Padilla by torturing Abu Zubaydah. Others, including FBI agent Ali Soufan, who interrogated Zubaydah before he was tortured, have stated that Zubaydah revealed information about Padilla before the torturers got hold of him. Padilla was later convicted of conspiracy to commit murder and kidnapping overseas and was sentenced to more than 17 years in prison.

- David Wallechinsky, Noel Brinkerhoff,

 

 (by Germain Difo, American Security Project) (pdf)

How Serious is the Threat of Terrorism in the United States? (by David Wallechinsky and Noel Brinkerhoff, AllGov)