EXCLUSIVE: Terror Attacks Against U.S. At All-Time High

May 26, 2010 — -- The pace and number of attempted terror attacks against the U.S. over the past nine months has surpassed the number of attempts during any previous one-year period, according to an internal Department of Homeland Security report issued on Friday, May 21.

The report notes chillingly that while US officials "lack insights" they believe that "operatives are in the country and could advance plotting with little or no warning."

The DHS "Intelligence Note," a short, non-classified report, makes concrete the concerns of a number of homeland security experts who have discussed with ABC News the pace and nature of the individual attempts. The report notes that al Qaeda in the Arabian Peninsula and the Pakistani Taliban have "expanded their focus" to include the United States.

Homeland Security and law enforcement officials interviewed by ABC News on the condition their names not be used are concerned that the pace will continue to ramp up and that increasingly the attackers will be difficult-to-detect homegrown extremists.

"Recent attempted attacks and plots in the United States progressed to an advanced stage largely because of these groups' ability to use operatives that have access and familiarity with the U.S. and their employment of new and varied attack plans," the three-page note concludes.

"Public statements highlighting group leaders' intent to strike … and probable terrorist perception of success in challenging the U.S. even through failed attacks, suggest al Qaeda and associated groups will try to conduct operations in the United States with increased frequency."

The attacks included the alleged May 1 attempt by Faisal Shahzad to detonate a car bomb in Times Square and the attempted Christmas Eve bombing of a Northwest Airlines Flight 253 by a suspect who managed to carry high powered explosives aboard the aircraft concealed in his underwear. In each attempt, U.S. intelligence failed to detect and prevent the attacks and it was only through failures in the construction of the improvised explosive devices that the attacks did not cause mass causalities.