Al-Qaeda leader Osama bin Laden was calculating how many Americans had to be killed to force the United States out of the Middle East.
That's according to U.S. officials who are analyzing bin Laden's writings discovered in his hideout in Pakistan and brought by U.S. forces to the United States after they killed him on May 2.
The officials -- speaking on condition of anonymity -- said five computers and about 100 removable digital storage devices or flash drives were discovered in the house in Abbotabad, as well as a diary that bin Laden wrote by hand.
According to the officials, bin Laden told his followers that only a massive attack on the scale of the September 11, 2001, attacks would force the United States to reconsider its policy in the Middle East.
compiled from agency reports