Washington Post:
Intelligence officials think that bin Laden is hiding in the northern reaches of the autonomous tribal region along the Afghanistan-Pakistan border. This calculation is based largely on a lack of activity elsewhere and on other intelligence, including a videotape, obtained exclusively by the CIA and not previously reported, that shows bin Laden walking on a trail toward Pakistan at the end of the battle of Tora Bora in December 2001, when U.S. forces came close but failed to capture him.
Many factors have combined in the five years since the Sept. 11, 2001, attacks to make the pursuit more difficult. They include the lack of CIA access to people close to al-Qaeda’s inner circle; Pakistan’s unwillingness to pursue him; the reemergence of the Taliban and al-Qaeda in Afghanistan; the strength of the Iraqi insurgency, which has depleted U.S. military and intelligence resources; and the U.S. government’s own disorganization.
Here.