Osama bin Laden was unquestionably within reach of U.S. troops in the mountains of Tora Bora when American military leaders made the crucial and costly decision not to pursue the terrorist leader with massive force, a Senate report says.

The report asserts that the failure to kill or capture bin Laden at his most vulnerable in December 2001 has had lasting consequences beyond the fate of one man. Bin Laden's escape laid the foundation for today's reinvigorated Afghan insurgency and inflamed the internal strife now endangering Pakistan, it says.