A report to the US Senate says Osama bin Laden was within the grasp of American military forces in Afghanistan in late 2001 but US leaders decided not to deploy the means to pursue him. The report prepared by Democratic party's staff in the Foreign Relations Committee says bin Laden and his top followers were cornered in the Tora Bora mountains in Afghanistan but the Bush administration did not send the reinforcements necessary to catch him. The report says failure to kill or capture bin Laden when he was at his most vulnerable has had lasting consequences beyond the fate of one man, laying the foundation for the protracted insurgency in Afghanistan. The report comes just days before President Obama is due to announce his decision on boosting American troop numbers in Afghanistan. It says the previous Defence Secretary Donald Rumsfeld and his top military commanders must take some of the blame for the current state of conflict.