A look back at the years leading up to the fall of Kabul and the perilous evacuation of civilians trapped inside the embassy in the hours following the Taliban's takeover of the country.

FRONTLINE reports from the lawless Pakistani tribal areas along the Afghanistan-Pakistan border and reveals how the area has fallen under the control of a resurgent Taliban militia. Despite the presence of 80,000 Pakistani troops, the Taliban and their supporters continue to use the region as a launching pad for attacks on U.S. and coalition forces in Afghanistan. In a region little understood because it is closed to most observers, FRONTLINE investigates a secret front in the war on terror.