>> reporter: bin laden's base of operations is afghanistan. here, the fundamentalist taliban regime provides sanctuary. so immediately after september 11th, small u.s. commando teams begin working with local warlords who oppose the taliban to get bin laden. cia officer gary burnson is on the ground helping lead the mission. >> keep pushing people forward. keep taking ground. keep working with northern alliance or other tribal units to seize territory and to kill the enemy. >> reporter: concerned that a large deployment of american troops would provoke a backlash, the americans are, in effect,