"You can never win the war in Afghanistan," said 'Colonel Imam', who ran a training programme for the Afghan resistance to the Soviet Union's occupation from 1979 to 1989, and then helped to form the Taliban.
"I have worked with these people since the 1970s and I tell you they will never be defeated. Anyone who has come here has got stuck. The more you kill, the more they will expand," Imam told The Sunday Times.
Imam has offered to find the Americans a way out and says the US must negotiate with its enemies.
"We can give them a face-saving solution but they must change their strategy."
First, he said, they must spend billions on reconstruction. Then they must open talks with Omar rather than the so-called moderates.
"When are you people going to understand that there is no number two Taliban," he said.
"Those who break away from Taliban have no place in the society. You may make deals in Dubai or Saudi Arabia, but when they come back to Afghan and people know they compromised with the Americans, they are finished."