Afghanistan: Former US ambassador Khalizad on 'historic' election
5 April 2014 Last updated at 13:15 BST
Voters in Afghanistan are going to the polls on Saturday to choose a new president amid tight security, in what will be the nation's first ever democratic transfer of power.
American diplomat Zalmay Khalizad was born in Afghanistan and knows the country well.
He served there as America's ambassador after the invasion which followed the 9/11 attacks and became so influential he was dubbed the country's "Viceroy".
Speaking on the BBC's Today programme, John Humphrys suggested to him there was no possibility that the Taliban would accept the outcome of the election.