Over three years and on as many continents, US officials met in public and secret at least 20 times with Taliban representatives to discuss ways the regime could bring the suspected terrorist Osama bin Laden to justice.
Talks continued until just days before the September 11th attacks, and Taliban representatives repeatedly suggested they would hand over bin Laden if their conditions were met, sources close to the discussions said.
Throughout the years, however, State Department officials refused to soften their demand that bin Laden face trial in the US justice system. It also remained murky whether the Taliban envoys, representing at least one division of the fractious Islamic regime, could actually deliver on their promises.
The exchanges lie at the heart of a long and largely untold history of diplomatic efforts between the State Department and Afghanistan's ruling regime that paralleled covert CIA actions to take bin Laden. In the end, the two tracks proved equally fruitless.
In interviews, US participants and sources close to the Taliban discussed the exchanges in detail and debated whether the State Department should have been more flexible. Earlier this month, President George Bush summarily rejected another Taliban offer to give up bin Laden to a neutral third country. "We know he's guilty. Turn him over," Mr Bush said.
Some Afghan experts argue that the United States never recognised the Taliban's need for a face-saving formula. Officials never found a way to ease the Taliban's fear of embarrassment if it turned over a fellow Muslim to an "infidel" Western power.
"We were not serious about the whole thing, not only this administration but the previous one," said Mr Richard Hrair Dekmejian, an expert in Islamic fundamentalism and author at the University of Southern California.
"We did not engage these people creatively. There were missed opportunities."
US officials struggled to communicate with Muslim clerics unfamiliar with modern diplomacy and distrustful of the Western world, and they failed to take advantage of fractures in the Taliban leadership.
"We never heard what they were trying to say," said Mr Milton Bearden, a former CIA station chief who oversaw US covert operations in Afghanistan in the 1980s.
State Department officials assert that despite hours of talks and proposals that were infuriatingly vague, the Afghan rulers never truly intended to give up bin Laden.
US negotiators started out "very, very patient", one official said. But over the course of many meetings, the envoys "lost all patience with them because they kept saying they would do something and they did exactly nothing".
The meetings took place in Tashkent, Kandahar, Islamabad, Bonn, New York and Washington. There were surprise satellite calls, one of which involved a 40-minute conversation between a mid-level State Department bureaucrat and the Taliban's supreme leader, Mullah Mohammad Omar. There was a surprise Taliban visitor to Washington, bearing a gift carpet for Mr Bush.