A Taliban commander says there can be no deals until the US leaves Afghanistan
The US military has an effective weapon in the intelligence war with the Taliban - the chocolate nut muffin.
"It's a head game," said Colonel "T", who is in charge of interrogations at Parwan Detention Centre, the US military's gleaming new prison for the Taliban.
Often, what it took to get a hardened insurgent talking was the offer of a chocolate nut muffin, he said. That, or apple cinnamon.
Military interrogations have been governed by an updated US Army Field Manual since 2006.
It prohibits waterboarding, sleep deprivation and putting prisoners in stress positions. President Barack Obama made that the rule for everyone, including the CIA, in 2009.
But the bad image from previous abuses persists, and US military prisons remain places of fear for many Afghans.
That is damaging to US war aims in Afghanistan, where, the generals believe, victory will depend on winning over the Afghan people.
So Parwan was built to replace the notorious Bagram.
Public Relations
It is - in marketing terms - an exercise in "rebranding". We got an escorted tour where officers proudly showed off the new cells, dental clinic and kitchens.
"Prisoners put on 25lb (11.3kg) by the time they leave here," one said.
Previously, it would have been unthinkable for journalists to visit Parwan's two large interrogation hangars, filled with the small cabins where prisoners are questioned.
"One table, three chairs," said Colonel "T" repeatedly when I asked him about the techniques used by his soldiers and the tools available to the interrogator; nothing more.
The men at Parwan have not had a criminal trial. They have been interned on the basis of suspected Taliban membership but American officials say they are not denied due process.
Showing off the "Detainee Review Boards" is another reason to bring journalists to Parwan, demonstrating the "transparency" of the legal process to the Afghan people.
The hearings are held in a windowless conference room. When we arrived, a detainee was pleading for freedom after two years in one of Parwan's large cells, shared with 20 other men.
He sat in the centre of the room, dressed in one of the red uniforms for maximum-security prisoners, handcuffed and shackled.
He had been arrested in southern Afghanistan while planting an IED or roadside bomb - a photograph of the device was projected on a big screen on the far wall.
He said first that he had been forced to do it by a man to whom he owed money.
Then he said he didn't know that the two wires he was asked to connect were part of a bomb, and he insisted he was not an insurgent.
We left before the hearing concluded, but he didn't look as if he was convincing the panel.
Part-Time Fighters
Everyone else in the room - including the man appointed to help and advise the detainee - was from the US military.
The US says some Taliban militants are fighters simply because they can't find other jobs How could this deliver a just outcome, I asked Mike Gottlieb, the civilian deputy director of the task force that runs the prison. The hearings were "fair, thorough and robust," he said.
"The process is designed to sort out the worst of the worst offenders from those who are accidental guerrillas or part-time participants in the insurgency."
The idea, he went on, was to identify the "$5-a-day Taliban who are suitable for re-integration".
We met some of those in the prison grounds. Men who - the US military said - had once planted bombs were now being taught how to plant sunflowers or bake bread.
The Americans hope that giving former insurgents skills will stop them taking up arms again. Some are thought to fight just because they can't find a job.
But many of the Taliban are deeply ideological. After we left Parwan, we went to meet a middle-ranking Taliban commander.
We saw him in Kabul. The capital is under government control but the insurgents can still come and go.
Taliban commanders say their fight will continue unless the US leaves Afghanistan. Both sides approached the meeting somewhat nervously.
Muwlawi Abdel Rahman was wearing dark glasses and wrapped in a large peach-coloured pashmina by way of disguise.
We sat on a carpeted floor as he told me he had 900 fighters in Wardak province.
As Mullah Omar did in his Eid message, he repeated the Taliban's very simple line: no peace negotiations until the Americans leave.
"My advice to the Americans is, if they love their lives, if their families are suffering from their presence here or their deaths in Afghanistan, they should go. As long as one American remains in Afghanistan, we won't stop our jihad."
What then, I asked?
"The day the foreign forces leave Afghanistan, we will sit down with the government... if they do not accept our demands, we will continue our attacks. There will be jihad until we have an Islamic government in this country based on Sharia law."
But weren't many Afghan civilians being killed in the jihad, I asked?
"We're doing our best to avoid civilian casualties," he said. "When we plant mines for American convoys, most of the time we don't do it in civilian areas. We've even stopped using so many suicide bombers to reduce civilian casualties."
Dual Identity
Despite those assurances, there are continuing civilian casualties from the Taliban campaign. Even so, the insurgents are getting new recruits.
A member of our local staff met and filmed someone who had just joined up. He was working in a government ministry - a civil servant by day, a Taliban volunteer by night.
"I joined the Taliban because of what the Americans are doing to this country," he told us.
"They break down doors in the middle of the night; they kill innocent people. The infidels have occupied our country. If I die fighting them then at least I will get the chance to be martyred."
None of that comes as any surprise to Major General Philip Jones, the British officer who is in charge of Nato's efforts to get fighters to leave the insurgency.
"There's more violence now than there was a year ago," he said. "One of things that has proved remarkably resilient about the insurgency is their ability to recruit people. There always has to be some sort of political dialogue that takes you to an end of this conflict - not a military solution."
Nato hopes it can persuade insurgents to leave the Taliban faster than it recruits. That could be the difference between success or failure for the campaign in Afghanistan.