By John Simpson
The Taliban in Afghanistan have told the BBC that there is no question of their entering into any kind of negotiations with Nato forces.
It comes after US commanders and the British army chief of staff, Gen David Richards, suggested that it might be useful to talk to the Taliban.
The Taliban statement is uncompromising, almost contemptuous.
They believe they are winning the war, and cannot see why they should help Nato by talking to them.
They assume, perhaps wrongly, that the Americans are in disarray after the sacking of the Nato commander Gen Stanley McChrystal last week, and regard any suggestion that they should enter negotiations with them as a sign of Nato's own weakness.
June, they point out, has seen the highest number of Nato deaths in Afghanistan: 102, an average of more than three a day.
Nowadays it is extremely hard for Westerners to meet Taliban leaders face to face, either in Afghanistan or in Pakistan.
But a trusted intermediary conveyed a series of questions to Zabiullah Mujahid, the acknowledged spokesman for the Afghan Taliban leadership, and gave us his answers.
The text runs as follows:
"We do not want to talk to anyone - not to [President Hamid] Karzai, nor to any foreigners - till the foreign forces withdraw from Afghanistan.
"We are certain that we are winning. Why should we talk if we have the upper hand, and the foreign troops are considering withdrawal, and there are differences in the ranks of our enemies?"
This is propaganda, of course - yet many Afghans, even those who hate and fear the Taliban, are coming round to exactly the same view.
The Taliban are still deeply unpopular in many parts of the country.
Memories are still vivid of the brutal and extreme way they governed from 1996 to 2001.
They, together with their supporters, certainly do not represent anything near a majority of the Afghan people.
They are still predominantly a Pashtun faction, and when they were in power they caused much anger by imposing Pashtun cultural norms on the complex and varied peoples of Afghanistan.
Nevertheless, there is an instinctive and widespread dislike of having foreign troops, and especially non-Muslim ones, based in Afghanistan.
People who do not support the Taliban know that the Nato-led force is preventing the Taliban from returning to power.
But the dislike of occupying forces goes very deep.
The key to the Taliban's remarkable success in capturing Kabul from the more moderate mujahideen leadership in 1996 was their ability to convince dozens of uncommitted warlords that they were bound to win.
Many of these warlords were not themselves Pashtun, and often were not extreme Muslims.
They joined the Taliban simply to be on the winning side.
The Taliban have not forgotten this. If they can convince people that they are beating the British and Americans, more and more local warlords will join their cause.
The difficult job facing Gen Petraeus, who takes over control of the Nato forces in Afghanistan, will be to change this perception.
When he was in charge of coalition forces in Iraq he managed to change the widespread perception that the war there was unwinnable.
He presented the draw-down of US forces as a victory: they had, he said, done the job they had come to do, and succeeded. Therefore they could leave Iraq as victors.
Cynics may point out that the number of deaths from terrorism in Iraq is still appallingly high, and that the fragile Iraqi government is struggling to do anything about it.
But since most American news organisations have pulled out of Baghdad, little news of what is happening in Iraq seeps through to the United States.
Gen Petraeus will no doubt try to replicate his remarkable Iraqi success in Afghanistan.
Yet it will be harder, and doubts about the value of the operation are already growing in every Nato country.
His main aim will be to reverse the growing belief in Afghanistan that the Americans, the British and the others will pull out soon, and leave the country to fight out its own war - with the Taliban the likely winners.
It is likely to be the hardest fight of his career.