Nato battle insurgency and fight for Afghan support
In the queue at the bus station, an intense debate was raging over the merits of suicide attacks against Nato soldiers.
"A small girl was begging the Americans for her life, but they just shot her in the chest and killed her," said a man wrapped in a blanket against the morning cold.
He wagged a finger to emphasise his point. "If foreign forces kill your entire family, the only choice is to blow yourself up," he says.
A tall man in a black turban disagreed. "I don't support the attacks against Nato because if they kill one Nato soldier they also kill 10 Afghan civilians. They are murdering poor, innocent Afghans, not Nato."
A third man said in a quiet voice that he had lost three children, his mother, sister and the rest of his family in an American air strike.
"I was the only survivor out of 12 people. I blame the Taliban because they didn't surrender and the Americans had to bomb them."
The debate had been touched off by my questions about the opinion poll carried out for the BBC, ABC News in the United States, Germany's ARD and the Washington Post.
The survey found that the number of people supporting attacks on foreign forces has tripled over the past year. It was 8% in 2009 and is now 27%, the highest level since 2005.
This is not surprising. It has been a year of intense - and controversial - military activity by Nato. Still, a majority of Afghans oppose attacks on the international troops, and 70% support their work in Afghanistan.
How solid is that support? Just north of Kabul, in an area loyal to the government, we spoke to a village elder, an ethnic Tajik and supporter of the Northern Alliance, traditional enemies of the Taliban.
He greeted me with a hug to demonstrate traditional Afghan hospitality. Yes, he opposed attacks on Nato, he said, but Nato, who had come as "guests and friends" had made a lot of mistakes.
"Our prophet says: 'Neither oppress nor accept oppression'. If Nato is killing people, then we respond according to the guidance of our prophet."
He went on: "God forbid that anyone should want to occupy us. They will take those hopes to their graves. If Nato wishes to leave with dignity and not in failure like the Russians, they should establish good relations with all Afghans even with the Taliban.
"Afghanistan is a conservative country and people believe in their cultural and religious values."
Afghans are tired of war. "We want peace and security in our country," said another of the men who had joined the debate at the bus station.
"Whether the Taliban or the government, they are all our brothers. The Taliban used to be in charge in this country and things were better. There was no fighting."
This last part is not the majority opinion, the Taliban are not popular. Only 9% of those surveyed say the Taliban should be the government. But 73% of those we questioned support negotiations with the insurgents and 37% say they would back a peace deal even if that means ceding some provinces to the Taliban.
It is President Hamid Karzai's strategy to negotiate an end to the war. If the findings of our poll are correct, he remains astonishingly popular.
His approval rating is at a stratospheric 89%, and 86% say the current government should continue to rule the country. This is despite the fact that 96% of people thought corruption was a problem - and many had direct, personal experience of it.
Corruption is one of the things driving new recruits into the arms of the Taliban. "I swear by the Koran that even we can't earn a hundred Afghanis," said a man on crutches in the market.
Describing himself as a former fighter, he went on: "We get billions of dollars of foreign aid. It goes into the pocket of the person with the big belly and thick neck who is a minister."
This was a national poll but - of course - opinion varies according to location and ethnic group. Not surprisingly, people feel most insecure, and most pessimistic about the future, in the south.
Opinion is also malleable. Afghans want to know who will be in charge in their village or valley in five years' time. Some just want to back the winner, whether it's the Taliban or Nato.
The ethnic and regional split in opinion is most important when it comes to southern Afghanistan, where most of the fighting is taking place.
The 27% who agree with attacks on Nato is the figure nationally. In Kandahar, it was 32%, in Helmand, 55%. These are the figures which will determine the success or failure of the Nato and US effort in Afghanistan.
Nato commanders will hope that the ill feeling among such a large section of the population in the south will subside as the tempo of military operations slows.
Nato's own military doctrine acknowledges that a counter-insurgency campaign cannot succeed without support from a majority of the people among whom the battle is fought.