Audio gallery from Helmand, pictures by Richard Mills and commentary from Anthony Loyd

The soldiers' knock on the gate came just after 8am on a bitter morning of freezing rain. The Afghans were already awake and tending their livestock inside the compound. There were nearly 50, the extended family of five brothers. Farmers, they had lived in their area for generations. Their ancestors lay buried in a cemetery on a knoll above their home.

“I told them there was bad news,” Warrant Officer Les Bering, the Danish soldier, said. “That they had to go.”

Unknown to the Afghans, their home was the focal point of Operation Thunder, an ambitious British and Danish plan to seize, hold and build on a chunk of territory in the Taleban heartland of the Upper Gereshk Valley, central Helmand. Their spacious compound just happened to be the intended base for FOB Armadillo, a new base of Nato troops. So they had to move. That very day.

There was compensation. After two hours of negotiation, with British troops keeping watch, the Danes agreed to pay the brothers a four-figure sum in dollars, followed by a relatively handsome monthly rent. Even so, the experience left a bitter aftertaste for many of the soldiers.

“It was not a high point to see an eight-year-old girl walk out of her home into January rain, clutching a watering can in one hand and a chicken in the other, knowing that you have been somehow responsible for that,” Captain Jamie Russell, commander with the Coldstream Guards, said. “A lot of the blokes felt bad about it.”

The Afghans departed with good grace. No sooner was the last out of the gate than British engineers and more Danish troops were inside it. As Warrior and Leopard tanks silhouetted the ridgeline above, bulldozers arrived to begin transforming the farm into a defensive and expansive strongpoint, complete with battlements, sangars, accommodation, artillery positions, an aid post and helicopter landing site.

The operation is the latest and most significant in a new strategy by a British-led brigade in Helmand that is tired of launching yet another offensive in the valley from which they later withdraw only to have the Taleban reoccupy cleared ground.

The area, known as the Green Zone because of the vegetation on each bank of the Helmand River, is regarded as the main Taleban sanctuary in the province and runs north from Gereshk up to Sangin and eventually Kajaki. Nato commanders want to build bases on both banks right through the region so that they can deny it to the Taleban and conduct reconstruction operations for the population. FOB Armadillo is the latest and farthest up the valley and leaves the gap to Sangin only nine miles (15km) wide.

Colonel Kim Kristensen, the Danish commander of the battle group, said: “We are getting very close to closing the final gap. It's a golden opportunity that we shall not miss.”

The Taleban appeared to have disappeared as the new Nato camp was constructed in their midst. Some of their absence could be explained by the extreme cold and vile conditions of the Afghan winter.

“It's the same for them as it is for us in these conditions, only worse,” said Sergeant Nunn, leading a patrol of Scots Guards into the valley below the nascent base. “Their vehicles, kit and ammunition get bogged down too.”

Attrition was another factor in the Taleban's reluctance to fight. They have suffered fearful losses in the valley over the summer and autumn, and as Royal Engineers shored up FOB Armadillo's defences, radio chatter revealed that some demoralised insurgents were abandoning their nearby positions, while a significant internal dispute brewed among Taleban commanders over how best to motivate their reluctant men to fight.

The Danes have brought 52-tonne Leopard II tanks to the area. Their sighting system is accurate enough to put a shell through the door of a Taleban-held compound with 95 per cent accuracy at a range of 2.5 miles (four kilometres), negating much of the reliance on close air support. Three weeks ago the tanks savaged a strong Taleban ambush, killing two senior commanders and many fighters.

“The Leopards have had exactly the psychological effect that I hoped they would, both on the Taleban and my men,” Colonel Kristensen added. “The Taleban know that when they start a contact they have between five and ten seconds before it's over. And far from frightening the locals, the elders in the shuras tell us that tanks are the best tools against the Taleban.”

Doubtless the arrival of spring will bring Taleban reinforcements, but they will find the valley a very different place from the one they left behind. In the areas controlled by Nato, officers spoke of a bounty of intelligence from locals returning to their homes and of a growing groundswell of anti-Taleban sentiment.

Some of this was apparent when a patrol below FOB Armadillo encountered a teacher.

The man's school was closed by the Taleban, and he had tears in his eyes when he greeted the Nato troops, before warning them of a Taleban position two compounds farther on across the fields.

For the five brothers whose farm once lay beneath FOB Armadillo, Nato's new push up the Helmand Valley was one of mixed reward.

“The Danes treated us in a kind and humanitarian way when they asked us to leave our home,” Pir Mohammed, one of the brothers, said.

“And it is better than the Russian time - they would kill all the animals and people. But no one likes to be told to leave their home.

“We are farmers. Even though they gave us money we can no longer till our fields or work here.”

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