When the final assault came the British and Afghan troops marched into the centre of Musa Qala with barely a shot fired. The Taleban, who for months had made defiant threats to repel the coalition in a bloody battle, had disappeared.

The house-to-house fight that had been feared turned out to be a cautious advance from compound to compound looking for booby traps that the enemy had not planted.

If foreign fighters had planned to embrace martyrdom, they thought better of it at the last minute. Perhaps they had decided that the dusty, filthy backwater in North Helmand that had become of such symbolic importance to Nato and the Taleban was not a good place to die after all.

By dusk yesterday there was no doubt that Musa Qala had been recaptured. The Taleban had vanished into the desert and fields around the town, heading for the dry mountains to the north. British and Afghan troops had scoured the town compound by compound, looking for an enemy which had vanished. They found equipment for roadside bombs and, of all the unlikely things to be lying in the dirt of a formerly Taleban controlled town, pornographic playing cards.

But through a door in a nondescript mud-walled compound was the prize find: £150 million worth of opium piled in 85 sacks against the wall. In front of the opium sacks was a mound of white powder, suggesting the place had been a heroin factory. “It’s a once in a lifetime sight, that,” said an NCO from the Green Howards.

The troops left trip flares at the compound doors in case somebody came back during the night and promised to burn it the next day. It was a stark reminder that Musa Qala has been a centre for Afghanistan’s narcotics trade.

The trade thrives in government-held towns too, underground, but every “narco-khan” and dealer in the province had come to Musa Qala to openly trade in the drugs bazaar that the Taleban had encouraged in order to tax for their war against the British.

Lt Dan Hopwood, from the Royal Engineers, thought the opium find could prove to be the biggest ever in Helmand Province.

To remind the British soldiers that they were still there, every now and again the Taleban lobbed in a mortar.

For the soldiers of the Second Battalion The Yorkshire Regiment who had feared a bloody battle for Musa Qala, a Taleban bastion for ten months, the way the town fell was a relief. None of them was under any illusion that their enemy was beaten. But they were euphoric that they could beat the Taleban so easily in the town their propagandists had made so much of controlling.

A big market town in Northern Helmand built mainly from mud bricks, there was not much to see of Musa Qala when the British and the Afghan troops they are mentoring finally reached the centre on Monday after three days of hard fighting to penetrate Taleban defences on the town’s outskirts.

The bazaar was shuttered. There were a few concrete buildings and a couple of the big houses that Afghans nickname “Narco-villas” on the edge of the desert. Just to the north barren mountains rise behind a trickle of a river.

As dusk fell the Afghan flag was flying from the town’s only monument, the highest point in Musa Qala. Civilians who had fled into the desert when the battle began were beginning to trickle back. Others were believed to be still indoors where they had been in hiding to protect their possessions.

One squaddie said that he had seen a couple of fruit stalls open. “They don’t let fighting get in the way of things for too long here."

British armoured cars drove through the streets past bored looking groups of Afghan soldiers, some festooned with bandoliers of ammunition and their faces swathed with balaclavas and scarves.

One Afghan pedalled a “liberated” bicycle past an armoured car, laughing at an explosion in the near distance. "Taleban,” he said, scornfully.

The centre of the town showed no signs of recent damage. Major Matt Adams said: “Not a bomb or shell landed in Musa Qala . . . The Taleban have withdrawn to fight another day. We are happy. We deceived the enemy into doing what we wanted.”

As night fell and the British troops settled down in a freezing concrete building, they joked and relaxed as the adrenalin of the operation wore off.

The British all praised their Afghan comrades. The operation was the first big one in which Afghans and British have worked together, and the squaddies thought it had gone well. “They can be lazy buggers but they hate the Taleban and they do fight well when they are switched on,” said one.

Corporal Matt Loose said having the ANA around made it much easier to deal with Afghan civilians. "The locals receive us far better when we are with the ANA,” he said.

In the next few days the British will consolidate defensive positions and start to reassure the townspeople who left that they can now get back to normal. Rebuilding and development projects will get under way soon, they hope. And a Shurra — a tribal council — will be convened shortly as part of setting up local administration.

None of the British soldiers expect an easy time in Musa Qala, however. “It was too bloody easy,” said one blunt Yorkshireman. “The Taleban will be back to have another go.”

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