The performance of Britain’s overstretched military in Afghanistan is coming under sustained criticism from the Pentagon and US analysts even as Gordon Brown ponders whether to send in further reinforcements.

Robert Gates, the US Defence Secretary who has been asked to remain in his job under Barack Obama, is understood to have expressed strong reservations about counterinsurgency operations in British-controlled Helmand province.

He has already announced plans for a surge of 20,000 US troops into Afghanistan but Mr Brown, who was given a bleak progress report when he visited Afghanistan at the weekend, is said to be reluctant about committing another 2,000 British troops on top of the 8,400 already there.

A total of 132 British soldiers have died in Afghanistan since 2001 and the Government is worried about public opinion turning against the campaign. British officials are concerned that the US may take over control of Helmand – where Mr Gates plans to deploy an extra 5,000 troops – if Mr Brown fails to support the surge. The Americans have grievances over Britain’s lack of equipment, including helicopters, which has left troops unable to perform the same tasks as US counterparts and led to more cautious tactics. There is also grumbling about the regularity with which US airstrikes are called to rescue British troops.

General James Jones, who has been picked at Mr Obama’s National Security Adviser, co-chaired a bipartisan panel this year which cautioned that Afghanistan was close to becoming a failed state and called for better coordination among Nato forces.

It is understood that there has been “tension and resentment” over the air of superiority adopted by British commanders such as Brigadier Nigel Aylwin-Foster, who suggested that his American counterparts needed to take lessons from Britain’s experience in Northern Ireland and Malaya.

David Kilcullen, an adviser to the US State Department, told a recent seminar that there had been “lots of fairly snide criticism” from the British whose attitude had been: “Look at us, we’re on the street in our soft caps and everyone loves us.”

He added that such claims had been undercut by the performance since then. “It would be fair to say that in 2006 the British Army was defeated in the field in southern Iraq.” At the same event, Daniel Marston, an American consultant who until recently was a senior lecturer at the Royal Military Academy at Sandhurst and has been embedded with troops in Afghanistan, said that Britain was being forced to learn some humility after being “embarrassed by their performance”.

Mr Brown hinted at some of his doubts when he told reporters in Kabul: “We are the second largest force in Afghanistan and we will expect as part of the burden-sharing that other countries will do more.” Senior diplomatic sources say there is also frustration in Britain’s military over the lack of a coherent mission statement for the Nato forces in Afghanistan. This has led to problems with US forces sometimes wrecking carefully nurtured community relations in their pursuit of al-Qaeda.

Carter Malkesian, an expert at the Centre of Naval Analysis, said: “Among those in the Department of Defence who are paying attention to these operations, Britain’s reputation has probably fallen. But they still recognise that the British Army, among all the allies, are those that fight the most and fight the best.”

A British officer in Afghanistan expressed surprise at the criticism from the US. “They have few enough allies who will actually do any fighting,” he told The Times.

“It may be that our lay-down is presented as one brigade – when in fact it is far larger – and those away from the coal face simply do not realise the scale of what we do.”

A senior British defence source said: “We are punching above our weight in Afghanistan and are the second biggest contributor of all the Nato allies, so for anyone to single us out for criticism is plainly wrong and unfair.”

Yesterday it emerged that the Ministry of Defence expects its budget for Afghanistan to rise by more than 50 per cent next year from £1.51 billion in the financial year to £2.32 billion.

— A soldier with 29 Commando Royal Artillery became the 133rd British serviceman to die in Afghanistan since the start of operations in October 2001, the Ministry of Defence said. The soldier was at a Forward Operating Base in the Gereshk area of Helmand province when he was wounded by enemy fire. He was taken by helicopter to the military hospital at Kandahar but died later of his wounds. His family has been informed. The death comes three days after four Royal Marines died in two separate explosions in the Sangin area of Helmand. Three were killed by a 13-year-old suspected suicide bomber.

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