Kim Sengupta: The West cannot afford to make any more mistakes

Speaking about the military doctrine the Americans are taking into Helmand, US Army Brigadier General Larry Nicholson said: "Where we go, we will stay, and where we stay, we will hold, and we will build." The policy differs from that adopted by the British forces in the province who could not often hold the terrain, not because they did not want to, but because there were not enough boots on the ground to do so.

The problem this posed could be seen at a number of flashpoints. At Kajaki, I accompanied British troops who fought hard to capture an enemy position and then had to withdraw because it was simply not possible to keep it occupied. Within a day or so, we would again start taking rocket and mortar fire from the same position.

Garmsir, on the other hand, is an example of what can be achieved with adequate troop numbers. I was there in 2006. The main urban centre – known as "the snake's head" because of its topography – had seen constant fighting, changing hands between coalition forces and militants. One attempt to wrest control was undertaken by just 17 British troops alongside 10 Estonians and 200 Afghans.

But last year, a force of 2,000 US Marines, backed by massive firepower, captured Garmsir. And returning a month ago it was still out of Taliban hands, and in fact had a thriving market.

Aware that the 17,000 American troops pouring into Helmand brought with them the possibility of the province turning into a US show, British military commanders asked for 2,500 extra troops to boost the 8,000-strong contingent. The-then defence secretary, John Hutton, supported the proposal but the Prime Minister refused it, authorising instead a temporary deployment of just 700 for the election period in August. The plan now is that with the US forces carrying out the majority of the offensive operations, the British will be able to concentrate on smaller areas where they can provide the necessary security for reconstruction. Whether all this works remains to be seen.

A long hot summer of attritional fighting is expected and the political landscape may change with the 20 August ballot. What the West cannot afford to do is make more mistakes in Afghanistan. And time is not on their side.