The fighting shows no sign of easing
As the death toll continues to rise past 200, the BBC correspondent in Kabul, Ian Pannell, considers whether the British military and political aims in Afghanistan can be met.
This has been the hardest summer for British troops in Afghanistan since 2001.
They continue to fight an enemy that is better trained, better resourced and more lethal than ever.
Although public support for the troops themselves is perhaps higher than ever, the ongoing conflict and its rising casualty rate is attracting fresh criticism.
UK forces moved into the southern province of Helmand in the spring of 2006. Speaking at the time, the Defence Secretary John Reid said their mission was to help Afghans reconstruct their economy and democracy.
Explaining the deployment, he said that "we would be perfectly happy to leave in three years time without firing one shot because our mission is to protect the reconstruction", whereas it was the job of US forces to "go after and chase and kill and destroy the terrorists".
But almost immediately, British troops ran into significant and sustained armed opposition from the Taliban.
After being overthrown by US-led forces in 2001, the insurgents used a power-vacuum in the south and east to regroup and consolidate.
By the time soldiers from the 16 Air Assault Brigade arrived in Helmand, the insurgents were ready and the two sides have been fighting ever since.
The Taliban launched ferocious full-frontal assaults on the small temporary bases established by the British.
This was when the troops first started to incur significant losses and serious injuries. They were forced to take up essentially defensive positions and the work of protecting reconstruction took a back seat.
Over the last three years, the nature of the fighting has evolved. Increasing numbers of UK troops have been deployed and the Taliban have been forced to adopt increasingly asymmetric tactics, in particular the use of so-called "improvised explosive devices" (IEDs).
Gradually the main towns in Helmand were brought under partial control and development work got underway, albeit in a limited way.
But by 2008, senior military and political figures concluded that a "strategic stalemate" had been reached.
This year has been very different. The US deployed 11,000 US Marines to Helmand as part of a surge in forces, freeing up the British to go on the offensive.
Operation Panther's Claw was an ambitious move to try and clear the Taliban from a large swath of territory in the central Helmand River Valley.
It was part of a plan to clear the area ahead of presidential elections on 20 August and to create a contiguous strip of heavily-populated land under Isaf control.
The homecoming of British coffins has become a regular event
But this has come at a cost. July was the deadliest month for UK troops and so far August has also seen a high casualty level.
Every year, the level of violence has increased and with it the casualty rate. Most soldiers are now dying as a result of IEDs which are hard to find and even harder to protect against.
The sight of Union flag-draped coffins being driven through British streets has prompted growing criticism about whether enough progress is being made, whether the strategy is right and whether or not British troops are being well- protected in a conflict that still shows no sign of easing.
In many ways this could be a decisive summer. Military commanders originally pointed to the autumn or winter time as an informal point at which they would be able to measure success.
Now General Stanley McChrystal, the US military commander in Afghanistan, is believed to be talking about some time in 2010.
The prime minister admits this has been "a very difficult summer" but he also insists progress is being made. Next summer is likely to be a litmus test.
If the insurgency can be shown to have been weakened and the level of casualties reduced, then there will be optimism that the trends are moving in the right direction and a corner may have been turned in this campaign.
However, if next summer is a repeat of this one - or worse - then there are likely to be very serious questions about the current strategy and the future of the British mission in Helmand.
Add in a British general election and the US mid-term elections next year and the window of opportunity to make a difference starts to look small.
The figure of more than 200 dead is a milestone but it is ultimately a political one
Before then there will be more fighting and more deaths. This began as a battle against al-Qaeda and its protectors, the Taliban.
It was a response to the attacks on America in September 2001. British and other Western leaders insist that battle has yet to be won but is still worth fighting for.
But the scale of the conflict has grown and the nature of it has changed in the last eight years of fighting.
Other means to bring about peace are now being explored, in particular the idea of "reintegrating" some elements of the Taliban and perhaps talking to others.
The figure of more than 200 dead is a milestone but it is ultimately a political one rather than a military one.
Every soldier is a father, a son or a daughter and each death is mourned by colleagues, friends and families.
Military commanders on the ground in Helmand are confident of success but it will take more time and involve even more sacrifice.
Even if they are right, success or failure ultimately rests on the political will and the public mood back at home in the UK.