By Alastair Leithead
BBC News, Kabul
Nato's request for more troops is key for places like Helmand
It has been a bloody six weeks since the Nato-led force in Afghanistan took control in the south of the country, and now it seems its call for more support is falling on deaf ears.
The International Security Assistance Force (Isaf) is about 20,000 strong, and half is in the south, where the fighting has been intense.
Since 31 July, when the flag was handed over from the US-led coalition to the commander of Isaf, Lt Gen David Richards, 23 soldiers have been killed in action and a further 14 lost on board the British aircraft that caught fire over Kandahar. Others have died in accidents.
In Helmand, the British troops are facing a daily bombardment as they defend small district centres from "wave after wave" of Taleban attacks, to quote the commander of British forces.
In Kandahar, Operation Medusa, which is being led by the Canadians, claims to have killed more than 500 Taleban fighters in less than two weeks.
US special forces are also making progress, moving through known Taleban strongholds.
Gen David Richards: "If I had more I could do more"
But Isaf wants more troops and aircraft.
Gen Richards has always been careful to avoid saying his forces are "overstretched", but he has also clearly emphasised the impact of not having the troops needed to take the fight to the Taleban.
Having more resources, he argues, could help reduce the number of international soldiers being killed.
"If I had more I could do more," has been his mantra, but it is clear this is becoming more pressing, as the Nato supreme commander has requested 2,500 reinforcements from Nato nations.
Some of these requests are new - a 1,000-strong battle group to help launch more operations like Medusa and make the force more mobile, the commanders argue.
But only 85% of the pledges made by member countries and 11 supporting nations have actually arrived in Afghanistan.
All 26 nations agree the resources are needed, but finding a country, or countries, to commit their citizens to the war raging in southern Afghanistan is the tricky bit.
The Canadians, British and Dutch are bearing much of the burden in the south, and the US forces, also about 20,000-strong, are providing much-needed air support and back-up, despite their operations in the east of the country, which are also pretty intense.
So Isaf has to look elsewhere.
'Hearts and minds'
Germany has a few thousand troops in the north of Afghanistan, but their rules of engagement prevent them from being moved into combat in the south - and the indication is that that is unlikely to change.
US troops face their own intense operations in the east
Other nations are also holding back, concerned by the possible human and political ramifications of moving into a war zone.
Critics have questioned whether throwing more troops into the crucible will win the war.
This mission was supposed to be about helping the Afghan government bring security, then rebuilding and developing - "winning hearts and minds".
But it has become far more about fighting. Security has turned out to be a lot harder to achieve against a determined, fearless and numerous Taleban force.
The fighting has been so intense that "rebuilding" has suddenly been added to the list of things Isaf intends to do once it has found the elusive "security".
Rules of engagement prevent German troops moving south
Nato commanders do believe they are winning, however, and ask that they be given a chance to prove how effective the force is. It has only been six weeks since they took over the south, they say.
But Canadian and British troops have been in place a lot longer, and the latter have perhaps even hindered the mission by scattering to small district centres and ending up defending against a remorseless barrage of attacks.
The extra troops, it is argued, would allow the current gains to be amplified and strike an even harder blow against the resurgent Taleban.
There is a Nato Standard Force Generation Conference on Wednesday in Mons, Belgium, where representatives from each nation will be asked to dig deep and contribute servicemen and women to the effort.
The indication from other Nato meetings this week is that most representatives will be looking at their feet and twiddling their thumbs when those countries prepared to commit forces are asked to raise their hands.
If all else fails, Britain could well be asked to commit even more troops to Afghanistan - having already added 1,000 to the original designation - and there will be serious political fallout if that is pursued.
Every foreign force that has entered Afghanistan has eventually been driven out with its tail between its legs - everyone here says the Nato mission cannot be allowed to fail.
But as a young, professional Afghan woman told me on the fifth anniversary of the 11 September attacks on the US: "We just don't know yet which way it's going to go."