The initial reaction of French President Nicholas Sarkozy, which was to insist that the deaths would not shake his resolve to send more troops if NATO requested them, will please the United States, which has been arguing for months for greater troop commitments from its NATO allies to contain the insurgency. But the deaths of the 10 paratroops will be a litmus test for Sarkozy's pro-US foreign policy, and his belief that Afghanistan is at the front line in the battle against terrorism. This, after all, is France's worst military loss since 1983, when 58 paratroops were killed by a truck bomb in Beirut, and certain to re-energise the public debate about whether French troops are becoming bogged down in an unending war whose aims are both unclear and unattainable.

When he controversially announced in April that he had agreed to a NATO request to send an extra 700 combat troops to eastern Afghanistan, Sarkozy warned the French public about the possibility of further casualties 14 French troops have been killed since initial deployments in 2002 but even he will be surprised that so many lives have been lost in a single incident and in an area once presumed to be reasonably safe.

Recent attacks on aid workers in Lowgar province and strikes on convoys in Wardak province, both to the south of Kabul, show the extent to which the Taliban's reach has spreading. In addition, attacks are now being mounted on convoys travelling the roads to the north and east of Kabul. Many of them have reportedly been mounted by fighters loyal to the renegade Mujahideen leader Gulbuddin Hekmatyar, who while he is an ally of the Taliban is not formally part of the movement.

Hekmatyar and his Mujahideen allies helped end the Soviet Union's occupation of Afghanistan (receiving vast amounts of American money and arms in the process) but he was labelled a terrorist by the US in 2003 for opposing the American attack on the Taliban Government in 2001. Certainly he is opposed to President Hamid Karzai, but whether his objection to the presence of US-led foreign forces defines him as a terrorist is open to debate. And that is what makes Sarkozy's argument that Afghanistan represents the key battleground in the ''war on terror'' so contentious. There is no doubt that the Taliban represent an existential threat to Afghanistan's democratically elected Government, and that remnants of al-Qaeda are still active in regions near the Pakistan border, but to suggest that the Taliban are committed to supporting international terrorism and that they will rehabilitate and reinvigorate al-Qaeda should it come to power again is unnecessarily alarmist.

Arguably, it was the America's decision to sideline all prominent political and religious leaders who'd had any dealing with the Taliban which led to the insurgency. Denied a significant role in running Afghanistan, it is hardly surprising that many Pashtuns remain sympathetic to the Taliban. The Americans thought they'd get around this problem by backing Karzai (a Pashtun who broke with the Taliban after initially supporting them) as President, but nothing can conceal the fact the Pashtun have largely been frozen out of Afghan politics.

The Americans could blunt the resistance by bringing moderate Taliban figures into the Government fold, but this would be to admit they made a mistake, and so is unlikely. That means foreign troops, including Australian diggers, are likely to continue dying there until the US and its allies come to the realisation (like many foreign occupiers before them) that, while Afghanistan can be conquered from outside, it can never be subjugated.