With the deaths of six British soldiers in Afghanistan the number of UK troops killed since the conflict began has passed 400. Channel 4 News Chief Correspondent Alex Thomson assesses a decade at war.

The tragedy of war in Afghanistan. (Getty)

A decade drags by; America's longest war, more than 400 British military lives lost, mileposts on a journey the destination of which shimmers then vanishes like a Helmandi desert mirage. A war in which the west got lost many years back and now has no idea where it is going - except out and home as fast as it can.

Thinking about this war brings to mind that apocryphal signpost which, legend has it, stands on some Yorkshire Moor and says: "Please do not throw stones at this notice." As an epitaph to yet another war the west has started and lost in Afghanistan, it encapsulates the pointlessness of a war we have fought for many years now, simply because our presence causes the war to exist.

Click for data: UK war dead in Afghanistan - Interactive timeline

Nobody pretends - even in the Pentagon - that the Taliban, the Haqqani network, the Hisb-e-Islamia and all the other aspects of the Afghan resistance, are anything but domestic franchises, even after the death of Osama bin Laden, the weakening of al-Qaeda and repeated overtures from Mullah Omar hinting that a Taliban incorporated within the government of Afghanistan would not threaten the outside world by harbouring terrorists.

The Taliban wish to bomb London about as much as the Women's Institute wants to invade China.

Sure, they plan, arm, re-equip and enjoy political patronage across the Durand Line in nominal Pakistan - but they seek only power within Afghanistan itself. The nationalist cause is stronger to most than the view that the invaders are infidels. Most in the Taliban wish to bomb London about as much as the Women's Institute wants to invade China. Never did. Never would.

All resistance groups in Afghanistan have said to me and many others (including our governments) that they have no wish to kill British forces except insofar as the British invaded and still occupy their country and their land.

In short, one of the main reasons to fight this war; the presence of Osama bin Laden in Afghanistan and its harbouring of al-Qaeda, has largely gone, and many argue that the war continues simply because Britain and Nato are there to fight one. By contrast this makes Vietnam look like a strategic imperative: at least the US could say it was fighting an ideology there, right or wrong.

Few in Nato, Washington or London these days even try to justify the Afghan disaster in terms of fighting any threat to our cities. The original justification of eradicating al-Qaeda has long been achieved. Of course most of the job could have been done via drone attacks anyway - but all that was lost in America's headlong ground invasion and obsession with hunting down Osama bin Laden.

It could probably have been done without invading a country at all. But after September 11 the US government was not going to take any path but invasion.

In the early years of the war, Afghanistan was left in a kind of half-hearted limbo. There were not enough soldiers, not enough investment, not enough rebuilding - and critically this gave the resistance groups time, money and the opportunity to regroup in Pakistan and across the south and east of Afghanistan.

When they came back they found British forces in puny numbers in provinces like Helmand. Under-equipped, defending remote "platoon-houses", small forts under constant attack.

More from Channel 4 News: IEDs - the invisible enemy

Then defence secretary John Reid's forlorn hope that the British mission could be completed "without a shot being fired" by now sounded naive, that of a man who knew little about Afghans, Afghanistan and Britain's bloody history of meddling in the country. This was matched of course, by British tactics on the ground. As the British abandoned their hopeless "platoon houses", the resistance honed their tactics. This became the war of the IED (improvised explosion devices) - roadside bombs.

Then came IEDs with shaped-charge technology. Then with armour-piercing capability. We would find ourselves one long day in the Nad-e-Ali district (supposedly heroically cleared of insurgent forces months earlier) on a road with so many buried bombs they couldn't defuse them all in a day.

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Not only that, the bomb-makers were now perfecting devices with so few metal parts that handheld bomb-detectors were having difficulty finding them at all. All the while military minders would try to direct TV cameras endlessly at their latest QIP - Quick Impact Project. The sheer, staggering naivity smacked you in the face every time. The concept was that paving a road or rebuilding a school would have a "quick impact" and bring the Afghans to see that the invaders were a force for good.

Photo gallery: Channel 4 News in Afghanistan

So here's the well we've dug, here's the school we've opened, here are the hearts and minds we've won. It never seemed to occur to anybody (or rather nobody is ever allowed to admit) that whilst heavily armed infidel alien soldiers invade and occupy your land by force you cannot - per se - win hearts and minds.

Moreover, those same invaders continued to kill civilians in airstrkes and continued to conduct the hated "night-raids", turning over families' homes in the dead of night - a grave invasion of Pashtun notions of privacy.

So a grinding decade on, of course people use new wells and even schools - but they also snipe and bomb the foreign soldiers out on their patrols even as Nato talks to the resistance leaders and promises to leave their land by the end of 2014.

The British plan to somehow win over "moderate Taliban" lies in tatters, because it fundamentally failed to understand what the Taliban are, how they function. The fact is that the Taliban brought the one thing Afghans, like all of us, crave above all else - security.

And every year more civilians are caught in the crossfire and killed by the resistance and Nato alike.

The tragedy of war in Afghanistan. (Getty)

In the Pashtunwali - the Pashtun areas of southern and eastern Afghanistan (and in much of the rest of Afghanistan) people don't care very much for the benefits of bi-cameral parliament. They don't care that much about girls being educated. Security, sharia, tribal ways and loyalties - these are the things which bind people together.

Afghans also, across the country, do not much buy into the western idea that the Taliban were notably repressive. They know the northern mujahadeen (now basically the government) pulverised their country and engaged in notable episodes of mass-murder. The same murderers now have power, influence and bleed the country dry to line their pockets daily. Afghans see it. Afghans hate it.

The Kite Runner image of the Taliban is often scoffed at by Afghans. In truth the Taliban were no more or less brutal than the host of other tribal leaders and alliances which wrecked Afghanistan.

The Kite Runner image of the Taliban, widely acknowledged in the west, is often scoffed at by Afghans. In truth the Taliban were no more or less brutal than the host of other tribal leaders and alliances which wrecked Afghanistan over 20 years or so before the Taliban drove into Kabul.

The kleptocracy which passes for government, the swamping of old Afghan culture by new addictions of opium and heroin, the eroding corruption involved in getting anything done here. Small wonder the insurgents' sharia solutions are remembered often with nostalgia, not horror.

Which brings us to Nato's only real idea for getting out of Afghanistan: Afghan army and police. It is true they are better than they were, but every opinion poll shows Afghans do not believe either police or the Afghan army will hold the line, come 2014. Nor do they trust them even now.

Fears about the capacity of Afghan army and police to cope post-2014 and Nato's exit have only been heightened in recent weeks. An American proposal to cut the size of Afghan security forces by more than one-third after 2014 could lead to catastrophe, according to the country's defence minister. Few in the country would seek to differ.

The idea was first floated at the Nato conference in Brussels in February and would see Afghan army troop levels fall from 352,000 this year, to 260,000 shortly after 2014. With America largely footing the bill into the forever on this one, it is not clear if this is electioneering writ large or actually a serious proposal to cut the financial strain of Afghanistan after all the years. all the billions. But the insurgency must simply be relishing the very idea.

That lack of confidence hardly shored up by Nato's breathtaking cackhandedness of recent weeks. In the space of 48 hours recently we had US Defense Secretary Leon Panetta saying the US would stop fighting a year earlier than anyone expected. Within hours Nato Secretary-General Anders Foch-Rasmussen was saying no, everyone fights on until the end of 2014. Meanwhile the French are already leaving a year early. And the Brits seem to think they'll fight on. Somehow. It is no way to run a war.

Read more: British forces in Afghanistan - why are we there? 

Of course we in the west will simply wait and see what the truth of it all is. We are not ordered to die for a cause which no longer exists. More important than British soldiers who know what they're signing up for, is the future for Afghans themselves who never signed up for anything and want to run their country themselves in safety.

Some Afghans are not waiting however. By UN figures asylum claims have trebled in three years. Across Kabul, Afghans are moving back into their own ethnic areas, fearing what may happen when Nato leaves. In Kabul, in the shell-splashed ruins of the palaces and civic buildings, there are too many reminders of the chaos unleashed, the last time a western superpower lost a war in Afghanistan.

It is in this context that over 400 young British lives have been lost - thousands more horribly maimed for life. With each passing day it is ever easier to know how many have given their lives - but ever more difficult to say why.

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