Robert Fisk speaks of Afghanistan in 2002 and 2008. Wonders why we think we can win there?

The garden was overgrown, the roses scrawny after a day of Kandahar heat, the dust in our eyes, noses, mouth, fingernails. But the message was straightforward. "This is a secret war," the Special Forces man told me. "And this is a dirty war. You don't know what is happening." And of course, we are not supposed to know. In a "war against terror", journalists are supposed to keep silent and rely on the good guys to sort out the bad guys without worrying too much about human rights.

..."How many human rights did the mass killers of 11 September allow their victims? You are either with us or against us. Whose side are you on? But the man in the garden was worried. He was not an American. He was one of the "coalition allies", as the Americans like to call the patsies who have trotted after them into the Afghan midden. "The Americans don't know what to do here now," he went on. "Their morale in Afghanistan is going downhill – though there's no problem with the generals running things in Tampa. They're still gung-ho. But here the soldiers know things haven't gone right, that things aren't working. Even their interrogations went wrong". Brutally so, it seems.

In the early weeks of this year, the Americans raided two Afghan villages, killed 10 policemen belonging to the US-supported government of Hamid Karzai and started mistreating the survivors. American reporters – in a rare show of mouse-like courage amid the self-censorship of their usual reporting – quoted the prisoners as saying they had been beaten by US troops. According to Western officials in Kandahar, the US troops "gave the prisoners a thrashing".

Things have since changed. The American forces in Afghanistan, it seems, now leave the beatings to their Afghan allies, especially members of the so-called Afghan Special Forces, a Washington-supported group of thugs who are based in the former Khad secret police torture centre in Kabul. "It's the Afghan Special Forces who beat the Pashtun prisoners for information now – not the Americans," the Western military man told me. "But the CIA are there during the beatings, so the Americans are culpable, they let it happen." This is just how the Americans began in Vietnam. They went in squeaky clean with advisers, there were some incidents of "termination with extreme prejudice", after which it was the Vietnamese intelligence boys who did the torture.

We, of course, have been peddling this crackpot nonsense for years in south-west Asia. First of all, back in 2001, we won the war in Afghanistan by overthrowing the Taliban. Then we marched off to win the war in Iraq. Now – with at least one suicide bombing a day and the nation carved up into mutually antagonistic sectarian enclaves – we have won the war in Iraq and are heading back to re-win the war in Afghanistan where the Taliban, so thoroughly trounced by our chaps seven years ago, have proved their moral and political bankruptcy by recapturing half the country.

It seems an age since Donald "Stuff Happens" Rumsfeld declared,"A government has been put in place (in Afghanistan), and the Islamists are no more the law in Kabul. Of course, from time to time a hand grenade, a mortar explodes – but in New York and in San Francisco, victims also fall. As for me, I'm full of hope." Oddly, back in the Eighties, I heard exactly the same from a Soviet general at the Bagram airbase in Afghanistan – yes, the very same Bagram airbase where the CIA lads tortured to death a few of the Afghans who escaped the earlier Russian massacres. Only "terrorist remnants" remained in the Afghan mountains, the jolly Russian general assured us. Afghan troops, along with the limited Soviet "intervention" forces, were restoring peace to democratic Afghanistan.

The Soviet general at Bagram now has his amanuensis in General David McKiernan, the senior US officer in Afghanistan, who proudly announced last month that US forces had killed "between 30 and 35 Taliban" in a raid on Azizabad near Herat. "In the light of emerging evidence pertaining (sic) to civilian casualties in the ... counter-insurgency operation," the luckless general now says, he feels it "prudent" – another big sic here – to review his original investigation. The evidence "pertaining", of course, is that the Americans probably killed 90 people in Azizabad, most of them women and children. We – let us be frank and own up to our role in the hapless Nato alliance in Afghanistan – have now slaughtered more than 500 Afghan civilians this year alone. These include a Nato missile attack on a wedding party in July when we splattered 47 of the guests all over the village of Deh Bala.

And Obama and McCain really think they're going to win in Afghanistan – before, I suppose, rushing their soldiers back to Iraq when the Baghdad government collapses. What the British couldn't do in the 19th century and what the Russians couldn't do at the end of the 20th century, we're going to achieve at the start of the 21 century, taking our terrible war into nuclear-armed Pakistan just for good measure. Fantasy again.

Joseph Conrad, who understood the powerlessness of powerful nations, would surely have made something of this. Yes, we have lost after we won in Afghanistan and now we will lose as we try to win again. Stuff happens.