Talk of time to turn and flee is wrong - as long as Nato is given a boost

"Our enemies have watches, but we have time," boast the Taliban. Waiting for Afghanistan's invaders to give up under relentless harassment worked in the past. Can they wear down the natural impatience of western democracies and drain their ability to commit to years of lost lives and cash in this unforgiving landscape?This has been crisis week, with one authoritative expert report after another warning of imminent failure unless more is done better, right now. The unannounced dash to Kabul by Condoleezza Rice and David Miliband yesterday was designed to repair the damage done on both sides. British newspaper indignation at President Karzai's refusal to accept Paddy Ashdown as the UN envoy and, worse, his contemptuous remarks about British fighting in Helmand seriously risk public willingness to stay in Afghanistan. At lunch with Karzai strong words were exchanged on both sides, but he went to great lengths to apologise and, in the press conference afterwards, to complain vigorously that he was "misquoted" - which counts as a diplomatic retreat.

But Britain owed Karzai reassurances too. Karzai reads the UK and US press assiduously, watching for nuances and any signs of waning commitment. He knows Afghanistan only keeps Nato support for as long as voters consent. He read the battery of British columnists from right and left in the past week calling for immediate withdrawal, ranging from Matthew Parris and Simon Jenkins to Andreas Whittam Smith and Seumas Milne. The "out now" clamour includes those who take a Kissinger realpolitik view - let foreigners rot and sort out their own problems; do nothing unless it's in our own interest - and those who regard all intervention as latter-day colonialism and anything the Americans do as always fatally tainted. It's interesting that the armchair commentators are not supported by any of last week's alarming reports on the ground, which all warn of the danger of failure: none recommends a withdrawal that would certainly ensure that failure right now.

How bad is it? Pretty terrible. Kabul is jittery after the latest attacks on the Serena Hotel: suicide bombs against civilians are a recent horror. Opium production has risen for the past two years, providing 90% of the heroin on Britain's streets. Away from democracy, the rule of law remains largely sharia administered: the young journalist sentenced to death for downloading material on women's rights is only one example. Everywhere women are in burkas. Crime is rampant, the police are corrupt.

Three times his enemies have nearly killed Karzai, who has no deputy, no planv B if they do get him. No wonder he keeps mainly to his palace compound. The wonder is that he has survived in power so long. Next year's elections oblige him to walk a tightrope - not to be the invaders' puppet, yet knowing the fragile peace in most of the country depends on Nato. Opinion polls suggest he reflects the same understandable ambivalence shared by his people: they want the foreigners gone, but they don't want civil war and the return of the Taliban that would follow within days of Nato retreat. They know what would happen next because they have lived it all before during 30 years of war.

Condoleezza Rice greeted troops in Kandahar with the obligatory hyperbole: "You will leave an extraordinary legacy of peace, prosperity and democracy for Afghan people and in doing so a legacy of peace for the world." That's what politicians must say; but the assembled US, Dutch, British, Canadian, Turkish and Slovakian troops must know the gap between the words and life on the streets.

What's the truth? In the north things are getting better; in the south the army is winning battles in an area never governed, where Kabul's writ never ran. New roads are built, there is a vigorous free press, five times more children are in school - a third of them girls - and fewer children are dying. Some projects work while others fail. The real question is: how do you judge success? This poorest, most desolate and ungoverned place will take years to improve a bit - just enough to be an improving, not a failing, state. What counts as success here? Realpolitik might say simply denying the ground to fanatics who will turn it back into a training ground for 9/11 attacks. Common decency says we can't walk away now, not until this stricken country can survive alone.

The current strategy of training up Afghan troops to fight, withdrawing our forces to a training and support role, building capacity in the civil service, paying the salaries of 100,000 teachers and the like is slowly improving life for many. The Taliban's change of tactics to suicide bombing is largely due to losing ground in pitched battles. Loose talk of the last days of Saigon, the end of the great game, time to turn tail and flee, is wrong. But unless Nato does more now, unless there is more money, more effort, more help, then it will be true. That's what the reports warn.

But one great blundering mistake may in the end destroy all the good done elsewhere. The opium economy will always be stronger than the real economy. Only 8% of GDP comes from commerce: the rest is aid. Off the books the real economy is all opium, more and more by the year. The US wants to spray and impoverish the poorest farmers, causing hatred. The US drives the disastrous prohibition policy imposed by the UN. Unless and until the drug is given as a medicine to registered addicts, cutting demand and cutting drug-driven crime in the west, illegal opium growing will always distort and corrupt everything else here in Afghanistan. Buy it to use for morphine, buy it to destroy, but buy it at a price above the relatively low price the narco barons pay to poor farmers. Agriculture in the EU and the US has always been a strange subsidised distorted market. But there never was a better reason for buying a crop than to bring Afghan farmers in from the world of crime that risks keeping the country lawless indefinitely.

As Nato defence ministers gathered in Vilnius yesterday, Robert Gates, the US defence secretary, grew increasingly contemptuous of the feeble contribution of many Nato members to Afghanistan, sending out letters this week to each defence minister and asking for more support. Jokes about German soldiers not allowed out at night abound. The Canadians have every right to threaten to withdraw from dangerous Kandahar unless Europeans do more. It's easy to understand America's long-term frustration with Europe's refusal to pull its weight, now or back in the cold war.

Europe replies thus: the world would be in a less perilous state now if only America had listened to us. Without the Iraq disaster, how different now Afghanistan would look. If those trillions wasted in Iraq had been invested in Afghanistan aid, this poorest place on earth might already have moved up a few notches on the development charts. The Taliban would not now be resurgent. The people of Europe would be far more willing to send troops and money had America and Britain not set out on a mindless "war on terror". One way or another, both sides need to recognise their own past failings with a little humility.

Politically, the easy option would be to cut and run. Gordon Brown and his new ministers came here and asked the hard questions last year. In the end, the hard answer was that we must stay - and for a long time. It may yet fail, but trying harder is the only answer now.

Polly Toynbee