We owe it to the people of Afghanistan to repair their broken, blighted land

If the international effort there goes down, then the credibility of Nato goes with it

Iraq may have dominated media coverage of this week's Nato summit, but it is Afghanistan that provides the immediate challenge to the alliance. Despite the well publicised spat over whether and how Nato could provide military training for Iraqis, as an organisation Nato has little formal role in Iraq. It is, though, the lead body for the military force in Afghanistan. If the international effort in Afghanistan goes down, then the credibility of Nato goes with it.

Iraq may have dominated media coverage of this week's Nato summit, but it is Afghanistan that provides the immediate challenge to the alliance. Despite the well publicised spat over whether and how Nato could provide military training for Iraqis, as an organisation Nato has little formal role in Iraq. It is, though, the lead body for the military force in Afghanistan. If the international effort in Afghanistan goes down, then the credibility of Nato goes with it.

The decision reported in this paper that Britain will divert some more troops from Iraq to Afghanistan is therefore welcome. Nevertheless Afghanistan will still receive only a fraction of the resources devoted to Iraq. Member nations have put eight times the number of troops into Iraq that they have contributed to stability in Afghanistan. Donations for reconstruction to Afghanistan are a poor relation to the largesse set aside for Iraq.

The explanation for this imbalance is purely political. It has no rational basis in the relative wealth of the two countries. Iraq floats above the second largest oil reserves in the world and is - potentially at least - a rich country that can provide for itself. Afghanistan is one of the poorest nations on the face of the globe, which has not been a significant source of mineral exports since it supplied lapis lazuli for monks to illuminate mediaeval manuscripts. With the injustice that nature cruelly visits upon the poorest, Afghanistan has also been afflicted by five years of drought that have prevented some of its provinces maintaining even the wretched subsistence agriculture that keeps starvation at bay from their families.

Security is just as big a nightmare in Afghanistan. Perhaps worse. There are at least as many militias as in Iraq, and in Afghanistan they come equipped with heavy artillery and the capability for pitched battle. The majority of its population has been born since the Soviet invasion of 1979 and have no recollection of their country other than in conflict or on the brink of conflict.

Then there is the heroin trade. The opium poppy is Afghanistan's sole cash crop, its parallel to Iraq's oil reserves. This year's harvest is predicted to be a bumper crop, and two-thirds of farmers surveyed earlier this year responded that they intended to plant even more next year. Depending on whose estimate you believe, the value of the opium harvest is between a quarter and a half of the nation's entire GDP. It is not unfair to say that Afghanistan has an economy that is addicted to narcotics.

The drugs trade and warlordism are twin evils that are mutually reinforcing. Control of the trade provides regional commanders with the revenues to pay and arm their own militias, which in turn make it harder for weak central authorities to suppress opium cultivation. In the age of global communications, there are dire consequences for our own inner cities. Over 80 per cent of the heroin traded in the back streets of Liverpool, Glasgow and Lambeth began as poppies in Afghan mountain valleys.

Fittingly, given its direct impact on our society, Britain is the member of the G8 charged with responsibility for finding a cure for Afghanistan's heroin habit. Wisely, the Foreign Office and the Department for International Development have concluded that there is no realistic prospect of eradicating the opium crop unless farmers are offered a viable alternative. They have produced a 10-year programme to replace the production of heroin, which balances measures for its suppression with the promotion of economic development. A similar approach worked well across the border in Pakistan, where paying for local roads enabled farmers to replace poppies with onions for the Islamabad markets.

This has not gone down well with our partners in Washington. True to stereotype, the Bush administration hankers for a more punitive, less complex solution. Robert Charles, an assistant secretary at the State Department, recently surfaced at the Narcotics Sub-Committee for Congress to rebuke Britain for "going wobbly" and harbouring "some kind of misplaced sympathy for someone who will have to do a little bit more work" growing subsistence crops. Even by the standards of the Bush administration, this betrays astounding incomprehension of the challenges of economic survival in a country as poor as Afghanistan.

In truth, the combative approach of the White House is part of the problem in Afghanistan. The bulk of US soldiers in the country are neither peacekeeping nor enforcing the demobilisation plan for the militias, but are in the mountain ranges hunting down a resurgent al-Qa'ida and Taliban. As in Iraq, attempts to win the hearts and minds of local people are sabotaged by confusion over whether the Western military presence is there to keep the peace or to wage a war.

This confusion has now infected the humanitarian effort. This week Nato authorised the formation of more Provincial Reconstruction Teams, which bring together army detachments with aid workers. As Christian Aid has complained, this results in the humanitarian effort being identified with the military operation. Unfortunately the humanitarian work of aid workers does not compensate local people for actions by the US military in knocking down their villages and trampling their crops in the hunt for bin Laden. One malign consequence has been a sharp rise this year in the targeting of NGO staff for assassination, with the perverse result that the area of Afghanistan open to aid work has been shrinking.

It need not surprise us that Afghanistan is a challenging place to pacify. For centuries it has sustained a tradition of weak authority at the centre and strong power bases in the regions. More recently, the West pumped up the power of local commanders by flooding the country with arms to increase the casualties and cost of the Soviet occupation. It will not be easy and it will not be quick to forge the fractured country we invaded into a peaceful, cohesive state.

This in turn makes it all the more discouraging that the attention of the West wandered away so quickly from Afghanistan to Iraq. Richard Clarke, the former head of counterterrorism in Washington, has recorded in his account of the obsession of the Bush administration with Iraq that from the start they held back the bulk of their forces for the conquest of Iraq, and even redeployed those Special Forces trained in Arabic from Afghanistan.

Famously, at the end of the Afghan conflict, Tony Blair promised, "This time, we will not walk away from you." On Wednesday he was lamenting that he would have preferred to have had a larger number of troops there from the very beginning. The prime reason why a larger number were not available for Afghanistan is that Iraq is the military, political and financial priority of Washington.

When he addressed Nato this week, Hamid Karzai, the president of Afghanistan, reported that half of its eligible 10 million adults had registered to vote. That is a truly impressive percentage against a background in which residents have been shot for registering and electoral staff have been blown up for compiling voter lists. It should humble countries like our own, where often less than half the population turns out to vote even in a situation of total safety. We owe it to a people who show that degree of bravery to vote for a future for their country to offer them more than second place to Iraq.