If Britain had not just clashed with the US over its plans to leave Iraq, it might have been easier to avoid the rising tension over Afghanistan. But not very easy: there are half a dozen disagreements over tactics, and a longer-term distinct difference of interest.

Tension was on the cards since Tony Blair decided that Britain should take a leading role in Afghanistan, giving it a responsibility for the overall outcome that it would never have had in Iraq. From the beginning its aims and style of operation have been different from those of the US.

Washington wanted the capture of Osama bin Laden, the expulsion of the Taleban, the installation of a pro-Western government, and enough stabilisation to stop Afghanistan remaining a fountain of terrorism. Britain, early on, began using the far reaches of the vocabulary of nation-building; given its huge setbacks in the battle against the opium trade, it has begun to talk of a 20-year project.

Pursuit of bin Laden

This is a US priority, although with the failure to catch him this has turned into a more general pursuit of militants near the border. Never such a focus for Britain.

President Karzai

The US’s man. Britain has been more concerned than the US about his habit of shifting obstructive barons to other jobs instead of sacking them. To demonstrate his independence from the West, he replaced a southern governor whom Britain had found particularly sympathetic in the opium battles.

Regional governor

Britain has appeared more willing to work with amenable provincial governors, rather than through Karzai, on the grounds that centralised government has never been a big feature of Afghan life.

Spraying opium poppy crop

One of the big practical divisions. The US has broadly favoured spraying many crops to wipe them out quickly. Britain argues that this will alienate the farmers who are the best hope of getting rid of the Taleban, and that efforts should focus on stopping the drug traffickers, while giving the farmers other choices of livelihood. But Britain is under pressure after record crops this year.

Hearts and minds

Britain has put more emphasis on winning the hearts and minds of Afghans. This was a big part of the rhetoric of Lieutenant-General David Richards, head of Nato’s international security force in Afghanistan. But again, Britain was under pressure to justify its approach after the Taleban seeped back into the north of Helmand province, the heart of the poppy-growing region. General Dan McNeill, his successor, an American, has adopted a more confrontational approach, triggering a row about rising civilian casualties with Karzai.

Talking to Iran

Britain has talked to Iran about stemming the opium trade and says that it has been helpful. But the US is not on speaking terms with Iran, and has been unwilling to separate other disputes, such as Iran’s nuclear ambitions, from this one. In general,

Britain has adopted an approach that purports to be more sensitive to Afghan concerns. But the weakness is that its tactics haven’t had more success, nor are there as many tangible signs of development help as it intended. Its strongest card in the face of US impatience is that politicians have said that they are prepared for it to be a struggle lasting decades. Very likely, it will.

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