On 28 January, foreign ministers from around the world will gather in London for a conference on Afghanistan. The aim is to mobilise international efforts behind a plan for how to deploy military and civilian resources on the ground. The London conference will be chaired by the Foreign Secretary, David Miliband. Writing exclusively in the New Statesman this week (page 25) ahead of the conference, Mr Miliband stresses the importance of a "clear political strategy", and says: "We will be looking to President Karzai's government to show that its intentions on security and governance will be carried through into action."

The Karzai government, however, has much work to do. So, too, do Nato forces. The harsh reality is that Afghanistan continues to lack both effective security and good governance. On 18 January, Taliban gunmen and suicide bombers launched a spectacularly brazen attack in the heart of Kabul, killing five people, wounding more than 70 others and striking a blow at the image that Nato forces and the Afghan government have tried to propagate: of a country heading towards peace, calm and normality.

The truth is that violent attacks of one sort or another are common in the capital. According to one estimate, there is a "security incident" every seven to ten days, on average, in Kabul. Meanwhile, a map published last year by the International Council on Security and Development showedthat the Taliban have a "permanent presence" across four-fifths of Afghanistan - with "permanent presence" in any province defined as one or more insurgent attacks, lethal or non-lethal, a week.

The fighting in Afghanistan has intensified in recent months, but with no real security gains for ordinary Afghans. Figures released by the United Nations Mission in Afghanistan show that civilian casualties rose significantly in 2009, to 2,412 - up 14 per cent on 2008. The rise made 2009 the deadliest year for Afghans since the war began in October 2001. With President Obama's decision to escalate the war by sending in 30,000 extra troops, this conflict will become only bloodier in 2010. The coffins of dead British soldiers will continue to arrive at Wootton Bassett.

Can the Taliban insurgency be defeated on the battlefield? One of the most senior British commanders in Afghanistan is sceptical. "In terms of whether we can defeat them, no," Lieutenant Colonel Nick Kitson told reporters in Helmand this past week. "Anyone who studies counter-insurgency will know that you are not going to win by military means alone, and therefore our focus is on the population, the security of the population, and generating the pre-eminence of the Afghan government."

Yet there is little positive news on the issue of "governance", either. The Afghan government is far from pre-eminent and lacks popular support. Hamid Karzai, after all, was re-elected in a presidential election marred by the discovery of millions of fraudulent votes. He will arrive at theconference in London having failed to fill nearly half the positions in his cabinet after the Afghan parliament rejected most of his nominees. Legislators have rejected the president's picks twice this month; 11 of the 25 seats remain vacant.

Meanwhile, corruption is rampant. According to a new report from the UN Office on Drugs and Crime, Afghans have paid £1.5bn in bribes over the past 12 months - the equivalent of almost a quarter of legitimate GDP. The report found that more than half the population had to pay at least one bribe to a public official last year.

Corruption, violence, insecurity, political deadlock . . . the problems besetting Afghanistan seem intractable. And the war remains unwinnable. As Sir Rodric Braithwaite, Britain's ambassador to Moscow from 1988-92, writes in his essay on page 22, the British and the Americans have failed to learn the lessons of history in Afghanistan - in particular, the disastrous experience of the Soviet occupation of the 1980s. “In a purely military sense, the British won their wars in the 19th century and the Russians won theirs in 1979-89," he writes. "It was the surrounding politics that went wrong."

If the British government and its allies think a conference in London will resolve the political and military crises in Afghanistan, they are deluded. Listen to the outspoken Afghan MP Malalai Joya (interviewed on page 28): "I don't expect anything positive from the London conference at all. Since 2001, there have been a number of conferences. They have only pushed Afghanistan further into the hands of the occupying forces and their local agents."

She is right: Britain should be making plans to withdraw.