NO country has ever won a counter-insurgency campaign by military action alone, and many, like the US in Vietnam and Napoleon in Spain, have been comprehensively beaten when they tried.

As the British proved in Malaya in the 1950s and 1960s, the key to ending insurrection lies in combining battlefield defeat of the insurgents with a practical hearts-and-minds campaign aimed at improving the daily lives of the local population. If they can be convinced that they have more to gain from supporting national and international efforts on their behalf than throwing their weight behind guerrilla movements or remaining passive, the insurgency withers on the vine.

Afghanistan, however, defies conventional solutions. It is effectively a narco-state reliant on opium production and trafficking for the income of one in eight of its people.

Yet controlling the opium is central to defeating the Taliban and the warlords who undermine the feeble attempts of the elected Kabul government to extend its writ much beyond the capital city's limits.

The main barrier to a negotiated peace is that the Taliban itself is not a single, organised body with a clear chain of command. While it might be a convenient label for Western states fighting in Afghanistan, the gunmen ambushing British troops in Helmand and US soldiers in Nangahar are a complex mixture of paid mercenaries, hard- line religious zealots and armed farmers.

The warlords who control the opium trade pay a tax to the hard- core Taliban, buy off the police and bribe politicians. The cash funds weapons for the insurgents, allows them to hire fresh cannon fodder, and keeps enough powerful regime members in Kabul on the payroll to thwart Nato and US attempts to tackle poppy-growing.

On a practical level, poppies will grow in Afghanistan's climate of harsh extremes while wheat or fruit is not guaranteed to survive through drought in summer and freezing winter snows. To a poor farmer with many mouths to feed, the question of what to plant is a no-brainer. If a wheat crop fails, his children will starve. Poppy may never make him rich at his level of the drug trade, but it will provide enough money so his family can eat.

The other key issue is security. The vast majority of the Afghan population would probably support anyone who could guarantee some form of rule of law and an end to extortion by the police and banditry on the roads.

No popular support for the government of Hamid Karzai will be forthcoming until Kabul can prove that it is prepared to tackle corruption from the top down.