Colombia, claiming damages for crops destroyed by fumigation.

Colombia has refused to halt its aerial assault, but in an attempt to do more to improve its image - and to create jobs - it has pledged to pull up 100,000 hectares of coca by hand this year. Hence the arrancadores and their army guards.

It's risky work. Some coca farmers plant bombs alongside the plants; six arrancadores were killed last year by a mine and 13 soldiers guarding the workers were shot by Farc guerillas. A fortnight ago, Farc fighters based across the border in Ecuador fired rudimentary bombs made of domestic gas tanks at arrancadores operating in border country.

The 300 men I have travelled with take about two hours to strip bare the one hectare field. It is a Sisyphean task - and they know it as well as the farmers who will replant the field as soon as they're

gone. "I hope they plant more," one of the arrancadores tells me. "More work for us, isn't it?"

In the nearby town of Pueblo Lindo a coca farmer called Manuel tells me: "I'll plant it again soon. What else can I do? The government isn't offering us any support, no money, no training, no roads. And nothing pays like this bush."

The coca bush can produce leaves in only three months - there is no legal crop like it. And the crude cocaine paste sells for $1,500 per kilo to the disbanded paras.

Until coca ceases to be profitable and a new approach is taken in countries that buy the cocaine, says Vicente Torrijos, a security analyst at Bogota's Rosario University, destroying coca by any means will only ever be a half-measure. "Eradication is an exercise in restraint of problem-limitation," he said.