A Bolivian soldier helps destroy an illegal coca field in a rural area. DAVID MERCADO (REUTERS)

The coca leaf, the unrefined source of cocaine, holds special significance for leftist Bolivian President Evo Morales. A former cultivator of the plant himself, Morales was swept into office in 2006 with the backing of Bolivia's cocaleros movement, a syndicate of coca-growers' unions Morales has helmed for decades.

Since then, his defense of his countrymen's right to grow the leaf, which is considered an illegal substance under the 1961 UN Single Convention on Narcotic Drugs, has brought him into conflict with the United States, which is seeking to eradicate coca production in the Andean region.

Morales' tenure has seen the establishment of an intensely nationalistic, left-leaning government whose ambitions lie in the installation of a uniquely Bolivian brand of "Andean capitalism," and whose support base is firmly rooted in the largely agrarian indigenous population.

As president of Bolivia and leader of the cocaleros, Morales has remained true to his constituency, having instituted a policy of "Yes to Coca, No to Cocaine" (Coca Sí, Cocaína No). Under the policy, the cultivation of coca for legal purposes has been expanded while the Bolivian government has beefed up efforts to crack down on the illegal production of cocaine. At the same time, Morales has lobbied for international acceptance of the coca leaf, citing its important role in Andean culture and its medicinal and nutritive qualities.

"The coca grower is not a drug-trafficker just as the consumer of the coca leaf isn't an addict," Morales said in a recent EL PAÍS interview.

Bolivia is the world's third-largest producer of cocaine, and has long been a focus of US efforts in its so-called war on drugs. The Andean nation's drug policy has angered Washington: the Morales government officially devotes 12,000 hectares to the cultivation of a plant classified internationally as an illegal substance. In reality, up to three times that amount of land is used to cultivate the leaf so it can be turned into cocaine and sold in the United States.

Morales reiterates that coca leaf is not cocaine, just as wheat is not beer and grapes are not wine

In recent years, Washington has shifted away from its policy of complete eradication of the plant, endorsing alternative development programs. Yet the success of these programs, which subsidize farmers who choose to suspend their cultivation of coca in favor of other crops, has been limited. Coca is far more cost-effective than alternatives such as coffee and rice, which are more labor and land intensive.

According to the US State Department's 2011 International Narcotics Control Strategy Report, although significant eradication efforts have been made under the Morales administration, they "have not resulted in a net reduction in the cultivation of coca." Illegal cocaine production in Bolivia has held steady at an estimated 195 tons annually, the report states.

There is little information on the amount of coca leaves Bolivia needs to meet internal demand. So far the government has refused to release the results of a study into coca leaf production and consumption in 2008, which was financed by the European Union.

Morales, who expelled the US ambassador and drove DEA agents from the country in 2008, has done little to assuage Washington's fears of increased trafficking. But what Washington calls a warranted effort to cut the hemisphere's flow of cocaine off at its source, Latin American leaders, like Morales, see it as an attempt on the part of the world's largest consumer of cocaine to bully them into footing the bill for a US domestic problem. For Morales and many other people in the region, the idea of scaling back cultivation of a potentially lucrative and culturally significant resource makes no sense. As long as Washington continues to push for eradication in accordance with the failed war on drugs, Morales will continue to be a thorn in its side.

But the Morales administration insists that it is doing its part in eradicating illegal fields. Last year, a special force destroyed more than 5,000 cocaine laboratories, 6,500 soaking holes, and 25 labs where the crystallization process is completed, according to Defense Minister Felipe Cáceres.

Morales reiterates that coca leaf is not cocaine, just as wheat is not beer and grapes are not wine. A country's millennia-old heritage must be respected while Bolivia opens the doors to a large and previously untaxed area of the market, he says.

Still, Washington is not convinced, just as it wasn't 100 years ago when the then-US ambassador to Bolivia complained about the habit and suggested that Bolivians might do better to chew gum instead.