Illicit drug production is on the wane in Myanmar, Laos, Colombia and Peru but flourishing in Afghanistan, feeding a growing heroin market in Central Asia,Russia and Eastern Europe, according to UN drug experts.
While cocaine production is declining, the opium crop leapt in 2002 due to the ousting of the Taliban in Afghanistan.
Heroin abuse is spreading AIDS along a new trafficking route to Eastern Europe, the United Nations Office on Drugs and Crime UNODC) 2003 report shows.
The report, based on surveys, satellite images and fieldverification, is good news for the notorious "Golden Triangle", comprising Myanmar, Laos and Thailan, suggesting the region's ties with the drugs trade are being broken by efforts to promote alternative income sources for poor farmers.
But it is a blow for the Afghan government which aims to end drug production by 2013.
Afghanistan's former rulers clamped down on opium growing, but it has since flourished under the protection of warlords.
The long war against drug-trafficking in Latin America has paid off with a fall in cocaine production and a decline in the drug's use in North America, but UNODC noted that cocaine use was rising in Western Europe and South America.
Colombia, the source of three-quarters of the world'scocaine, has seen a 37 per cent decline in coca cultivation over the past two years, reversing an eight year trend, UNODC said.
UNODC estimates about 200 million people use illegal drugs - about 163 million using cannabis, 34 million amphetamines, 14 million cocaine, 15 million opiates and eight million ecstasy.