The Afghans are desperate for international help, but describe their opposition to drug cultivation purely in religious terms.

At the State Department, James P. Callahan, director of Asian affairs at the Bureau for International Narcotics and Law Enforcement Affairs who was one of the experts sent to Afghanistan, described in an interview how the Taliban had applied and enforced the ban. He was told by farmers that ''the Taliban used a system of consensus-building.''

They framed the ban ''in very religious terms,'' citing Islamic prohibitions against drugs, and that made it hard to defy, he added. Those who defied the edict were threatened with prison.

Mr. Callahan said that in the southern provinces of Kandahar and Helmand, where the Taliban's hold is strongest, farmers said they would rather starve than return to poppy cultivation -- and some of them will, experts say.

In parts of Nangahar province in the east, where the Taliban's hold is less complete, farmers told the visiting experts that they would flee to Pakistan or risk illegal crops rather than watch their families die.

The end of opium poppy cultivation in Afghanistan has come at a huge cost to farmers, Mr. Callahan and Mr. Casteel said. The rural economy, especially in the usual opium-poppy areas, had come to rely on the narcotics trade. ''The bad side of the ban is that it's bringing their country -- or certain regions of their country -- to economic ruin,'' Mr. Casteel said. ''They are trying to replace the crop with wheat, but that is easier said than done.''

''Wheat needs more water and earns no money until it is sold,'' Mr. Casteel said. ''With the opium trade they used to get their money up front.''