Robert G. Mugabe has ruled over this battered nation, his every wish endorsed by Parliament and enforced by the police and soldiers, for more than 27 years. It appears, however, that not even an unchallenged autocrat can repeal the laws of supply and demand.

Bread, sugar and cornmeal, staples of every Zimbabwean’s diet, have vanished, seized by mobs who denuded stores like locusts in wheat fields. Meat is virtually nonexistent, even for members of the middle class who have money to buy it on the black market. Gasoline is nearly unobtainable. Hospital patients are dying for lack of basic medical supplies. Power blackouts and water cutoffs are endemic.

Manufacturing has slowed to a crawl because few businesses can produce goods for less than their government-imposed sale prices. Raw materials are drying up because suppliers are being forced to sell to factories at a loss. Businesses are laying off workers or reducing their hours.

Private doctors say that diseases of poverty, including tuberculosis and malnutrition, are starting to appear among their patients, including the minority whites who once were part of the wealthy class.

“Considerations of color have begun to blur very much,” said one Bulawayo doctor whose average client is a white business manager. “White people will tell you, a little embarrassed and shy, that they’re eating nothing but sadza,” or cornmeal porridge, the doctor said. “They’ve been reduced to the diet of the rural poor.”

The World Food Program issued an urgent appeal Wednesday for $118 million in donations to feed Zimbabweans, stating that drought and political upheaval would empty the organization’s stockpiles by year’s end without more money. The organization now feeds about 300,000 Zimbabweans and has regularly given food to as many as four million citizens at the height of the hunger season, in January.