WASHINGTON — In 1672, Potosi, Bolivia, was one of the largest and richest cities in the world. Located at the base of Cerro Rico, Potosi was a hotbed of Spanish silver mining. Its operations were so prolific that "potosi" became synonymous for great riches.

Three hundred forty years later, Potosi is poor and rife with conflict. Just last month, miners barricaded all routes out of the city, trapping more than 100 foreign tourists for 20 days. It's hardly a surprise that the Bolivian press calls mining the burden of Potosi.

Latin American history is littered with tales of commodity booms gone bust like Potosi's. That the quick riches never seem to produce lasting wealth has led some to conclude that the region, like other resource-rich regions, is under a "natural resource curse."