"However, an intriguing question escaped many observers: how on earth did Mexicans, who live in the land where corn was domesticated, become dependent on US imports in the first place?"
This is a great piece by Walden Bello in the Nation. This has been a question going on relentlessly in my head: How on earth did the Lebanese, Syrians and Egyptians who live on the land where wheat was domesticated, become dependent on wheat imports. I know part of the answer, which includes carrying capacity (there were far fewer people), possible climatic changes (less rainfall), and the abandonment of vast expanses of land, which used to be planted with grain and have now become derelict. Bello offers an additional element that has to do with free-market development policies, the destruction of peasant agriculture and speculations. The example he gives for rice in the Philippines is very thorough.
" That the global food crisis stems mainly from free-market restructuring of agriculture is clearer in the case of rice. Unlike corn, less than 10 percent of world rice production is traded. Moreover, there has been no diversion of rice from food consumption to biofuels. Yet this year alone, prices nearly tripled, from $380 a ton in January to more than $1,000 in April. Undoubtedly the inflation stems partly from speculation by wholesaler cartels at a time of tightening supplies. However, as with Mexico and corn, the big puzzle is why a number of formerly self-sufficient rice-consuming countries have become severely dependent on imports." (Thanks Rami)