Why 2013 will be a year of crisis

• David Frum: The drought in the U.S., Russia and Australia is driving up food prices
• He says sharp rises in prices have long been tied to unrest among the world’s poor
• High prices have been cited as a cause of last year’s upheaval in Egypt and Tunisia, he says
• Frum: The winner of November election in U.S. will have to deal with the consequences