So far this year, about 20 percent of the nation’s oil production (500,000 barrels a day) is off line because of rebel violence in the Delta region. This includes the kidnapping of 29 foreign oil workers, blowing up of pipelines and pumping stations and a bad attitude in general. The lost oil production is worth about $12 billion a year. Some 95 percent of the foreign exchange earned by Nigeria comes from oil exports. No other export even comes close.

There’s trouble in an awful lot of oil-producing regions at the moment.