Traub focuses on Guinea-Bissau. GB's population is 1.6 million and its per capita GDP is about $480. It was once part of the empire of Mali.
About two years ago, I read an article about the west African drug trade phenomenon; that piece also emphasized Guinea-Bissau. It sounds like the problem has continued to worsen. Traub analogizes GB and other African states to Afghanistan in terms of their providing ungoverned havens for criminal activity.
Here's a really well-written paragraph from his article that clearly summarizes the issue:
"The dynamic before which Guinea-Bissau and its neighbors along the West African coast are truly helpless is globalization, which ensures that producers will find a way to deliver all things insatiably desired, whether good or bad. West Africa, which neither produces nor consumes significant quantities of cocaine, is a victim of changes in global supply and demand. Partly because of heightened American and South American efforts in recent years, the flow of cocaine to the United States diminished. Traffickers increasingly turned to Europe, where cocaine use grew significantly over the last decade. European law-enforcement officials responded by cracking down on air and maritime routes from South America. And the traffickers in turn adapted by establishing the West Africa connection."