On Christmas day, a car full of explosives plowed into a Catholic Church in Nigeria, killing dozens of people. A radical Muslim group named Boko Haram proudly claimed credit, saying it was trying to kill Christians. As recently as 2009, Boko Haram was a local Nigerian group, bloodily crafting a state-within-a-state in opposition to Nigeria's oft-corrupt government. But today, it's affiliated with al-Qaeda, as part of a massive terror network that stretches across huge swathes of Africa, der Spiegel reports.
The network also includes al-Shabab in Somalia, and al-Qaeda in the Islamic Maghreb in North Africa, among others. The Sahara has provided the perfect base for them—it's bigger than the US, all but unpopulated, and the countries it passes through have weak and corrupt governments. In September, a US military commander warned that "if left unaddressed, then you could have a network that ranges from East Africa through the center and into the Sahel and Maghreb." Spiegel argues that "in reality, this network already exists." (Read more Boko Haram stories.)