So far, Islamic terrorists do not seem to be flocking to the area. Iraq is still a big draw, despite the high death rate among the Islamic terrorists who show up. Those now deterred by this are instead going off to Chechnya (where the danger is about as great as in Iraq), or Afghanistan (ditto, at least for Arabs, who are not liked much by the locals). Why the reluctance to move into what should be terrorist-central? The main reason is that there's no there there. Or at least not much. The Horn of Africa region is poor in all manner of resources that Islamic terrorists find essential. Things like lots of roads, airports, Internet connections, banks and local warlords you can do business with. The leadership in the area doesn't really want any Islamic terrorists around. Too much potential trouble with all those Western soldiers up in Djibouti. While the people in the area tend to be Islamic conservatives, they are also quite poor, and have much to loose if Islamic terrorists move in. Some of the locals have sworn allegiance to al Qaeda, but nothing much has come of it, what with the regional hostility to that sort of thing. Indeed, most of the locals have shown more enthusiasm for capturing or turning in Islamic terrorists, and collecting rewards.
Why has the United States, and some of its NATO allies (especially France, Britain and Germany) been doing with the several thousand troops stationed in the Horn of Africa. The troops are based in Djibouti, but are keeping an eye on the entire region (so called because Djibouti looks, on a map, like a "horn" coming out of Africa) because they anticipate that, as Iraq is pacified, the Islamic radicals will seek safe havens and new battlegrounds elsewhere in the arc of instability in the Middle East. The region to which they are most likely to head, in CENTCOM's view, is the Horn of Africa, where large areas are not effectively controlled by central governments or, such as in Somalia, where there has been no functioning central government for over a decade. Sudan, for example, is run by a bunch of Islamic fundamentalists and most of the East African coast is poorly policed and contains a significant Arab minority population. The eastern end of the semi-desert Sahel region, just below the Sahara desert, plugs into the Horn of Africa, and has long been the hideout of all sorts of desperadoes.