Both Chad and Sudan deny arming rebels in each others countries, but that's what appears to be still going on. Both countries contain ethnic Arab and black African tribes, and these tribes have never gotten along. The situation is worse because the Arabs tend to be nomads, with herds of camels, horses and other animals, while the black Africans tend to be farmers. When there is drought, as there has been for the past few years, the Arab nomads must either try and take farmland for their herds, or lose their animals. Meanwhile, in Chad, with dozens of Arab and African tribes, there has rarely been any real national unity. The current government is basically a loose coalition of tribes, held together, barely, by president Habre.
November 1, 2006: Senegal has agreed to try former (1980s) Chad dictator, Hissene Habre, who has been living in exile in Senegal. International war crimes tribunal had indicted Habre, and finally convinced Senegal to join in the prosecution. This has got to be disturbing for the current president of Chad, Idriss Deby, who has not behaved much better than his predecessor, Habre.
October 31, 2006: Arab tribesmen from eastern Chad and Sudan are now raiding black African farming villages up to 100 kilometers from the Sudan border. The raiders kill, loot and tell the survivors to flee, so that Arab tribes can move in.
October 30, 2006: In southern Chad, more refugees from the Central African Republic (CAR) crossed the border, after over a hundred CAR rebels took a town near the Chad border.
October 27, 2006: Niger has agreed not to expel a tribe of Chadian Arabs, who had arrived as refugees, from the Chad civil war, in the 1980s. The Chadian Arab nomads had clashed with Niger farmers (who are black Africans.) This pattern of Arab nomads fighting African farmers is the same in Sudan and in Chad. No one is sure how many Chad Arabs are in Niger. Estimates range from a few thousand to over 100,000. The Chadian Arabs have promised to behave in the future.