Looking into why Chad is so Chad. Found couple of books, but these two sounds the most spot on. I read The Roots of Violence. The titles of the first three volumes are also intriguing:
1. Fouding and Warfare: Selected Works of Keith F. Otterbein (I dunno who is he, I dunno if it's a shame or not)
2. Studying War: Anthropological Perspectives
3. Troubled Times: Violence and Warfare in the Past
I might try and get them (on libgen).
Problem is it was published in 1998 and in the past decades lots of water flowed down the Danube. For example the book mentions oil was "recently" (in the '90s) found in Chad, but doesn't know about what happened since then, that the oil took over the cotton's place as chief export product/resource.
Chief characteristic of Chad is the constant state of war since the '60s, essentially participating constantly in armed conflicts, internal or external, everything.
As I mentioned at the Central African republic, it is a very "diverse" country with over 80 ethnicities. Chad goes further with over a 100, some most likely undocumented. The most prominent groups, the southern Sara and the northern Arab clans and tribes arrived here late, in the past 500 years. In contrast the region's history reaches back to 3000 BC to the Sao civilization, who built fortified walled settlements. The prehistory and history (actually everything researchable) is poorly researched due to the constant conflicts, and the general lack of interest. Most what was written was done by Frenchies, with their biases.
One more interesting thing to note. Nowadays the population of Chad is 16 million. In the 90's this was 5,5 million. The fuel of perpetual conflict isn't a war for resources, they can feed 16 mils now, they could 5 mils back then, still they did nothing but war.