Afghanistan is the size of Texas and half the area is above 5,000′. Opium poppies are a major cash crop and the terrain consumes any empire that makes the mistake of wandering into this land.
Somalia is also the size of Texas but at 1,800 miles its coastline is longer than that of all the U.S. states on the Gulf of Mexico. The largest cash crop here seems to be pirates.
Mali is about the size of Aghanistan and Somalia combined. There isn’t an easily transportable cash crop like the Afghan opium, there isn’t a busy shipping lane in the area like the Gulf of Aden.
The unrecognized state of Azawad is the area north of the thin blue line on the map, which is the Niger river. This is the Sahara, fairly flat and almost devoid of vegetation.
The area is almost devoid of people as well. Azawad has about the same geographic area as Texas, but it has fewer people than the city of San Antonio.
There isn’t anything to grow or mine, there aren’t any trade routes to pillage. There aren’t any mountain hideouts, there isn’t even a forest canopy to conceal comings and goings, and the population is tiny. Mali’s breakdown is a problem in the country itself, for its immediate neighbors, and for the region in general, but it lacks any of the features required to make it as much of a headache as Somalia or Afghanistan.