The Horn of Africa, Somali, is war-lord prone, given to the battle craze for many long years and will not give this stance up going into times of hardship. They will become mercenaries, on the rove. This will force their neighbors in Ethiopia and Kenya to defend themselves, and not in a polite manner. The outcome of these types of battles, in normal times, depends upon how well supplied an army is, but in lean times migrating mercenaries do not fare well. They are used to living on looting, what they can commandeer with guns and by being ruthless brutes, their reputation pressing all who hear them coming to lay out the goods before confrontations emerge. But in lean times, where death is the outcome for those about to be looted, something else emerges - resistance. Communities and their livestock disappear, and the marauders find little to feed themselves and fall to infighting among themselves. Thus weakened, they are picked at from the bushes along roadsides, until the remnants falter and fall. Such a process may take years, even decades, but the outcome is certain.
Note African Rift Valley commentary.
Note 7 of 10 Plate Movement commentary.
Note Red Sea 7 of 10 commentary.