Updated map with fixed capitals
First map in a series called Whalefall, the plot is basically that in the mid 2020s the USA collapses hard, sparks a chain of events that drags most other nations into civil wars, and is reunited by communists, but only after fighting reduces almost all cities to rubble. In universe, the map in question is made by the International Socialist Federation, the successor to the UN. Most nations in it don't go through nearly as much as the FAC does, however. More details are in the map text.
Rwanda I'd assume
Yeah, I'm seeing that got to 40% of the population fled or killed. But
this is closer to 60%
in a massively larger country
with far more difficulty to leave, physically