Mauritania maybe the nastiest place on the planet
Afghanistan previously had the distinction of being the nastiest place on the planet but Mauritania took over after the Taliban were expelled. This coup doesn't mean diddly. Mauritania was at rock bottom before the coup.
If al Qaeda sets up shop in Mauritania (virtually certain) then the U.S. will have to address that hell hole. However it would be better if an African multinational force dealt with it (fat chance).
Gary