What’s behind the coup in Niger?

Last week, President Bazoum, the first democratically elected president to succeed another in Niger, was detained by his own guards. A military junta is now running the country. Niger was one of the few democracies left in the Sahel. From Mali in the west to Sudan in the east, a whole swathe of Africa is now run by the military. President Bazoum was a key ally to western countries, which have denounced the coup. And tensions are rising between countries in the region, who are split over what should happen next. So, what does the coup mean for Niger and the wider region?