The African Agricultural Union

History
The UN decided to clear out and take control of central Africa towards the end of the 21st century for humanitarian reasons. All the resulting unclaimed land was annexed by South Africa before the end of the decade. Seeing that the world's population was growing, and that humanity needed a place to grow its food, South Africa made their newfound territory arable, and started renting out parts of this land to other countries. Soon afterward, Nigeria and Egypt went to war with their neighboring countries to do the same thing, but with a little bit less success, due to the vast deserts that made up most of their territories.

Government
The countries that pay rent on this land do most of the governing. The "landlord" countries only step in if the terms of a contract have been broken, which could be anything from not paying rent, to another country overstepping their boundaries.

Military
Any military forces that aren't under the landlord country's command are banned, aside from basic infantry for border patrols. But you're only in trouble if you get caught... The landlord countries' militant forces act as the main police forces within a rented land swath.

Citizens and Society
Again, it varies depending on the country that is renting that particular stretch of land. Any portion of a landlord country's territory that isn't currently being rented out is being controlled by the landlord country directly. Although most of these places have been described as virturally lawless.

Borders
South Africa owns everything east and south of Gabon. Nigeria owns everything west and south of Tunisia, and Egypt owns the rest. Madagascar is "shared" by all three countries. Land rentals are usually divided up by time zones, and given out in ten-degree lateral increments, although exceptions have been made for "jagged" borders.