But according to new projections from the Air Force, its initial cost will soon be dwarfed by the price of operating the facility — about $30 million a year. By 2024, when the 10-year agreement for use of the base in Agadez, Niger, ends, its construction and operating costs will top a quarter-billion dollars — or around $280 million, to be more precise.

And that's actually an undercount. The new projections from the Air Force do not include significant additional costs, such as salaries of the personnel stationed at the base or fuel for the aircraft flying out of Agadez. The facility, which is part of the expanded U.S. military footprint in Africa, is now the largest base-building effort ever undertaken by troops in the history of the U.S. Air Force, according to Richard Komurek, a spokesperson for U.S. Air Forces in Europe and Air Forces Africa.