Welcome to the future, dear reader. There are a few things that make this world tick.
After the end of the Third World War, the surface of Earth was contaminated by the use of toxins, chemical weapons, and nuclear weaponry. The surface is no longer habitable so mankind has created giant floating nations to survive. These nations are held aloft by anti gravity generators, reverse engineered from the Martian wrecks after their failed invasion attempt. Each of these nations is named after notable rivers across the globe, including influences from their respective areas.