Black Star Rising
It's the late twenty-first century. The USA and the USSR have destroyed each other in a catastrophic nuclear exchange, and China now rules the Americas. Then a mysterious alien spacecraft approaches Earth and demands to speak to the President of the USA. There's been no such person for decades; but the aliens won't take no for an answer, and vaporize a Pacific island to prove it. A puppet President must be found to go into space and placate the aliens.
Pettyman Castor, a humble rice-cultivator from the Heavenly Grain Collective in Mississippi, is chosen to play the part, and the peasant turned President is soon on his way to an alien galaxy - and the bizarre revelation that awaits him there will turn his world inside-out.
Frederik Pohl
Frederik George Pohl, Jr. (1919-2013) was an American science fiction writer, editor and fan, with a career spanning over seventy years. From about 1959 until 1969, Pohl edited Galaxy magazine and its sister magazine If, winning the Hugo for if three years in a row. His writing also won him three Hugos and multiple Nebula Awards. He became a Nebula Grand Master in 1993.
Frederik Pohl used these pseudonyms: Edson McCann, Jordan Park, Elton V. Andrews, Paul Fleur, Lee Gregor, Warren F. Howard, Scott Mariner, Ernst Mason, James McCreigh, Dirk Wilson, Donald Stacy and James MacCreigh.