Peace on Earth — Stanislaw Lem

Robot armies, an arms race in space, and a brain at war with itself add up to “a futuristic version of Dr. Jekyll and Mr. Hyde” (The Boston Phoenix). 

Anxious to avoid a war that would destroy the entire planet, the major powers of Earth have come to an ingenious compromise. Each country sends a force of adaptable, self-programming robots to the surface of the moon to play out the conflict there and, hopefully, reach a mutually agreeable stalemate. But when the robots stop responding, it is up to Ijon Tichy to travel to the lunar war zone and discover what went wrong.
 
Tichy finds what he needs to know, but falls victim to an attack that severs the left and right sides of his brain: one of which knows nothing about the status of the moon, the other of which isn't telling. Now Tichy finds himself at the center of a new sort of war of attrition, with each world power clamoring for his knowledge and each half of his stubborn brain clamoring for control.
 
Wry and action-packed in equal measure, Stanislaw Lem's absurd, insightful sendup of the Cold War is required reading for any fan of science fiction. Here, “humor and a breathless pace create a delightful and thought-provoking read” (Publishers Weekly).