Daylight on Iron Mountain, Book 2, Chung Kuo

Japan lies under a radioactive cloud, its denizens wiped out. America has been subjugated, its inhabitants scattered. The Old World is dead, buried beneath the foundations of the new - Chung Kuo, a mile-high, globe-spanning megacity. Billions have perished and history has been rewritten with their blood. Over all of this one man reigns supreme: Tsao Ch'un - the Son of Heaven. But it takes one type of man to conquer a world, another to rule it. The Son of Heaven's brutality has alienated even his closest allies and in the depths of the great city, rebellion has been unleashed. The Great Wheel of Change turns and the fight for the future has begun.