Childhood's End (1953) by Arthur C Clarke

Wikipedia wrote:Childhood's End is a 1953 science fiction novel by the British author Arthur C. Clarke. The story follows the peaceful alien invasion of Earth by the mysterious Overlords, whose arrival begins decades of apparent utopia under indirect alien rule, at the cost of human identity and culture.

Clarke's idea for the book began with his short story "Guardian Angel" (1946), which he expanded into a novel in 1952, incorporating it as the first part of the book, "Earth and the Overlords". Completed and published in 1953, Childhood's End sold out its first printing, received good reviews, and became Clarke's first successful novel. The book is often regarded by both readers and critics as Clarke's best novel, and is described as "a classic of alien literature". Along with The Songs of Distant Earth (1986), Clarke considered Childhood's End one of his favourite own novels. The novel was nominated for the Retro Hugo Award for Best Novel in 2004.

Wikipedia wrote:Men called them Overlords
They had come from outer space—
they had brought peace
and prosperity to Earth
But then the change began.
It appeared first in the children
—frightening, incomprehensible.
Now the Overlords made their announcement:
This was to be the first step
in the elimination of the human race
and the beginning of—What?
—Original back cover quote, paperback edition

Wikipedia wrote:In the late 20th century, the United States and the Soviet Union are competing to launch the first spaceship into orbit, to military ends. However, when vast alien spaceships suddenly position themselves above Earth's principal cities, the space race is halted forever. After one week, the aliens announce they are assuming supervision of international affairs to prevent humanity's extinction. As the Overlords, they bring peace, and they claim that interference will be limited. They interfere only twice with human affairs: in South Africa, where sometime before their arrival Apartheid had collapsed and was replaced with savage persecution of the white minority; and in Spain, where they put an end to bull fighting. Some humans are suspicious of the Overlords' benign intent, as they never appear in physical form. Overlord Karellen, the "Supervisor for Earth," speaks directly only to Rikki Stormgren, the Finnish UN Secretary-General. Karellen tells Stormgren that the Overlords will reveal themselves in 50 years, when humanity will have become used to their presence. Stormgren smuggles a device onto Karellen's ship in an attempt to see Karellen's true form. He succeeds, is shocked and chooses to keep silent.