Prohibition of Interference. Book 1

Lieutenant Irs' squadron of space fighters guards the scientific base of a highly advanced space civilization stationed on the Moon. Scientists at the base are researching an evolving civilization on planet Earth.
However, a rebellion breaks out in the republic, which owns the lunar base, and this revolt quickly escalates into a full-scale civil war. The base is attacked by a rebel cruiser, which destroys it, but also dies in the battle itself.
Irs is the only survivor. His fighter jet is damaged, and he has no choice but to land on Earth, where World War II has already begun.