Golding himself describes the theme of Lord of the Flies "as an attempt to trace the defects of society back to the defects of human nature" (qtd. in "Notes on Lord of the Flies" 204). Ralph, Jack, and the other boys on the island serve as a microcosm for the adult world and World War II. In many ways, Golding uses the boys' conflicts to prove the innate evil nature of man, reinforcing the idea that the redeeming qualities of any civilization depend on the individual and their sense of ethics and morality.
The evil of the island absolutely correlates to the greater evil of the outside world and World War II. At the very end of the novel, the naval officer interrupts the man hunt for Ralph, abruptly ending a search that would have undoubtedly ended in Ralph's death. With this being said, the naval officer rescues the children to take them away in a cruiser which will "presently be hunting its enemy in the same implacable way. And who will rescue the adult and his cruiser?" ("Notes on Lord of the Flies" 204)
"Notes on Lord of the Flies" by E.L. Epstein is found at the end of my copy of Lord of the Flies.
Golding, William. Lord of the Flies. New York: Perigree Books, 2006.