Why was there a long war between Lilliput and Blefuscu? What does the Lilliputian emperor decided to do about it?

The people of Lilliput and Blefuscu are unable to get along because years ago, after an emperor's son was injured trying to break his egg on the smaller end (the traditional way of egg breaking), he decreed that no one may break the smaller end of his egg. This caused a great uproar among many of the Lilliputians and led to six rebellions and thousands of deaths. Eventually the Big-Endians were exiled and went to Blefuscu, where they gained favor and convinced the government to go to war against Lilliput.

When the Lilliputians and Blefuscudians go to war, Gulliver proves to be very useful by dragging the entire Blefuscudian fleet of ships to the shore of Lilliput, where "The Emperor and his whole Court stood on the Shore expecting the Issue of the great Adventure." When Gulliver arrives, he cries out, "Long live the most puissant Emperor of Lilliput!" The emperor gives Gulliver the land's highest honor, "Nardac."

Later the emperor requests that Gulliver go back to the enemy's shores and do his best to destroy what is left, turning the empire into a province. Gulliver thinks that this action is going too far and declines the request.