The Lilliputians were at war with Blefuscu, and there was a strict order banning all contact between the two peoples. Moreover, the Lilliputians received intelligence that Blefuscu had assembled a huge invasion force to end the conflict once and for all. Gulliver says that the Blefuscudianns knew nothing about him, and so he avoided the island, for "fear of being discovered by some of the enemy's ships."
However, Gulliver, who has sworn an oath to support the Lilliputians in war, developed a plan, whereby he will seize the enemy's ships and drag them back to Lilliput. His subsequent refusal to destroy all of the Blefuscudian navy, however, lands him in hot water with the Lilliputian emperor, who hoped to conquer and destroy his enemy once and for all.