What were the conditions of Gulliver’s Liberty? What do they tell us about the emperor, his court and the politics of the land?

Gulliver is finally granted his freedom on the condition that he (1) swear to help the Lilliputians if they are ever in a war, (2) survey the surrounding land, (3) help with any building that needs to be done, and (4) deliver messages. He agrees. In return he will be granted the food and drink sufficient for 1,724 Lilliputians. This tells us that the Emperor's only interest is in power that Gulliver can give him militarily and domestically.