The Treaty of Sirius was an agreement which was signed by the Kzin and Earth following the end of the Earth-Kzin Wars. The treaty ordered the complete demilitarization of the Kzin, and only a small police force was allowed to operate. Another clause was that Earth, and later the United Federation of Planets, were allowed unrestricted access into Kzinti territory. (TAS episode: "The Slaver Weapon") In the 2290s, representatives from the Bureau of Interplanetary Affairs were discussing and renegotiating the terms of the treaty with the Kzinti. (TOS - Crucible novel: The Fire and the Rose)