We colonized Alcyone to act as a diplomatic mission to the Peloran while we placed more refueling colonies between it and Earth.  By 2250, the trip only took two years, even including the transit through The Wall.  We scattered the Pleiades Corridor with colonies big and small, and the Alliance colonies were the largest of all, fortified islands of civilization across the four hundred lightyears to the Pleiades.  It was a good thing.  We needed them later.