MOD:WCU:BW

The Union of Border Worlds (often simply called "the Border Worlds") is apparently an alliance of frontier-based human worlds. It is never specified whether the Union is an actual government, or a mutual defense organization between multiple sovereign planets; the fact that there is a unified military and a common uniform and insignia, however, seem to suggest the former. In Wing Commander IV, the Union is the apparent antagonist, teetering on the edge of a shooting war with the Terran Confederation, as instigated by the Black Lance. The Union of Border Worlds is allied with the Free Republic of the Landreich, although the FRL is apparently not a member.

Text taken from Wikipedia