Universal Alliance of Nations

Terran Powers was a collective term to refer to 28 major galactic powers originally and in-nature from Earth. Earth sphere was another word used to describe them, although it was rarely used.

When men began walking among stars on legs of fire and steels, 28 powerful confederations arose in 22nd century, replaced much of the old worlds. Though they weren't perfect, for several next decades, they were the essentially peacekeepers, driven forces and order protectors, replaced a now grumble and deformed United Nations, which was reduced into nothing but a small organization, responsible only to a few thousands small nations and protectorates, scattering on Earth, our solar system and 800 light years around it.

The major galactic Earth-nature powers
Simply put, they were either powerful forces rose from the ashes of old worlds or the ones formed by us and other species from different realms.

List of superstates
Below are 28 superpowers in 22nd century. In no particular order
 * 1) African Union
 * 2) Baltic Union
 * 3) Dutch Republic
 * 4) Confederation of Sovereignty Asian Republics
 * 5) Earth Empire
 * 6) East Asian Federation
 * 7) European Federal Union
 * 8) German Confederation
 * 9) Indochina Commonwealth
 * 10) Scandinavian Confederation
 * 11) Star Alliance
 * 12) Swiss Confederation (later become Greater Swiss Confederacy)
 * 13) Terran Coalition
 * 14) United Earth