UNSC

The United Nations Space Command or UNSC, is the military, exploratory, and scientific agency of the Unified Earth Government commissioned in 2163. The Unified Earth Government, or UEG, is the central civilian government that administers Earth and its colonies throughout a portion of the Orion Arm of the Milky Way galaxy.

The UNSC is human and the conflict in Halo is with the The Covenant Empire, a theocratic hegemony made up of multiple alien species that maintained control over a large portion of the Orion Arm in the Milky Way galaxy.