United Nations Space Command

"What the hell is the UNSC?"

- Grif

"Dunno, never heard of it. Sounds made up."

- Sarge in Reconstruction: Chapter 19

The United Nations Space Command, known as the UNSC for short, is humanity's primary defensive force. Unlike the Halo franchise, many of those within the UNSC are portrayed as being incompetent and serve only as a supporting role in the series.

Issues with Freelancers
During the Great War, the organization authorized Project Freelancer in hopes of creating a feasible solution to the Great War, but this unfortunately ended in failure. Though the project was not entirely dissolved, continuing to operate until its more illegal actions were publicly exposed. The organization then took what remained of Project Freelancer and shut it down.

At some point in the UNSC Maximum Security Detention Facility, the Chairman instructed Washington and the Meta to obtain the Epsilon A.I. for them in exchange for their freedom. However, the Meta betrayed Wash and was later killed by the Reds and Blues, while Washington avoided life imprisonment with the teams' aid before a group of UNSC soldiers arrived to the area.

Dealing with the Reds and Blues
Afterwards, during Season 10, Carolina has the Reds and Blues help her break into the UNSC Archives to rescue Epsilon from his memory unit, in order to use the A.I. to locate and kill the Director. This made the organization label the Reds and Blues as wanted criminals. In Reckless, members of the UNSC Police piloting Hornets attempt to arrest the Reds and Blues, but they instead have their vehicles hijacked by the simulation troopers.

However, the UNSC later pardoned the Reds and Blues because of their aid in bringing Project Freelancer to justice, which they were honored for before the UNSC attempted to take the soldiers home. Unfortunately, by Season 11, the UNSC ship that was to bring the Reds and Blues home crashed with the Reds and Blues being the only survivors.

Trivia

 * It's mentioned that the UNSC had authorized several other top-secret projects during the Great War, but they have yet to be shown. This could also be a reference to the SPARTAN-II Program in the Halo series.
 * The UNSC is responsible for the creation of the Federal Army of Chorus, New Republic, and Project Freelancer. During the Great War, the UNSC created Project Freelancer to originally be a splinter group, while also deserting the planet Chorus, which led to the formation of the Federal Army and New Republic to fight for control of the planet.
 * After Project Freelancer was shut down, all remaining equipment of the faction and the simulation troopers were given to the UNSC and the Chairman. However, it's revealed that groups of individuals have stolen some of this equipment and it became accessible throughout the galaxy.
 * The link between the UNSC featured in the Halo video game series and the one featured in the Red vs. Blue universe is dubious at best. In the first few episodes of the series, it was established that Spartan-117 Master Chief was a part of the story, and had defeated the Covenant Armada (the story of Halo: Combat Evolved). As the series progressed however, the story moved further away from Halo's own, using generalities such as "the army" and "the aliens" rather than the UNSC and the Covenant. Starting with Reconstruction however, the story has re-integrated many of Halo's story elements into the ongoing story, although loosely.
 * According to Reconstruction, it appears Grif doesn't know what the UNSC is, but ironically, he knows who Master Chief, who is from the UNSC.