UNSC

The United Nations Space Command (UNSC) is humanity's primary defensive force in the universe. The UNSC fought against aliens in the Great War, which led to the creation of Project Freelancer (PFL). PFL's purpose was to find a suitable solution to the Great War for the UNSC, leading to secret law breakings and morally questionable methods.

Most of the members of Project Freelancer's simulations (such as Blood Gulch and its simulations with the Splinters) come from the UNSC, and are actually transported to their simulations by UNSC personnel.

When PFL's wrongdoings were revealed entirely, the UNSC shut them down and arrested anyone they could. However, the UNSC neglected the Freelancers themselves, leaving them with nowhere to go and no objective in sight. This led to several supersoldiers (equipped with incredibly advanced technology) to be scattered across the universe, some of them forming the Splinters and basically restarting PFL with help from the UNSC. This was a huge mistake on the UNSC's part.

After the destruction of the Splinters, the UNSC have yet to acknowledge the remaining simulation troopers in Blood Gulch, but they continue to send more and more soldiers there.