Board Thread:Questions and Answers/@comment-64.222.202.2-20140419011507

I am probably just missing something obvious, but I am watching the entire series for the second time, and I still can't figure out who Project Freelancer was at war with. In the missions they make around seasons nine and ten, where the freelancers are attacking different bases and targets, what organization do they all belong to?

The enemies all seem to have UNSC gear. Are they a rival faction of the UNSC or something--and if so, why hasn't the UNSC itself stopped the infighting? 