I'm back, and with me I bring a rather convincing theory on the New Colonial Alliance.

They're ONI, and here's why I think that:

  • They knew about the Infinity, which was being built by ONI over the span of 20 years with total communications blackout in effect so that the word about it doesn't get out. The only ones outside of ONI that knew about it were the senior members of the Admiralty, most notably Lord Hood, who took it for the fleet instead of naval intelligence. Admiral Drake, the leader of the NCA, has nothing on his past revealed, and he could easily be affiliated with ONI.
  • Ilsa Zane was sent to lead a team to take over the Infinity by the time it was finished. Zane's official story was that the experimental SPARTAN-IV augmentations made her insane, and as a result she was discharged from the program and assigned to ONI before becoming an NCA member. As I said, that was the official story, because if she really was crazy, Zane would not have been selected to lead the group to capture the Infinity.
  • The fact that they wanted to take the Infinity for themselves, because as I said above, the Infinity's construction was originally an ONI project before the fleet branch took it. And since the Infinity was the most powerful ship humanity has ever built (since it literally took half of the UNSC's shipbuilding budget to build, along with all the Covenant and Forerunner tech found during the war), ONI would want that ship back to carry out their increasingly illegal actions. But since they can't have their own members wearing ONI uniforms as they perform their hijacking, they revealed (fabricated) intelligence on a new Insurrectionist group called the New Colonial Alliance that would carry out with performing the more illegal crap, the kind that would send the heads of ONI to the firing squads should Hood discover that what they're doing is practically treason, whenever ONI wishes.
  • An ONI prowler appeared to pick up Ilsa Zane after she was thrown out of the airlock during her failed attempt to capture the Infinity. The fact that not only did the prowler showed up to bring her inside the ship, but also knew exactly where she was after getting spaced, shows that Zane still has ONI connections.
  • Five years after their attempt to take the Infinity, the NCA shows up again on Ealen IV, this time hiring a mercenary army to assassinate the peace delegation ambassadors, Thel and Lydus, two powerful and extremely influential members of the Sangheili and Jiralhanae races. Their deaths would cease any attempts at peace talks between the two races and resume the fighting, which as shown in the first two Kilo-Five novels, is something that ONI is actively attempting to do in a (poorly thought out) attempt to ensure humanity's survival after the Human-Covenant War.
  • Vladimir Scruggs, the NCA mole, appears to know why Thel is unable to unite his people; seeing as how splintering the Sangheili people was an ONI black-ops assignment known only to Parangosky and the Kilo-Five squad, there is no way that Scruggs can know about this unless he was privy to such information, meaning he has to be ONI himself (in addition to Osman trusting him enough to give him such information). And Scruggs taking Lord Hood hostage? Who's to say that Osman, the head of ONI, hasn't secretly arranged the deaths of everyone in her way until she's placed herself as being next in command of the entirety of the UNSC should anything happen to Hood?
  • Daniel Clayton, an NCA officer, is sent to the Midnight Facility detention center after his capture, and it is a place run by ONI and notably the location Parangosky sentenced one of her ONI researchers, Dr. Magnusson, after her failure at keeping Jul 'Mdama contained. Why would an Insurrectionist and known terrorist be sent to the same prison as an ONI researcher that was sentenced there by her boss out of spite? It wouldn't make any sense unless this is a place ONI agents are sent to for failing their missions if they aren't killed outright.