Maybe Chief sides with Halsey, and protects her from something. (Most likely the UNSC); and the UNSC have sent this new Spartan character to try to capture them?
Opinions?
Chief has very little reason to turn his back on the UNSC. What have they done to him? Nothing.
Could Halsey manipulate him into thinking that the UNSC wanted her dead? Perhaps. But I think Halsey is smart enough to know that ONI wanted her dead. After all, Lasky was trying to defend her along with Majestic.
I honestly think that Halsey will be going after ONI more than the UNSC.
Plus, Regardless of Halsey position; I don’t think John will look too kindly on her siding with the enemy he’s been fighting for the past 30 years.