High Command (HIGHCOM) is the top operational command of the ONI CC. It is in charge of all personnel, equipment, requisitions, facilities, and installations under military control. The two main offices utilized by HIGH are the Unified Ground Command (UNICOM) and Naval Command (NAVCOM). HIGHCOM has been the single source of direction in terms of military strategy, from dealing with local insurrections, to the genocidal war with The Covenant. HIGHCOM is one of the most vital branches in the ONI CC.
High Command served the same role in both The UNSC and The ONI CC.