Overwatch

The Combine Overwatch, also known simply as Overwatch, is the general self-titled name of the Combine's military and law enforcement on Earth. Overwatch is the suffix designation of the military forces in the various sectors. Various sectors include Sector 17 Overwatch for City 17, Quarantine Zone, Nova Prospekt, the wasteland, and other parts of the world.

Overwatch also explicitly refers to the Combine's automated Command System on Earth encountered as the Overwatch Voice. Although primarily made for garrisoning Earth, there is a suggestion that Overwatch soldiers are throughout Combine controlled worlds on various off-world assignments in other territories.

Overview
The Combine Overwatch primarily consists mainly of a wide variety of unit types, such as the Combine Soldiers, supported by many Synth forces as support. Overwatch forces divide into distinct "sectors" designated to them depending on their general location, such as Sector 17 Overwatch focus around an urban center forces other than Sector 17 Overwatchare not directly encountered in the games.

Artificial intelligence that acts as command known as The Overwatch voice oversees Day-to-day military activities and operations. The Overwatch Voice issues orders, instructions, and relaying information to the Overwatch forces to assist and fulfill objectives. Overwatch has a command structure from squad leaders leading whole squads to an entire Sector led by a sector leader.

As seen at Nova Prospekt, a high-ranking Combine officer inquires the status of several groups along the coast on the radio and field promotes one of them to command the rest when the previous one fell to Gordon Freeman's hands. During the events of Half-Life: Alyx, Overwatch Command were inquiring damage assessments from a Combine grunt stationed on the ground beneath The Vault before needing to send reinforcements into the Quarantine Zone.

The Citadel, located in City 17, acts as the main base of operations for the Combine Overwatch on Earth, with multiple sites, garrisons, and other strongholds throughout the many cities and other territories. The Combine forces on Earth are under the administration of Dr. Wallace Breen, who serves as Earth's Administrator, with the Advisors, a race of aliens responsible for overseeing all activities and communications between Earth and the rest of the Combine.