Overlord

Overlord is the American command base who gives orders to the US Army Rangers, particularly Hunter Two-One, in Call of Duty: Modern Warfare 2. He is heard in "Team Player", "Of Their Own Accord","Wolverines!" and many other levels. Overlord was also the U.S. Command from Call of Duty 4: Modern Warfare during the U.S. Marine invasion of Al-Asad's country (labeled "Command" in the subtitles). He appears to command, or broadcast orders to troops in a large theatre of operations. During combat, he gives information on enemy strength and location, as well as new orders or objectives to soldiers in action. Overlord is not directly affiliated with Shepherd and his Shadow Company aside from both being U.S./NATO military personel, as Shepherd can be heard contacting Oxide, Overlord's Shadow Company equivalent.

Trivia

 * Overlord is voiced by Glenn Morshower, most famous for his role as Aaron Pierce in the TV Show 24 and numerous roles as a high-ranking military officer. He also plays multiple roles in the Transformers movies. He also plays a similar role in Black Hawk Down as the Mobile Tactical Operations Command in a Blackhawk on overwatch.
 * His role is the same as Shadow Company's Oxide and the SAS's Baseplate.
 * An interesting line can be heard if the player scores 3, 10 kill predator missile shots in quick succession during singleplayer. This is easiest to do during the scene where the player takes control of the AGM missile console from the enemy hiding in a food store. The enemies in this mission spawn very clustered at first. After doing this overlord will message you with something similiar to "Oh man. Another 10 confirmed, Good hit 2-1 good hit".
 * Overlord is fairly old compared to the other U.S. personel, and speaks with a southern accent.
 * Overlord is heard in the Call of Duty: Modern Warfare 2 AC-130 trailer announcing the status of the AC-130. Presumably he was going to be the Multiplayer announcer for the Rangers.