10 U.S.C. § 161 — Combatant commands: establishment

(a) Unified and Specified Combatant Commands. With advice and assistance from the Chairman of the Joint Chiefs of Staff, the President, acting through the Secretary of Defense, must establish unified combatant commands and specified combatant commands to perform military missions, and must prescribe the force structure of those commands. (b) Periodic Review. The Chairman must periodically — at least once every two years — review the missions, responsibilities (including geographic boundaries), and force structure of each combatant command, and recommend to the President, through the Secretary of Defense, any changes to those missions, responsibilities, and force structures that may be necessary. Except during a time of hostilities or imminent threat of hostilities, the President has reporting duties too. If the President establishes a new combatant command, the President must, within 60 days, notify Congress of its establishment and provide Congress a briefing on it. If the President significantly revises the missions, responsibilities, or force structure of an existing combatant command, the President must, within 60 days, notify Congress of the revisions and provide a briefing on them. (c) Definitions. A "unified combatant command" is a military command with broad, continuing missions, composed of forces from two or more military departments. A "specified combatant command" is a military command with broad, continuing missions, normally composed of forces from a single military department. "Combatant command" means either a unified combatant command or a specified combatant command.