Secretary of Defense Donald H. Rumsfeld briefs reporters about the changes he has endorsed to the Unified Command Plan during a press briefing at the Pentagon on April 17, 2002. The Chairman of the Joint Chiefs of Staff Gen. Richard B. Myers, U.S. Air Force, recommended the changes in a report to President George W. Bush. The plan creates the U.S. Northern Command which will assume the mission of defending the United States and supporting the full range of military assistance to civil authorities. The Unified Command Plan is the document that establishes the missions and responsibilities, as well as the geographic boundaries, of each combatant command.