As a result of the Global War on Terrorism, on 1 October 2003, AMC underwent a major restructuring, bringing a war fighting role to its numbered air force. AMC reactivated Eighteenth Air Force (18 AF) and established it as its main war fighting force. As subordinate components of 18 AF, AMC redesignated its two former numbered air forces as Expeditionary Mobility Task Forces (EMTF). Fifteenth Air Force was redesignated as the 15th Expeditionary Mobility Task Force (15 EMTF), headquartered at Travis AFB, and Twenty-First Air Force was redesignated as the 21st Expeditionary Mobility Task Force (21 EMTF), headquartered at McGuire AFB.