These units are activated under temporary orders by the owning Major Command (MAJCOM) for a specific purpose or mission.
Air Expeditionary Force I arrived fully armed and began to fly sorties within 12 hours of its initial landings.
This made establishment of permanent units more difficult, because base access might be changed or denied with shifting, volatile, political currents.
This created a lot of concern with Jordanian military personnel stationed at Shahid Muafaq Al-Salti Air Base during the initial stages.
As they were being told on television and radio that there were no U.S. troops on Jordanian soil, USAF C-17 aircraft were arriving on a daily basis with personnel and supplies.
To minimize the risk of these kind of situations happening, the decision was taken to avoid the creation of permanent units, especially in the Middle East.