Since Sept. 11, 2001, the Army National Guard has called more than 400,000 soldiers to active duty to support operational requirements relating to the war on terrorism. These demands have furthered the Guard’s transformation from a traditional strategic reserve to an operational reserve. Such large-scale mobilizations have brought to light several significant concerns about the mobilization process, solutions for which are being actively sought and may be resolved by the Army over time and budget cycles.

http://www.armedforcesjournal.com/2008/09/3651732