The purpose of each reserve component is to provide trained units and qualified persons available for active duty in the armed forces, in time of war or national emergency, and at such other times as the national security may require, to fill the needs of the armed forces whenever more units and persons are needed than are in the regular components.
10 U.S. Code § 10102. Purpose of reserve components
2004—Pub. L. 108–375 struck out “, during and after the period needed to procure and train additional units and qualified persons to achieve the planned mobilization,” after “whenever”.