10 U.S.C. § 12313

1. (a)Except as otherwise provided in this title, the Secretary concerned may at any time release a Reserve under his jurisdiction from active duty.
2. (b)In time of war or of national emergency declared by Congress or the President after January 1, 1953, a member of a reserve component may be released from active duty (other than for training) only if—This subsection does not apply to an armed force during a period of demobilization or reduction in strength of that armed force.
   1. (1)a board of officers convened at his request by an authority designated by the Secretary concerned recommends the release and the recommendation is approved;
   2. (2)the member does not request that a board be convened; or
   3. (3)his release is otherwise authorized by law.