(a) In General.—Under such regulations as the Secretary of Defense may prescribe, a sentence of confinement adjudged by a military commission under this chapter may be carried into execution by confinement—
(b) Treatment During Confinement by Other Than the Armed Forces.—
Persons confined under subsection (a)(2) in a penal or correctional institution not under the control of an armed force are subject to the same discipline and treatment as persons confined or committed by the courts of the United States or of the State, District of Columbia, or place in which the institution is situated.