22 C.F.R. § 227.500 – Secretary of Defense.

(a) The Secretary of Defense may exempt, on a case-by-case basis, a covered Federal action from the prohibition whenever the Secretary determines, in writing, that such an exemption is in the national interest. The Secretary shall transmit a copy of each such written exemption to Congress immediately after making such a determination.
(b) The Department of Defense may issue supplemental regulations to implement paragraph (a) of this section.