50 U.S.C. § 831
Subject to the provisions of this subchapter, the Secretary of Defense (hereafter in this subchapter referred to as the “Secretary”) shall prescribe such regulations relating to continuing security procedures as he considers necessary to assure—
unless such employment, detail, assignment, or access to classified information is clearly consistent with the national security.
(Sept. 23, 1950, ch. 1024, title III, § 301, as added Pub. L. 88–290, , 78 Stat. 168.)