The President, after all, is the “Commander in Chief of the Army and Navy of the United States.” U.S.Const., Art. II, § 2. His authority to classify and control access to information bearing on national security and to determine whether an individual is sufficiently trustworthy to occupy a position in the Executive Branch that will give that person access to such information flows primarily from this constitutional investment of power in the President, and exists quite apart from any explicit congressional grant. See Cafeteria Workers v. McElroy, 367 U. S. 886, 367 U. S. 890 (1961). This Court has recognized the Government’s “compelling interest” in withholding national security information from unauthorized persons in the course of executive business. Snepp v. United States, 444 U. S. 507, 444 U. S. 509, n. 3 (1980). See also United States v. Robel, 389 U. S. 258, 389 U. S. 267 (1967); United States v. Reynolds, 345 U. S. 1, 345 U. S. 10 (1953); Totten v. United States, 92 U. S. 105, 92 U. S. 106 (1876). The authority to protect such information falls on the President as head of the Executive Branch and as Commander in Chief.