Opinions of the Office of Legal Counsel in Volume 42
4
literally running from the halls of Montezuma to the shores of Tripoli and
beyond.
1
Many of those actions were approved by opinions of this Office or
of the Attorney General, and many involved engagements considerably
broader than the April 2018 Syrian strikes. The Constitution reserves to
Congress the authority to “declare War” and thereby to decide whether to
commit the Nation to a sustained, full-scale conflict with another Nation.
Yet Presidents have repeatedly engaged in more limited hostilities to ad-
vance the Nation’s interests without first seeking congressional authoriza-
tion.
The President’s authority to direct U.S. military forces arises from Article
II of the Constitution, which makes the President the “Commander in Chief
of the Army and Navy of the United States,” U.S. Const. art. II, § 2, cl. 1,
and vests in him the Executive Power, id. art. II, § 1, cl. 1. These powers
allow him “to direct the movements of the naval and military forces placed
by law at his command.” Fleming v. Page, 50 U.S. (9 How.) 603, 615
(1850). Chief Justice Marshall suggested that the President’s “high duty” to
“‘take care that the laws be faithfully executed,’” as well as his power as
1
After receiving an ultimatum from the Bey of Tripoli in May 1801, President Jefferson
dispatched U.S. ships to the Mediterranean with orders, in the event the Barbary Powers
declared war, to “distribute your force . . . so as best to protect our commerce & chastise their
insolence—by sinking, burning or destroying their ships & Vessels wherever you shall find
them.” David P. Currie, The Constitution in Congress: The Jeffersonians, 1801–1829, at 127–
28 (2001). After Tripoli declared war, the United States launched a surprise attack on a
Tripolitan vessel. Id. at 128. In reporting the action to Congress, Jefferson elided the offen-
sive nature of the attack and sought authorization to “go beyond the line of defense,” id. at
124, 128, which Congress granted on February 6, 1802. See Act of Feb. 6, 1802, ch. IV, § 2,
2 Stat. 129, 130.
After Congress annexed Texas, President Polk deployed the U.S. military 150 miles
south of the disputed border with Mexico to the Rio Grande in June 1845. See David P.
Currie, The Constitution in Congress: Descent into the Maelstrom, 1829–1861, at 102
(2005); 4 A Compilation of the Messages and Papers of the Presidents, 1788–1897, at 437,
440 (James D. Richardson ed., 1897); see also Cambodian Sanctuaries, 1 Op. O.L.C. Supp.
at 327. After active hostilities commenced, Congress declared war. See Act of May 13,
1846, ch. XVI, 9 Stat. 9 (1846); see also The Prize Cases, 67 U.S. (2 Black) 635, 668
(1863) (“The battles of Palo Alto and Resaca de la Palma had been fought before the
passage of the Act of Congress of May 13th, 1846, which recognized ‘a state of war as
existing by the act of the Republic of Mexico.’ This act not only provided for the future
prosecution of the war, but was itself a vindication and ratification of the Act of the
President in accepting the challenge without a previous formal declaration of war by
Congress.”).