Article I, Section 8, Clause 11:
[The Congress shall have Power . . .] To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water; . . .
In the early draft of the Constitution presented to the Convention by its Committee of Detail, Congress was empowered
to make war. 1 Although there were solitary suggestions that the power should better be vested in the President alone, 2 in the Senate alone, 3 or in the President and the Senate, 4 the sentiment of the Convention, as best we can determine from the limited notes of the proceedings, was that the potentially momentous consequences of initiating armed hostilities should be called up only by the concurrence of the President and both Houses of Congress. 5 In contrast to the English system, the Framers did not want the wealth and blood of the Nation committed by the decision of a single individual; 6 in contrast to the Articles of Confederation, they did not wish to forego entirely the advantages of executive efficiency nor to entrust the matter solely to a branch so close to popular passions. 7
The result of these conflicting considerations was that the Convention amended the clause so as to give Congress the power to
declare war. 8 Although this change could be read to give Congress the mere formal function of recognizing a state of hostilities, in the context of the Convention proceedings it appears more likely the change was intended to insure that the President was empowered to repel sudden attacks 9 without awaiting congressional action and to make clear that the conduct of war was vested exclusively in the President. 10
An early controversy revolved about the issue of the President's powers and the necessity of congressional action when hostilities are initiated against us rather than the Nation instituting armed conflict. The Bey of Tripoli, in the course of attempting to extort payment for not molesting United States shipping, declared war upon the United States, and a debate began whether Congress had to enact a formal declaration of war to create a legal status of war. President Jefferson sent a squadron of frigates to the Mediterranean to protect our ships but limited its mission to defense in the narrowest sense of the term. Attacked by a Tripolitan cruiser, one of the frigates subdued it, disarmed it, and, pursuant to instructions, released it. Jefferson in a message to Congress announced his actions as in compliance with constitutional limitations on his authority in the absence of a declaration of war. 11 Hamilton espoused a different interpretation, contending that the Constitution vested in Congress the power to initiate war but that when another nation made war upon the United States we were already in a state of war and no declaration by Congress was needed. 12 Congress thereafter enacted a statute authorizing the President to instruct the commanders of armed vessels of the United States to seize all vessels and goods of the Bey of Tripoli
and also to cause to be done all such other acts of precaution or hostility as the state of war will justify . . . . 13 But no formal declaration of war was passed, Congress apparently accepting Hamilton's view. 14
Sixty years later, the Supreme Court sustained the blockade of the Southern ports instituted by Lincoln in April 1861 at a time when Congress was not in session. 15 Congress had subsequently ratified Lincoln's action, 16 so that it was unnecessary for the Court to consider the constitutional basis of the President's action in the absence of congressional authorization, but the Court nonetheless approved, five-to-four, the blockade order as an exercise of Presidential power alone, on the ground that a state of war was a fact.
The President was bound to meet it in the shape it presented itself, without waiting for Congress to baptize it with a name; and no name given to it by him or them could change the fact. 17 The minority challenged this doctrine on the ground that while the President could unquestionably adopt such measures as the laws permitted for the enforcement of order against insurgency, Congress alone could stamp an insurrection with the character of war and thereby authorize the legal consequences ensuing from a state of war. 18
The view of the majority was proclaimed by a unanimous Court a few years later when it became necessary to ascertain the exact dates on which the war began and ended. The Court, the Chief Justice said, must
refer to some public act of the political departments of the government to fix the dates; and, for obvious reasons, those of the executive department, which may be, and, in fact, was, at the commencement of hostilities, obliged to act during the recess of Congress, must be taken. The proclamation of intended blockade by the President may therefore be assumed as marking the first of these dates, and the proclamation that the war had closed, as marking the second. 19
These cases settled the issue whether a state of war could exist without formal declaration by Congress. When hostile action is taken against the Nation, or against its citizens or commerce, the appropriate response by order of the President may be resort to force. But the issue so much a source of controversy in the era of the Cold War and so divisive politically in the context of United States involvement in the Vietnam War has been whether the President is empowered to commit troops abroad to further national interests in the absence of a declaration of war or specific congressional authorization short of such a declaration. 20 The Supreme Court studiously refused to consider the issue in any of the forms in which it was presented, 21 and the lower courts generally refused, on
political question grounds, to adjudicate the matter. 22 In the absence of judicial elucidation, the Congress and the President have been required to accommodate themselves in the controversy to accept from each other less than each has been willing to accept but more than either has been willing to grant. 23