He does not initiate the war, but is bound to accept the challenge without waiting for any special legislative authority. Speaking for the majority of the Court, Justice Grier answered: “If a war be made by invasion of a foreign nation, the President is not only authorized but bound to resist force by force. 140 The argument was advanced that a blockade to be valid must be an incident of a “public war” validly declared, and that only Congress could, by virtue of its power “to declare war,” constitutionally impart to a military situation this character and scope. The immediate issue was the validity of the blockade that the President, following the attack on Fort Sumter, had proclaimed of the Southern ports.

137 In his famous message to Congress of July 4, 1861, 138 Lincoln advanced the claim that the “war power” was his for the purpose of suppressing rebellion, and in the Prize Cases 139 of 1863 a divided Court sustained this theory.

The Prize Cases.-The basis for a broader conception was laid in certain early acts of Congress authorizing the President to employ military force in the execution of the laws. “But in the distribution of political power between the great departments of government, there is such a wide difference between the power conferred on the President of the United States, and the authority and sovereignty which belong to the English crown, that it would be altogether unsafe to reason from any supposed resemblance between them, either as regards conquest in war, or any other subject where the rights and powers of the executive arm of the government are brought into question.” 135 Even after the Civil War, a powerful minority of the Court described the role of President as Commander-in-Chief simply as “the command of the forces and the conduct of campaigns.” 136 But his conquests do not enlarge the boundaries of this Union, nor extend the operation of our institutions and laws beyond the limits before assigned to them by the legislative power.” He may invade the hostile country, and subject it to the sovereignty and authority of the United States. As commander-in-chief, he is authorized to direct the movements of the naval and military forces placed by law at his command, and to employ them in the manner he may deem most effectual to harass and conquer and subdue the enemy. The answer then given was, that though the president might, there was no necessity that he should, take the command in person and there was no probability that he would do so, except in extraordinary emergencies, and when he was possessed of superior military talents.” 134 In 1850, Chief Justice Taney, for the Court, wrote: “His duty and his power are purely military. The consent of both houses of Congress ought, therefore, to be required, before he should take the actual command. But it was urged, that it would be dangerous to let him command in person, without any restraint, as he might make a bad use of it. Hamilton said the office “would amount to nothing more than the supreme command and direction of the Military and naval forces, as first general and admiral of the confederacy.” 133 Story wrote in his Commentaries: “The propriety of admitting the president to be commander in chief, so far as to give orders, and have a general superintendency, was admitted. The Limited View.-The purely military aspects of the Commander-in-Chiefship were those that were originally stressed. 132 But the principal concern here is the nature of the power granted by the clause. From the evidence available, it appears that the Framers vested the duty in the President because experience in the Continental Congress had disclosed the inexpediency of vesting command in a group and because the lesson of English history was that danger lurked in vesting command in a person separate from the responsible political leaders. Surprisingly little discussion of the Commander-in-Chief Clause is found in the Convention or in the ratifying debates. The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Office, and he shall have Power to grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachment.

Commander in chief of the military