715. The Prosecution Of War
The constitutional power given to the United States to declare and wage war, whether foreign or civil, carries with it the authority to use all means calculated to weaken the enemy and to bring the struggle to a successful conclusion. When dealing with the enemy all acts that are calculated to advance this end are legal. Indeed, the President in the exercise simply of his authority as commander-in-chief of the army and navy, may, unless prohibited by congressional statute, commit or authorize acts not warranted by commonly received principles of international law; and Congress may by law authorize measures which the courts must recognize as valid even though they provide penalties not supported by the general usage of nations in the conduct of war. Thus during the Civil War in certain cases the provision by congressional statute for the confiscation of certain enemy property or land was enforced, though such confiscation was not in accordance with the general usage of foreign States.
Even in dealing with its own loyal subjects, the power to wage war enables the government to override in many particulars private rights which in time of peace are inviolable.25
The power to wage war carries with it the authority not only to bring it to a full conclusion, but, after the cessation of active military operations, to take measures to provide against its renewal. As the court says in Stewart v. Kahn:26 "The measures to be taken in carrying on war and to suppress insurrection, are not defined. The decision of all such questions rests wholly in the discretion of those to whom the substantial powers involved are confided by the Constitution. In the latter case the power is not limited to victories in the field and to the dispersion of the insurgent forces. It carries with it inherently the power to guard against the immediate renewal of the conflict, and to remedy the evils which have arisen from its rise and progress."
24 Upon this point see the very thoughtful paper of T. S. Woolsey entitled "The Beginnings of War," published in Vol. I, p. 54, of the Proceedings of the American Political Science Association.
25 For the limitations upon the war powers in this respect, see post. 2611 Wall. 493; 20 L. ed. 176.
(From: The Constitutional Law Of The United States by Westel Woodbury Willoughby)