Reading the Constitution, though...Congress's power to declare war appears in the midst of the main list of its other legislative powers, in the eleventh of eighteen clauses in Article I, section 8 of the Constitution. It is not distinguished by any mark that would set it apart from the other powers in the list, each of which calls for the same legislative process described in Article I, section 7: "Every Bill . . . shall, before it become a Law, be presented to the President of the United States" for his signature or veto; and "Every Order, Resolution, or Vote to which the concurrence of the Senate and the House of Representatives may be necessary (except on a question of Adjournment) shall be presented to the President" likewise."Congress shall have the power to declare war" means that Congress has the power.
So...Are declarations of war "laws passed by Congress? Inasmuch as they activate an authority on the President"s part that will in many instances be dormant otherwise, how could they not be?
As evidence pointing in this direction at least, what about the December 11, 1941 declaration of war against Germany. It is "Public Law 77-331." Nothing in our national legislative process becomes a "Public Law" without the signature of the president, his inaction during the period assigned for his decision to sign or veto, or an overriding of his veto-all under the terms of Article I, section 7.
h/t to Matthew Frank at NRO.
So what's this mean? Is the power to declare war a plenary authority belonging to Congress or is it a shared authority? It appears to be a shared authority wherein Congress is simply declaring that a state of war exists between the US and another nation and means nothing more than committing the nation to such a state of war. In other words, the power to declare war constitutes only a formal documentation of executive war-making decisions.
Of course.It does not mean that the ONLY way the Unites States can find itself in a state of war is through such a declaration, and it certainly does not mean that the only crcumstance under which the CinC may use military force is pursuant to said declaration.