Cue the prepared remarks:
Obviously, when we are at war, that's a decision the Department of Defense does not make. The commander-in-chief, the president of the United States makes that decision as to entering this country into a conflict. Now, we haven't declared war, which is the responsibility of the Congress for a long time, I think since '41, 1941, at the beginning of World War II.
Um. No. The president does have the authority to enter this country into a conflict if he needs to react to events too quickly to consult Congress. But Congress still has the authority to declare war.
There is admittedly a grey area. As commander-in-chief of the military, the president can initiate military action.
But to continue fighting, the president requires at least Congressional passive acceptance to continue to fund that military action over the long term. The War Powers Act is Congress's attempt to defend their war powers.
So the president is wise to consult Congress before ordering military action or shortly thereafter even if the president doesn't seek official and explicit Congressional approval. If the conflict is short and low cost, Congress is unlikely to complain. But if the conflict goes badly, Congress--controlled by either party--will not forget they weren't in at the beginning.
Let's be clear. Just because we have not had a declaration of war since 1941 does not mean that the power to declare war has become a presidential power. The Congressional Research Service makes this clear:
In contrast to an authorization [to use military force], a declaration of war in itself creates a state of war under international law and legitimates the killing of enemy combatants, the seizure of enemy property, and the apprehension of enemy aliens. While a formal declaration was once deemed a necessary legal prerequisite to war and was thought to terminate diplomatic and commercial relations and most treaties between the combatants, declarations have fallen into disuse since World War II. The laws of war, such as the Hague and Geneva Conventions, apply to circumstances of armed conflict whether or not a formal declaration or authorization was issued.
With respect to domestic law, a declaration of war automatically triggers many standby statutory authorities conferring special powers on the President with respect to the military, foreign trade, transportation, communications, manufacturing, alien enemies, etc. In contrast, no standby authorities appear to be triggered automatically by an authorization for the use of force, although the executive branch has argued, with varying success, that the authorization to use force in response to the terrorist attacks of 2001 provided a statutory exception to certain statutory prohibitions.
Remember, under the threat of nuclear war that could cripple the ability of Congress to pass the laws they passed to wage World War II, this was and probably still is a wise move for Congress to have made. Quickly declare war and the commander-in-chief has all the powers he needs to wage the war that our very survival may require us to win.
So a "declaration of war" complete with perhaps a foreign ambassador being called in to the Secretary of State's office to be formally slapped across both cheeks with a pair of white gloves sets in motion a lot of laws designed to cope with a global war on the scale of World War II when the president needs to mobilize our economy for war.
Start at page 49 of that CRS report for a stunning list of the breadth of powers transferred to the president in case of a declaration of war.
We don't face that situation because waging even wars like Iraq or Afghanistan (or both at once) require such a relatively small proportion of our GDP to fund.
So no, we don't have declarations of war like we once did. An authorization to use military force is Congress's answer to the problem of not wanting (or needing) to grant sweeping powers to the president while still maintaining the Constitutional power of Congress to provide the legal basis for conflict.
And I'd hope that our Secretary of Defense--who was once a United States Senator--would have even the beginning of a clue about this issue. But who is really surprised that Hagel does not have a grasp of that basic fact as he pretends to inform an audience about the powers of his department?
UPDATE: The link to the CRS report died but years later I found another copy here. [Note that the title is "Declarations of War and Authorizations for the Use of Military Force: Historical Background and Legal Implications" (March 2007) so you can search for it, since the direct link doesn't seem to work ...]
