The lawfulness of action in Syria doesn't depend on magic words -- lawmakers can consent in any form they choose.

By Garrett Epps, The Atlantic, Sept. 3, 2013

[....] Contemporary Americans almost never read the Constitution. Instead, we seize on individual magic-sounding words ("declare war," "natural born," "keep and bear," etc.). I've spent the last three years studying the text, and it seems to me that, even in a crisis, we might want to read the words with the care we'd bring to, say, the instructions for assembling an Ikea wardrobe.

"Declare war," as regular readers know, was inserted into the document fairly late in the Philadelphia Convention. According to Madison's Notes, the Committee of Detail's draft gave Congress the entire power to "make war." Madison records that he offered the change to make clear that a president could respond to a "sudden attack." He records four delegates as supporting "declare war" while opposing any power by the president to commence a war; two delegates as opposing "declare war" because they wanted Congress to have all of the war power; and one as urging that the power to "declare war" be given to the president. (The Convention had a total of 55 delegates, though not all were present every day.) The "declare" language was adopted by a vote of seven states to two. 

It's a pretty slender "legislative history" from which to derive an "original intent." The Notes, for one thing, are not an official record, and were kept by a participant with his own axe to grind [....]