2013 Obama feels otherwise.

December 20, 2007:

Q. In what circumstances, if any, would the president have constitutional authority to bomb Iran without seeking a use-of-force authorization from Congress? (Specifically, what about the strategic bombing of suspected nuclear sites — a situation that does not involve stopping an IMMINENT threat?)

OBAMA:  The President does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation.

As Commander-in-Chief, the President does have a duty to protect and defend the United States. In instances of self-defense, the President would be within his constitutional authority to act before advising Congress or seeking its consent.