Legally, who has the authority to send the US to war?

Here's an exchange in congressional testimony between Sen. Sessions and SecDef Panetta.  I learned in Government class, that only Congress has the authority to declare war.  I know that has gotten muddy with the advent of the military action by Executive Order, but I don't recall anywhere that we have to get permission from the rest of the world in order to do anything.  Am I surprised that apparently, this is the new "precedent" under this administration.  Not so much.  Here's the exchange:


Senator Jeff Sessions (R):
Do you think you can act without Congress and act, and initiate a no-fly zone in Syria? Without Congressional approval?


Secretary of Defense Leon Panetta:
Again, our goal would be to uh, to seek international permission and we, and we would come to the Congress and inform  you and determine how best to approach and whether or not we would want to get permission from the Congress, I think those are issues we would have to discuss as we decide what to do here.


Senator Jeff Sessions (R):
Well, I'm almost breathless about that.  Because what I heard you say is we're going to seek international approval and then you will come and tell the Congress what we might do.  And we might seek Congressional approval.  


Secretary of Defense Leon Panetta:
Well-


Senator Jeff Sessions (R):
Now, I want to say to you, that's a big dis-, wouldn't you agree? You've served in the congress...


Secretary of Defense Leon Panetta:
Yeah-


Senator Jeff Sessions (R):
Wouldn't you agree? That that's...uh...would be pretty breathtaking to the average americans?  So, would you like to clarify that?


Secretary of Defense Leon Panetta:
<Stutter and stammer> You know, I've also served with Republican presidents and Democratic presidents, who have always reserved the right to defend this country if necessary.


Senator Jeff Sessions (R):
But before you do this, you would seek permission from the international authorities...?


Secretary of Defense Leon Panetta:
If we're working with an international coalition, and we're working with NATO...we would want to be able to, be able to get appropriate permissions in order to be able to do that. That's something that all of these countries would want to have some legal basis on which to act. 


Senator Jeff Sessions (R):
What legal basis are you looking for?  What, what entity?


Secretary of Defense Leon Panetta:
Well, obviously the UN, if NATO made the decision to go in, that would be one...if we, if we developed an international coalition beyond NATO, then oviously some kind of UN security resolution.


Senator Jeff Sessions (R):
So you're saying that NATO would give you a legal basis? And an ad-hoc coalition of nations would provide a legal basis?


Secretary of Defense Leon Panetta:
If we were able to put together a coalition...and we're able to move together, then obviously we would seek whatever legal basis we would need in order to make that justified.  I mean, we can't just pull them all together, in a combat operation, without getting the legal basis in which to act.


Senator Jeff Sessions (R):
Who are you asking for the legal basis from?


Secretary of Defense Leon Panetta:
If it's um, if the UN passed a security resolution as it did in Libya, we would do that, if NATO came together as we did in Bosnia, we would rely on that. So we have options here, if we want to build the kind of international approach to dealing with the situation.


Senator Jeff Sessions (R):
Well, I'm all for having international support, but I'm really baffled by the idea that somehow an international assembly provides a legal basis for the United States military to be deployed in combat. I don't believe it's close to being correct.  They provide no legal authority. The only legal authority that's required to deploy the United States military is the Congress and the President and the law and the Constitution.


Secretary of Defense Leon Panetta:
Let me, just for the record, be clear again, Senator, so there's no misunderstanding. When it comes to the national defense of this country, the President of the United States has the authority under the Constitution, to act to defend this country.  And we will.  If it comes to an operation where we're trying to build a coalition of nations, to work together, to go in and operate as we did in Libya or Bosnia, for that matter Afghanistan, we want to do it with permissions either by NATO or the international community.



Original Video: via Sen. Sessions Youtube: