On the Constitution and War

Notes toward A Guide for the Perplexed

I am going to explore, in a few paragraphs, some of the central constitutional issues associated with the President’s authority to use military force. I am going to bracket issues under the War Powers Resolution. I am not going to discuss questions about what kind of congressional consultation, or authorization, is prudent. Also, I am not going to discuss current events in these remarks, though what I have to say will obviously be relevant to them.

This is not exactly a guide for the perplexed, because it is too brief and brisk for that. But it might be seen as notes toward such a guide.

1.

Here’s a (pretty amazing), discussion from the Constitutional Convention:

"To make war"

Mr Pinkney opposed the vesting this power in the Legislature. Its proceedings were too slow. It wd. meet but once a year. The Hs. of Reps. would be too numerous for such deliberations. The Senate would be the best depositary, being more acquainted with foreign affairs, and most capable of proper resolutions. If the States are equally represented in Senate, so as to give no advantage to large States, the power will notwithstanding be safe, as the small have their all at stake in such cases as well as the large States. It would be singular for one authority to make war, and another peace.

Mr Butler. The Objections agst the Legislature lie in a great degree agst the Senate. He was for vesting the power in the President, who will have all the requisite qualities, and will not make war but when the Nation will support it.

Mr. Madison and Mr Gerry moved to insert "declare," striking out "make" war; leaving to the Executive the power to repel sudden attacks.

Mr Sharman thought it stood very well. The Executive shd. be able to repel and not to commence war. "Make" better than "declare" the latter narrowing the power too much.

Mr Gerry never expected to hear in a republic a motion to empower the Executive alone to declare war.

Mr. Elseworth. there is a material difference between the cases of making war, and making peace. It shd. be more easy to get out of war, than into it. War also is a simple and overt declaration. peace attended with intricate & secret negociations.

Mr. Mason was agst giving the power of war to the Executive, because not safely to be trusted with it; or to the Senate, because not so constructed as to be entitled to it. He was for clogging rather than facilitating war; but for facilitating peace. He preferred "declare" to "make".

On the Motion to insert declare--in place of Make, it was agreed to.

2.

Okay then. We seem to have here the following positions:

(1) The executive gets to make war on its own;

(2) no war can be made without one or both houses of Congress authorizing it (perhaps the Senate alone, perhaps Congress as such);

(3) no war can be made without Congress authorizing it, consistent with (2); but the executive can repel sudden attacks.

At first glance, the Constitution, understood in terms of the foregoing exchange, seems to embody (3). (Note that it might be questioned whether it should be understood in light of that exchange.) “Declare,” instead of “make,” authorizes unilateral presidential action to repel (sudden) attacks, on the theory that the nation needs to be able to respond quickly. But if there is no risk of (sudden) attacks, the executive cannot make war on its own. A declaration of war appears to be a predicate for making war, absent a risk of (sudden) attacks.

But that conclusion is not irresistible. Maybe a declaration of war is a formal act that has a series of formal effects, with legal and international repercussions. Maybe such a declaration is not a prerequisite for presidential warmaking. The italicized passage seems best read to suggest that it is, and all things considered, there is a strong argument in favor of that conclusion. (I tend to think it is right, though I cannot defend that view here.) Still, it is disputed.

(Note: An authorization to use military force, it is generally agreed, has the same effect as a declaration of war.)

3.

What is a sudden attack? What has to be repelled? How likely must it be? How sudden must it be? And what must the attack, well, attack?

Let’s begin with the what. If the attack is on the territory of the United States, the issue is simple; of course the President may protect U.S. territory. Note that this conclusion should reach U.S. property outside of what is formally known as “the United States.” The theory is that the President can repel sudden attacks, and if U.S. property is at risk of sudden attack, the theory seems to be triggered, even if we are not speaking of Vermont or California.

The logic of the italicized discussion also suggests that the President may act to protect U.S. personnel outside of U.S. territory. If the President cannot do that, then U.S. personnel will be at serious risk. And indeed, this has been the conventional understanding. So the “what” is pretty broad.

What does “sudden attack” mean? If an attack is imminent, surely the President may act. So too, it makes sense to say, if it is “soon.” We can imagine cases that test the meaning and boundaries of “soon,” but the underlying logic is not obscure (“Its proceedings were too slow. It wd. meet but once a year. The Hs. of Reps. would be too numerous for such deliberations.”).

But if there is plenty of time to get congressional authorization, the President must get congressional authorization. Of course there is a good argument that the President’s judgments (on, say, the plenty of time question), though likely to be self-serving, are entitled to a measure of respect and deference. After all, he is Commander-in-Chief.

4.

And what is “war”? You might want to insist that there is a difference between (1) military actions, using force and (2) “war.”

Actually it is clear that there has to be such a distinction. If the United States uses military force in a ten-minute skirmish in a dangerous area, it need not be involved in “war.” And longstanding practice suggests that there is such a distinction. As Curtis Bradley and Jack Goldsmith put it in 2004, “Indeed, most uses of military force in U.S. history, including significant military engagements such as the Korean War and the Kosovo bombing campaign, have been initiated without express congressional authorization.” (See https://chicagounbound.uchicago.edu/cgi/viewcontent.cgi?article=14123&context=journal_articles)

Maybe some of these practices violated the Constitution. But Attorney General Robert Jackson said this a long time ago: “the President’s authority has long been recognized as extending to the dispatch of armed forces outside of the United States, either on missions of goodwill or rescue, or for the purpose of protecting American lives or property or American interests.” Training of British Flying Students in the United States, 40 Op. Att’y Gen. 58, 62 (1941).

Jackson’s statement can be taken to fall within the domain of defensive action, in the general vicinity of repelling sudden attacks. But the Office of Legal Counsel has been quite emphatic in emphasizing that offensive actions may fall short of war. (See https://www.justice.gov/olc/file/2011-04-01-libya-deployment/dl?inline) In its words: “the historical practice of presidential military action without congressional approval precludes any suggestion that Congress’s authority to declare war covers every military engagement, however limited, that the President initiates.”

Let us simply stipulate that limited military engagements, by the President acting alone, are permissible, even if, or even though, wars are not. What is the line between the two?

OLC says, not unreasonably, that we need to make “a fact-specific assessment of the ‘anticipated nature, scope, and duration’ of the planned military operations.” A war would include “prolonged and substantial military engagements, typically involving exposure of U.S. military personnel to significant risk over a substantial period.”

By contrast, “a planned deployment of up to 20,000 United States troops to Haiti to oust military leaders and reinstall Haiti’s legitimate government” would not amount to a war “requiring advance congressional approval.” The same conclusion would hold for “a proposed deployment of approximately 20,000 ground troops to enforce a peace agreement in Bosnia and Herzegovina.” That may or may not be right, but it’s helpful. (For one view of some of the complexities here, contesting OLC’s view, see https://originalismblog.typepad.com/the-originalism-blog/2025/06/the-constitution-and-iran-michael-ramsey.html)

In any case, it makes sense to say that we do need to look at nature, scope, and duration. A limited military operation (extending for a day or two, or three, or more), need not be a war, certainly if it is also limited in scope. (But a full-on attack on a foreign nation could be a war, even if it lasts just a day or even an hour, because of its scope.)

OLC works for the President, of course, and it would be fair to say that in opining on the President’s authorities, it is not exactly neutral. But history has long vindicated the view that some military operations, not involving “prolonged and substantial military engagements,” do not amount to war.

That does not answer every question, but it answers a lot of them. Plenty of actions fall on one or another side of the line.