Excerpts of the President's News Conference
I have given some thought to the suggestion for the outlawry of war. Any treaties made on that subject are somewhat difficult under our Constitution. Those difficulties were quite clearly set out some months ago by Dr. David Jayne Hill in an article that was, I think, in the Saturday Evening Post. I don't know that they are insuperable, but they are certainly very great, because our Constitution places the authority for a declaration of war in the Congress. Of course, that makes it quite obvious that any treaty that might be made would not take away from Congress the power to declare war. Such a treaty, however, would amount to a declaration of a policy that might be helpful in promoting a sentiment for peace. I don't know that we regard our own country any differently than other people regard theirs. I suppose that most of our people would say that this is a peaceful country as indicated by the very infrequent occasions in which it has resorted to war, emphasized by the many treaties that we have for arbitration, the moderate size of our Army, and considering all our conditions the very moderate size of our Navy, and our general indisposition to interfere in the affairs of other countries. Still, if there is more that could be said that would indicate a desire for honorable peace, it might be desirable to say it. I do not think it is likely that anything of that nature could be well dealt with in a conference. It would have to be taken up by individual nations.
[Stenographer's note: The President was asked if he had seen a certain proposal for putting an embargo on arms against aggressor countries.] Well, I have seen some reference to that. I haven't given that study enough either to come to a definite conclusion about it. It would depend very much upon the form, the details that it might take; also it would depend on what it was to be applied to. If it was to apply merely to arms and ammunition it would be taken differently in this country, than if it meant to be carried to the extent of non-intercourse, which would practically mean that we would join any other country that started a blockade on some foreign power. Whether that might involve us in an act of hostility would be something that would need to be explored. And then of course the question of what is aggression has always been one that is very difficult to determine. It is thought, I believe, that they have some formula now to the effect that it is to be the nation that refuses to arbitrate. That, I assume, would have to be modified some, because it has always been understood there were some questions of national honor and integrity that no nation ought to be called on to arbitrate or, at least, should not be held up to criticism because it refused to arbitrate such a question. I am not undertaking to go into any details or discussion, but merely indicating some of the questions that would have to be disposed of in order to come to a definite conclusion. There isn't any short cut to peace. There is no short cut to any other salvation. I think we are advised it has to be worked out with fear and trembling. I don't believe there is any way in which you can escape from that conclusion and that condition.
Source: "The Talkative President: The Off-the-Record Press Conferences of Calvin Coolidge". eds. Howard H. Quint & Robert H. Ferrell. The University Massachusetts Press. 1964.
Calvin Coolidge, Excerpts of the President's News Conference Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/349221