Roosevelt, President of the United States of America, acting under and by virtue of the authority conferred in me by the said joint resolution of Congress, do hereby declare and proclaim that I have found that the prohibition of the sale of arms and munitions of war in the United States to those countries now engaged in armed conflict in the Chaco may contribute to the reestablishment of peace between those countries, and that I have consulted with the governments of other American Republics and have been assured of the cooperation of such governments as I have deemed necessary as contemplated by the said joint resolution; and I do hereby admonish all citizens of the United States and every person to abstain from every violation of the provisions of the joint resolution above set forth, hereby made applicable to Bolivia and Paraguay, and I do hereby warn them that all violations of such provisions will be rigorously prosecuted." . . .
First. It is contended that by the joint Resolution the going into effect and continued operation of the resolution was conditioned (a) upon the President's judgment as to its beneficial effect upon the re-establishment of peace between the countries engaged in armed conflict in the Chaco; (b) upon the making of a proclamation, which was left to his unfettered discretion, thus constituting an attempted substitution of the President's will for that of Congress; (c) upon the making of a proclamation putting an end to the operation of the resolution, which again was left to the President's unfettered discretion; and (d) further, that the extent of its operation in particular cases was subject to limitation and exception by the President, controlled by no standard. In each of these particulars, appellees urge that Congress abdicated its essential functions and delegated them to the Executive.
Whether, if the joint Resolution had related solely to internal affairs, it would be open to the challenge that it constituted an unlawful delegation of legislative power to the Executive, we find it unnecessary to determine. The whole aim of the resolution is to affect a situation entirely external to the United States, and falling within the category of foreign affairs. The determination which we are called to make, therefore, is whether the Joint Resolution, as applied to that situation, is vulnerable to attack under the rule that forbids a delegation of the lawmaking power. In other words, assuming (but not deciding) that the challenged delegation, if it were confined to internal affairs, would be invalid, may it nevertheless be sustained on the ground that its exclusive aim is to afford a remedy for a hurtful condition within foreign territory?
It will contribute to the elucidation of the question if we first consider the differences between the powers of the federal government in respect of foreign or external affairs and those in respect of domestic or internal affairs. That there are differences between them, and that these differences are fundamental, may not be doubted.
The two classes of powers are different, both in respect of their origin and their nature. The broad statement that the federal government can exercise no powers except those specifically enumerated in the Constitution, and such implied powers as are necessary and proper to carry into effect the enumerated powers, is categorically true only in respect of our internal affairs. In that field, the primary purpose of the Constitution was to carve from the general mass of legislative powers then possessed by the states such portions as it was thought desirable to vest in the federal government, leaving those not included in the enumeration still in the states. Carter v. Carter Coal Co. . . . That