foreign governments. The latter affects agents of foreign principals who carry on certain specified activities in the United States. Both matters are equally within the field of external affairs of this country, and, therefore, within the inherent regulatory power of the Congress.
The second foundation for the statute here under consideration is found in the powers conferred on the Congress by the Constitution to legislate concerning national defense. As indicated in United States v. Curtiss-Wright Export Corp., 299 U.S. 304, 315, 57 S.Ct. 216, 81 L.Ed. 255, the powers of the Federal government in respect to internal affairs are those that are specifically enumerated in the Constitution as well as such implied powers as are necessary and proper to carry into effect the enumerated powers. The enumerated powers areThese powers necessarily include authority to take preventive measures against activities that may cause international misunderstandings, which, in turn, may lead to war, as well as against endeavors to subvert, undermine, or overthrow the government. It is clearly within the ambit of the powers relating to national defense to legislate concerning propaganda carried on in this country by foreign agents. History demonstrates that such activities may affect the safety and the international position of this country, as was notably the fact in the episode of Citizen Genet in the early years of this republic. Such propaganda *262 may also be used to attempt to overthrow the government. The conclusion is inescapable that the statute in question is within the powers of the Congress.
This brings us to a consideration