§ 21. If the Law of Nations and Municipal Law differ as demonstrated, the Law of Nations can neither as a body nor in parts be per se a part of Municipal Law. Just as Municipal Law lacks the power of altering or creating rules of International Law, so the latter lacks absolutely the power of altering or creating rules of Municipal Law. If, according to the Municipal Law of an individual State, the Law of Nations as a body or in parts is considered the law of the land, this can only be so either by municipal custom or by statute, and then the respective rules of the Law of Nations have by adoption[22] become at the same time rules of Municipal Law. Wherever and whenever such total or partial adoption has not taken place, municipal courts cannot be considered to be bound by International Law, because it has, per se, no power over municipal courts.[23] And if it happens that a rule of Municipal Law is in indubitable conflict with a rule of the Law of Nations, municipal courts must apply the former. If, on the other hand, a rule of the Law of Nations regulates a fact without conflicting with, but without expressly or tacitly having been adopted by Municipal Law, municipal courts cannot apply such rule of the Law of Nations.
[22] This has been done by the United States. See The Nereide, 9 Cranch, 388; United States v. Smith, 5 Wheaton, 153; The Scotia, 14 Wallace, 170; The Paquette Habana, 175 United States, 677. See also Taylor, § 103, and Scott in A.J.I. (1908), pp. 852-865. As regards Great Britain, see Blackstone, IV. ch. 5, and Westlake in The Law Quarterly Review, XXII. (1906), pp. 14-26; see also the case of the West Rand Central Mining Co. v. The King (1905), 2 K. B. 391.
[23] This ought to be generally recognised, but, in fact, is not; says, for instance, Kohler in Z.V. II.(1908), p. 210:—"... das Völkerrecht ist ein überstaatliches Recht, das der Gesetzgebung des einzelnen Staates nicht unterworfen ist und von den Richtern ohne weiteres respectirt werden muss: das Völkerrecht steht über dem staatlichen Recht."
Certain Rules of Municipal Law necessitated or interdicted.
§ 22. If Municipal Courts cannot apply unadopted rules of the Law of Nations, and must apply even such rules of Municipal Law as conflict with the Law of Nations, it is evident that the several States, in order to fulfil their international obligations, are compelled to possess certain rules, and are prevented from having certain other rules as part of their Municipal Law. It is not necessary to enumerate all the rules of Municipal Law which a State must possess, and all those rules it is prevented from having. It suffices to give some illustrative examples. Thus, on the one hand, the Municipal Law of every State, for instance, is compelled to possess rules granting the necessary privileges to foreign diplomatic envoys, protecting the life and liberty of foreign citizens residing on its territory, threatening punishment for certain acts committed on its territory in violation of a foreign State. On the other hand, the Municipal Law of every State is prevented by the Law of Nations from having rules, for instance, conflicting with the freedom of the high seas, or prohibiting the innocent passage of foreign merchantmen through its maritime belt, or refusing justice to foreign residents with regard to injuries committed on its territory to their lives, liberty, and property by its own citizens. If a State does nevertheless possess such rules of Municipal Law as it is prevented from having by the Law of Nations, or if it does not possess such Municipal rules as it is compelled to have by the Law of Nations, it violates an international legal duty, but its courts[24] cannot by themselves alter the Municipal Law to meet the requirements of the Law of Nations.
[24] This became quite apparent in the Moray Firth case (Mortensen v. Peters)—see below, § [192]—in which the Court had to apply British Municipal Law.
Presumption against conflicts between International and Municipal Law.
§ 23. However, although Municipal Courts must apply Municipal Law even if conflicting with the Law of Nations, there is a presumption against the existence of such a conflict. As the Law of Nations is based upon the common consent of the different States, it is improbable that a civilised State would intentionally enact a rule conflicting with the Law of Nations. A part of Municipal Law, which ostensibly seems to conflict with the Law of Nations, must, therefore, if possible, always be so interpreted as essentially not containing such conflict.
Presumption of Existence of certain necessary Municipal Rules.
§ 24. In case of a gap in the statutes of a civilised State regarding certain rules necessitated by the Law of Nations, such rules ought to be presumed by the Courts to have been tacitly adopted by such Municipal Law. It may be taken for granted that a State which is a member of the Family of Nations does not intentionally want its Municipal Law to be deficient in such rules. If, for instance, the Municipal Law of a State does not by a statute grant the necessary privileges to diplomatic envoys, the courts ought to presume that such privileges are tacitly granted.