Grotius, II. c. 15, § 5—Vattel, II. § 153—Hall, § 109—Westlake, I. pp. 279-281—Wheaton, § 253—Moore, V. § 740—Bluntschli, §§ 417-427—Hartmann, §§ 46-47—Heffter, §§ 87-91—Ullmann, § 80—Bonfils, Nos. 821-823—Pradier-Fodéré, II. Nos. 1084-1099—Mérignhac, II. p. 645—Rivier, II. pp. 64-68—Nys, III. pp. 25-28—Fiore, II. Nos. 1004-1006, and Code, Nos. 759-763—Martens, I. § 112—Jellinek, "Die rechtliche Natur der Staatenverträge" (1880), p. 56—Nippold, op. cit. pp. 178-181.
No necessary Form of Treaties.
§ 507. The Law of Nations includes no rule which prescribes a necessary form of treaties. A treaty is, therefore, concluded as soon as the mutual consent of the parties becomes clearly apparent. Such consent must always be given expressly, for a treaty cannot be concluded by tacit consent. But it matters not whether an agreement is made in writing, orally, or by symbols. Thus, in time of war, the exhibition of a white flag symbolises the proposal of an agreement as to a brief truce for the purpose of certain negotiations, and the acceptance of the proposal on the part of the other side by the exhibition of a similar symbol establishes a convention as binding as any written treaty. Thus, too, history tells of an oral treaty of alliance, secured by an oath, concluded in 1697 at Pillau between Peter the Great of Russia and Frederick III., Elector of Brandenburg.[864] Again, treaties are sometimes concluded through an exchange of diplomatic notes between the Secretaries for Foreign Affairs of two States or through the exchange of personal letters between the heads of two States. However, as a matter of reason, treaties usually take the form of a written[865] document signed by duly authorised representatives of the contracting parties.
[864] See Martens, I. § 112.
[865] The only writer who nowadays insists upon a written agreement for a treaty to be valid is, as far as I know, Bulmerincq (§ 56). But although all important treaties are naturally concluded in writing, the example of the agreements concluded between armed forces in time of war either orally or through symbols proves that the written form is not absolutely necessary.
Acts, Conventions, Declarations.
§ 508. International compacts which take the form of written contracts, are, besides Agreements or Treaties, sometimes termed Acts, sometimes Conventions, sometimes Declarations. But there is no essential difference between them, and their binding force upon the contracting parties is the same whatever be their name. The Geneva Convention, the Declarations of Paris and of London, and the Final Act of the Vienna Congress are as binding as any agreement which goes under the name of "Treaty" or "Convention." The attempt[866] to distinguish fundamentally between a "Declaration" and a "Convention" by maintaining that whereas a "Convention" creates rules of particular International Law between the contracting States only, a "Declaration" contains the recognition, on the part of the best qualified and most interested Powers, of rules of universal International Law, does not stand the test of scientific criticism. A "Declaration" is nothing else but the title of a law-making treaty according to which the parties engage themselves to pursue in future a certain line of conduct.[867] But such law-making treaties are quite as frequently styled "Conventions" as "Declarations." The best example is the Hague "Convention" concerning the laws and usages of war, which is based upon the unratified "Declaration" concerning the laws and customs of war produced by the Brussels Conference of 1874.
[866] On the part of the British Foreign Office, see Parliamentary Papers, Miscellaneous, No. 5 (1909), Cd. 4555, Proceedings of the International Naval Conference held in London, December 1908-1909, p. 57.
Parts of Treaties.