(b) The agents acting for the state must be duly authorized, i.e. the plenipotentiaries must act within their powers.

(c) There must be freedom of consent in the agreements between the states. This does not imply that force, as by war, reprisals, or otherwise, may not be used in bringing about a condition of affairs which may lead a state, without parting with its independence, to make such sacrifices as may be necessary to put an end thereto. No constraint can be put upon the negotiators of the treaty by threats of personal violence, or in any way to prohibit their free action, without invalidating their acts. There is no freedom of consent when the agreement is reached through fraud of either party, and treaties so obtained are not valid.

(d) The treaties must be in conformity to law, as embodied in the generally recognized principles of international law and the established usage of states. States could not by treaty appropriate the open sea, protect the slave trade, partition other states unless as a measure of self-protection, deprive subjects of essential rights of humanity, or enter into other agreements that could not be internationally obligatory.

§ 85. Classification of Treaties

Treaties have been variously classified, but the classifications serve no great purpose. The most common classification is clearly set forth by Calvo. As regards form, treaties may be, (1) transitory, or (2) permanent or perpetual; as regards nature, (1) personal, relating to the sovereign, or (2) real, relating to things and not

dependent on the sovereign person; as regards effects, (1) equal or (2) unequal, or according to other effects, simple or conditional, definitive or preliminary, principal or accessory, etc.; as regards objects, (1) general or (2) special.1 In a narrower sense treaties may be divided into many classes, as political, economic, guarantee, surety, neutrality, alliance, friendship, boundary, cession, exchange, jurisdiction, extradition, commerce, navigation, peace, etc., and conventions relating to property of various kinds, including literary and artistic, to post and telegraph, etc. Most of these classes are sufficiently described by their titles. The nature of some of the classes is not fully indicated in the title.

A treaty of guarantee is an engagement by which a state agrees to secure another in the possession of certain specified rights, as in the exercise of a certain form of government, in the free exercise of authority within its dominions, in freedom from attack, in the free navigation of specified rivers, in the exercise of neutrality, etc. In 1831 and 1839, by the Treaties of London, the independence and neutrality of Belgium were guaranteed, and in the Treaty of 1832 the affairs in Greece were adjusted under guarantee. The Treaty of Paris, 1856, guarantees "the independence and the integrity of the Ottoman Empire." When the guaranteeing state is not only bound to use its best efforts to secure the fulfillment of the treaty stipulations, but to make good the conditions agreed upon in the treaty provided one of the principals fails to meet its obligations, the treaty is not merely one of guarantee, but also a treaty 1 Calvo, §§ 643-668.

of surety. This happens in case of loans more particularly.

Agreements of states to act together for specific or general objects constitute treaties of alliance. The nature of these treaties of alliance varies with the terms. They may be defensive, offensive, equal, unequal, general, special, permanent, temporary, etc., or may combine several of these characteristics.

§ 86. Interpretation of Treaties

Sometimes clauses interpreting treaties are discussed and adopted by the states signing a treaty. These acts may take the form of notes, protocols, declarations, etc. The dispatch of the French ambassador at London, Aug. 9, 1870, to the foreign secretary interprets certain clauses of the treaty guaranteeing the neutrality of Belgium. In cases where no preliminary agreement in regard to interpretation is made. there are certain general principles of interpretation which are ordinarily accepted. Many treatises follow closely the chapters of Grotius and Vattel upon this subject.1

The rules usually accepted are: (1) Words of the treaty are to be taken in the ordinary and reasonable sense as when elsewhere used under similar conditions. (2) If the words have different meanings in the different states, the treaty should so far as possible be construed so as to accord with the meaning of the words

1 Grotius, II., 16; Vattel, II., 17. The rules of Vattel are briefly and well stated by Baker, "First Steps in International Law," 1899, p. 105.

in the states which accepted the conditions. (3) In default of a plain meaning, the spirit of the treaty or a reasonable meaning should prevail. (4) Unless the fundamental rights of states are expressly the subject of the agreement, these rights are not involved. (5) That which is clearly granted by the treaty carries with it what is necessary for its realization.

In the cases of conflicting clauses in a single treaty or conflicting treaties, the general rules are: (1) Special clauses prevail against general clauses; prohibitory against permissive, unless the prohibitory is general and the permissive special; of two prohibitory clauses, the one more distinctly mandatory prevails; of two similar obligatory clauses the state in whose favor the obligation runs may choose which shall be observed. (2) In case of conflict in treaties between the same states the later prevails; in case a later treaty with a third state conflicts with an earlier treaty with other states, the earlier treaty prevails.1

"The most favored nation" clause is now common in treaties of commercial nature. This clause ordinarily binds the state to grant to its co-signer all the privileges similarly granted to all other states, and such as shall be granted under subsequent treaties. When privileges are granted by one state in exchange for privileges granted by another, as in a reciprocal reduction in tariff duties, a third state can lay claim to like reduction only upon fulfillment of like conditions. Under "the most favored nation" clause, Art. VIII., of the

1 For the subject of interpretation, see Hall, §§ 111, 112, p. 350 ff. ; 2 Phillimore, Pt. V., Ch. VIII.; Calvo, §§ 1649–1650; Pradier-Fodéré, §§ 1171-1188.

Treaty of 1803, between France and the United States, France claimed that its ships were entitled to all the privileges granted to any other nation whether so granted in return for special concessions or not. This position the United States refused to accept, and by Article VII. of the Treaty of 1831 France renounced the claims.1

§ 87. Termination of Treaties

Treaties in general come to an end under the following conditions:

(a) The complete fulfillment of all the treaty stipulations terminates a treaty.

(b) The expiration of the limit of time for which the treaty agreement was made puts an end to the treaty.

(c) A treaty may be terminated by express agreement of the parties to it.

(d) When a treaty depends upon the execution of conditions contrary to the principles of international law or morality or impossible of performance, it is not effective.

(e) A state may renounce the advantages and rights secured under a treaty, e.g. England renounced the protectorate of the Ionian Islands in 1864, which she had held since 1815.

(f) A declaration of war may put an end to those treaties which have regard only to conditions of peaceful relations, as treaties of alliance, commerce, navigation, etc., and may suspend treaties which have regard

1 For discussion of the "most favored nation" clause, see 2 Whart., § 134, also Appendix to Vol. III., p. 888, and J. R. Harod, "Favored Nation Treatment."