TREATY. 438 TREATY. merits entered into in excess of their authority are invalid and ratification may be withheld. An unauthorized agreement is called a sponsion and is of no effect unless approved by the sponsor's Government. The third essential to the validity of a treaty is freedom of consent on the part of the signatory powers. If either part acts un- der constraint the resulting agreement is void except in the ease of treaties or other agreements arising in the course of war, where from the na- ture ot the case the element is present. But an error as to the value of a consideration such as may result from imperfect geographical knowl- edge with regard to a Ijouiidary will not aft'ect the validity of the treaty. Finally, treaties which stipulate for the execution of objects which are physically impossible of execution, which are re- pugnant to the usages of international law, or w-hich conflict with previous engagements with other powers are held to be invalid. Thus treaties stipulating the establishment of "slavery, assuming joint control over a portion of the high seas, or impairing the sovereignty of a third power would be invalid. Treaties are susceptible of classification along different lines. Vattel classifies them as equal and unequal, or those in which the reciprocal considerations are equal and those in which they are unequal; personal treaties, which expire with the death of the sovereign who contracts them; and real treaties, which bind the State perma- nently. De Martens follows the same arrange- ment, but adds transitory conventions and mixed treaties. Calvo distinguishes treaties, with ref- erence to their form, into transitory and per- manent; with reference to their nature, into personal and real ; with reference to their ef- fects, into equal and unequal and simple and conditional ; and, finally, with reference to their objects, into treaties of guarantee, commerce, neutrality, alliance, etc. Hall ar- ranges them as foUow's: (1) those which are declaratory of the law as understood by the con- tracting parties; (2) those which stipulate for practices which the contracting parties wish to in- corporate into the usages of law, but which they know to be outside the actual law; (3) those which are, in fact, mere bargains, in which, with- out any reference to legal considerations, some- thing is bought by one party at the price of an equivalent given by the other. Cartels, capitulations, and suspensions of arms, or truceSj .are sometimes involved in the classi- fications of treaties, although strictly speaking they are not treaties. Transitory agreements or conventions are treaties which contemplate the immediate execution of the stipulations and which are complete when this act has been per- formed. Examples are treaties of delimitation, of cession, etc. Permanent treaties are those w'hich are continuous in effect, either perpetual- ly or for a specified period. Such are treaties of amity and commerce, of neutrality, of extra- dition, postal and customs conventions, etc. Cartels are agreements entered into in time of war between the commanders of opposing armies for the purpose of eflecting an exchange of pris- oners, and they may be transitory or for the period of the war. Capitulations are similar agreements for the surrender of a place, fleet, or army. Every general commanding is pre- sumed to have authority to enter into agreements of this kind subject to any restrictions that may be imposed by the authority of his own State. A treaty of alliance is an agreement between two or more States with a view to concerted action for a certain purpose. It may be tem- porary or permanent, equal or unequal, and of- fensive or defensive or both. Defensive alliances are usually formed with a view' to preventing armed aggression against either party while of- fensive alliances are formed for the purpose of waging war against another State or States. A good example of the first class was the treaty of 1778 between the United States and France, wiiile the alliances formed among various Euro- pean States to curb the ambitions and aggres- sions of Louis XIV. and Napoleon I. were in form examples of ofl'ensive alliances, although defensive in character. Treaties of guarantee are entered into for the purpose of securing the ob- servance and execution of already existing treaties or for the maintenance of certain exist- ing conditions for a limited period or in per- petuity. Among the conditions which have been, made the subject of guarantee may be men- tioned the independence and territorial integrity of States, as, for example, Greece in 1832, and the Ottoman Empire in 1856; the neutralization of States, as in the case of Belgium and Swit- zerland; the neutralization of ship canals, as in the case of the Suez and proposed Panama canals ; the free navigation of rivers ; and the payment of State debts. VVhat are known as reciprocity treaties have been the subject of frequent negotiations in re- cent years, on account of the increasing impor- tance of international commercial relations. Such treaties provide for reciprocal commercial advantages, usually in the form of reduced cus- toms tariffs on the products of each State when imported into the other. They are usually en- tered into for limited periods of time, and are- sometimes subject to revision at stated periods. It is generally held that the special privileges granted by reciprocity treaties cannot be claimed by other States having treaties which entitle them to privileges allowed to the most favored nation, the latter class being regarded in the light of contract obligations. Treaties of peace resemble ordinary treaties in form and in sub- stance, but differ from them as regards the posi- tion of the contracting parties, since the element of duress is usually present in the negotiations, and hence freedom of conduct is not one of the requisites to the validity of such treaties. See War. As regards the preparation of treaties, it has already been said that the ordinary method of negotiation is by a regular agent or commis- sioner. During the nineteenth century, however, the preparation of a number of the most impor- tant European treaties has been intrusted to- general international congresses or conferences composed of ambassadors and in some cases of the sovereigns of the States concerned. Such were the Congress of Vienna of 1815 called to settle the questions growing out of the Napoleonic wars; the Congress of Aix-la-Chapelle in 1818, which terminated the military occupation of France; the congress at Paris in 18511. which effected a partial settlement of the Eastern Question at the close of the Crimean War and drew up a declaration relative to the usages of
