The question has also been raised as to how far the Government is bound by the action of its negotiator provided lie has not exceeded his in structions. Formerly the rule prevailed that if the plenipotentiary acted in accordance with his full power his principal was hound by his action, since the knowledge of the full power by the other party was a motive which induced him to ne gotiate. Some writers, following the doctrines of the Roman law, still hold that the principals are in good faith bound by the acts of their duly au thorized plenipotentiaries. Others make a dis tinction in this respect between treaties proper and contracts, holding that, in view of the magni tude of the interests involved in agreements be tween States and the possibility of errors of judgment or of policy on the part of negotiators, a. right of examination and of rejection is in dispensable. It is now universally conceded that the principal may withhold his ratification from treaties negotiated strictly in pursuance of in structions where it is found to he impossible from physical or other reasons to fulfill their stipulations, o• on account of mutual error by which both parties were misled, o• where a change of circumstances upon which the validity of the treaty was made to depend has occurred, o• where ratification of the treaty would involve injury to a third party.
The extent of the treaty-making power unless restricted by the Constitution is almost unlim ited. It includes the acquisition of foreign ter ritory; the disposal of domestic territory; the recognition of new States; the creation of servi tudes; the formation of alliances; the granting of special privileges with respect to trade, com merce, and residence; the delimitation and recti fication of boundaries; the guarantee of terri torial integrity; the neutralization of ship canals, etc., etc. It is a common provision in European constitutions to restrict the treaty making power with regard to the cession of do mestic territory by requiring the approval of the legislature in such cases. A constitutional ques tion has been raised in the United States as to whether the treaty-making power extends to the alienation of land belonging to a State, and on this point constitutional lawyers differ in opin ion, but the better view seems to be that where doubt exists as to the right of a State to land which it claims the disputed territory may he eeded by treaty. On the other hand, it is con tended that land to which the right of the State is undisputed cannot be disposed of without the consent of the State except in case of conquest, where transfer is inevitable as a means of ter minating the war.
The usual conditions essential to the validity of a treaty are, first, that the contracting parties shall possess the requisite capacity for entering into treaty engagements. Thus. neutralized States like Belgium and Switzerland are lack ing in the capacity to enter into treaties which contemplate the waging of offensive war, In the second place, the plenipotentiaries who nego tiate the treaty must he properly authorized.
In the United States the President rarely if ever participates directly in the negotiations. This duty generally devolves upon the Secre tary of State, although not infrequently the work is intrusted to a minister resident or to a special plenipotentiary or commissioner. Agree meats 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 case of treaties or other agreements arisim? in the course of war, where from the na ture of 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 boundary will not affect 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 which 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 follows: (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 with 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.