TREATY, in public law, an agreement of friendship, alliance, commerce, or naviga tion, entered into between two or more independent states. Treaties have been divided by publicists into personal and real, the difference being that the former relate exclu sively to the persons of the contracting parties—for example, treaties guaranteeing the throne to a particular sovereign and his family—and the latter are treaties for national objects, independent of the rulers of the state. While personal treaties expire with the death of the sovereign, or the extinction of his family, real treaties bind the contracting parties independently of any change iu the sovereignty of the states. The constitution of each particular state must be looked to, to determine in whom the power of negotiat ing and contracting treaties with foreign powers resides. monarchies, whether absolute or constitutional, it is usually vested in the sovereign. By the constitution of Great Britain, the exercise of this power is subject to parliamentary censure; ministers who advise the conclusion of any treaty which shall afterward be judged derogatory to the honor, or disadvantageous to the welfare of the nation, being liable to impeachment, a proceeding of which English history affords numerous instances; as the impeachment of De la Pole, earl of Suffolk, in 1451, for making a convention of peace without the assent of the privy council; of Wolsey, in 1529, by the house of lords, for making treaties without the king's knowledge; and of the earl of Orford by the commons, in 1701, for advising treaties for dividing the dominions of Spain. In republics, the chief magistrate, senate, or executive council is intrusted with the exercise of this sovereign power. The constitution of the United States of America (art. ii. sec. 2) vests it iu the president, with the advice and consent of the senate. No special form of words is necessary for the validity of a treaty; but modern usage requires that an agreement which has originally been verbal, should as soon as possible be committed to writing. There are certain compacts between nations which are included in the exercise of a general implied power confided to certain public agents as incidental to their official position. Such are the acts of generals or admirals limiting hostilities by truces, capitu
lations, or cartels for the exchange of prisoners, which do not require the ratification of the supreme authority, unless there be a reservation making that necessary. In other cases, however, a public minister or other diplomatic agent is not entitled to conclude or sign a treaty with the foreign power to which he is accredited, without a full power independent of his general letter of credence. Even in the case of a treaty concluded with full powers, it is often considered expedient to have a special ratification by the sovereign, or other proper authority of the state contracting.
A treaty is considered to be extinguished when one of the contracting powers loses its existence as an independent state, when the internal constitution of either state is changed so as to make it inapplicable; and in case of war between the contracting parties, unless the stipulations of the treaty have been expressly with a view to the rupture. As there is often a difficulty in distinguishing stipulations perpetual in their nature from those that are extinguished by war, it is common to insert clauses in treaties of peace reviving and confirming the treaties formerly subsisting between the parties.
A Treaty of guaranty is an engagement by which one state promises to aid another when it is disturbed, or threatened to be disturbed, in the peaceable enjoyment of its rights by a third power.
Treaties of alliance may be offensive or defensive: in the former, the ally engages generally to co-operate in hostilities against a specified power, or against any power with which the other may be at war; in the latter, the engagements of the ally extend only to a war of aggression commenced against the other contracting party.
The execution of a treaty is occasionally secured by hostages; as at the peace of Aix-la-Chapelle, in 1748, when several peers were sent to Paris as hostages for the restoration of cape Breton by Great Britain to France.