[§ 95. Commencement]
It is now assumed that peace is the normal relation of states. When these relations become strained it is customary for one or both of the states to indicate this condition by discontinuing some of the means of peaceful intercommunication, or by some act short of war. The withdrawal of a diplomatic representative, an embargo, or any similar action does not mark the commencement of war. War commences with the first act of hostilities, unless a declaration fixes an earlier date, and in case of a declaration subsequent to the first act of hostilities, war dates from the first act. A proclamation of the blockade of Cuban ports preceded the declaration of war between Spain and the United States in 1898.[294] Similarly, hostilities were begun before the declaration of war between China and Japan in 1894.[295] Indeed, few of the wars of the last two centuries have been declared before the outbreak of hostilities, and many have not been declared formally at all. Declaration at the present time is usually but a formal acknowledgment of a well-known fact. In the case of the war in South Africa, early in October, 1899, the government of the Transvaal requested the government of Great Britain to give "an immediate and affirmative answer" not later than 5 P.M. on October 11th to certain questions in the accompanying ultimatum as to settling differences by arbitration, the withdrawal of British troops, etc., stating that if the answer was not satisfactory, it would be regarded as "a formal declaration of war." The government of Great Britain replied that the conditions demanded were such that the government deemed it impossible to discuss them. Hostilities immediately followed.
Civil war naturally is not preceded by a declaration, but exists from the time of the recognition of the belligerency by an outside state, or from the date when the parent state engaged in some act of war against the insurgent party.[296] In the case of the Civil War in the United States, the proclamation of blockade of the Southern ports by President Lincoln was held to be sufficient acknowledgment of a state of war.[297]
[§ 96. Declaration]
In ancient times wars between states were entered upon with great formality. A herald whose person was inviolate brought the challenge, or formal declaration, which received reply with due formality. At the beginning of the eighteenth century this practice had become unusual, and in the days of Vattel (1714-1767) the theory of the necessity of a formal declaration was set aside. It was, however, maintained that a proclamation or manifesto should be issued for the information of the subjects of the states parties to the war, and for the information of neutrals. The practice is now generally followed, and may be regarded as obligatory.[298] Such action is reasonable in view of the changes which a state of war brings about in the relations of the parties concerned, and of neutrals. The proclamations usually specify the date from which the war begins, and hence have weight in determining the nature of acts prior to the proclamation, as the legal effects of war date from the first act of hostilities if the proclamation does not fix an earlier date. The constitution of a state, written or unwritten, determines in what hands the right to declare war shall rest, e.g. in the United States in Congress.
By act of the United States Congress of April 25, 1898,[299] it was declared:—
"First, That war be, and the same is hereby, declared to exist, and that war has existed since the twenty-first day of April, Anno Domini eighteen hundred and ninety eight, including said day, between the United States of America and the Kingdom of Spain.
"Second, That the President of the United States be, and he hereby is, directed and empowered to use the entire land and naval forces of the United States, and to call into the actual service of the United States the militia of the several States, to such extent as may be necessary to carry this Act into effect."[300]
[§ 97. Object]
The object of war may be considered from two points of view, the political and the military. International law cannot determine the limits of just objects for which a state may engage in war. Politically the objects have covered a wide range, though there is a growing tendency to limit the number of objects for which a state may go to war. It is generally held that self-preservation is a proper object, but as each state must decide for itself what threatens its existence and well-being, even this object may be very broadly interpreted. History shows that it has not been difficult from the political point of view to find an object of war when the inclination was present in the state. The nominal are often not the real objects, and the changing conditions during the progress of the war may make the final objects quite different from the initial objects. The simple cost of carrying on hostilities sometimes changes the conditions upon which peace can be made. The classification of causes and objects formerly made have little weight in determining whether a state will enter upon war. The questions of policy and conformity to current standards are the main ones at the present time.