[Sidenote:  Declaration of War]

Declarations have existed from the most ancient times, having been borrowed by modern nations from the manners and customs of the Romans.  But in present times, (although they may be very properly put forward,) they are not necessary to a state of actual war, or as it is technically termed, to legalize hostilities.  A Declaration of War is not a matter of international right.[4] Acts of hostilities, without such an instrument, cannot be denounced as irregular or piratical, unless committed in manifest bad faith.  But though war may lawfully commence without an actual declaration, yet a declaration is of sufficient force to create a state of war, without any mutual attack.  It is not a mere challenge from one country to another, to be accepted or refused at pleasure by the other.  It proves the existence of actual hostilities on one side at least, and puts the other party also in a state of war, though, he may, perhaps, think proper to act on the defensive only.[5]

[Sidenote:  War, how commenced.]

War now generally commences by Actual Hostilities, by the Recal or Dismissal of an Ambassador or Minister, or by a Manifesto published by one belligerent power to its own subjects.

Manifestoes are issued to fix the date of the commencement of hostilities; for as a state of war has many various effects on commercial transactions, such as the confiscation of certain property, and the dissolution of certain contracts, it is very necessary that such a date should be accurately known.  When a Manifesto or Declaration is issued, it is said to legalize hostilities, that is to say,—­to make all acts done, and all breaches committed, under pressure of war, good and lawful acts and breaches.

I have given this explanation, because it is a popular notion that a declaration always precedes war; but in reality, in modern times, few wars are solemnly declared;—­they begin most often with general hostilities; thus the first Dutch War began upon general Letters of Marque, and the War with Spain, that commenced by the attempted invasion of the Armada in 1588, was not declared or proclaimed between the two crowns.[6]

[Sidenote:  Contents of Declaration.]

The Manifesto not only announces the commencement Contents of and existence of hostilities, but also states the reasons of, and attempts the justification of the war; and it is necessary for the instruction and direction of the subjects of the belligerent state, with respect to their intercourse with the foe; it also apprizes neutral nations of the fact, and enables them to conform their conduct to the rights belonging to the new state of things.[7]

Without such an official act, it might be difficult to distinguish, in a Treaty of Peace, those acts which are to be accounted lawful effects of war, from those which either nation may consider as naked wrongs, and for which they may, under certain circumstances, claim reparation.