INTRODUCTION
What is a State of War.
The armies of belligerent States on the outbreak of hostilities, or indeed the moment war is declared, enter into a certain relation with one another which is known by the name of “A State of War.” This relationship, which at the beginning only concerns the members of the two armies, is extended, the moment the frontier is crossed, to all inhabitants of the enemy’s State, so far as its territory is occupied; indeed it extends itself ultimately to both the movable and immovable property of the State and its citizens.
Active Persons and Passive.
A distinction is drawn between an “active” and a “passive” state of war. By the first is to be understood the relation to one another of the actual fighting organs of the two belligerents, that is to say, of the persons forming the army, besides that of the representative heads of the State and of the leaders. By the second term, i.e., the “passive” state of war, on the other hand, is to be understood the relationship of the hostile army to those inhabitants of the State, who share in the actual conduct of war only in consequence of their natural association with the army of their own State, and who on that account are only to be regarded as enemies in a passive sense. As occupying an intermediate position, one has often to take into account a number of persons who while belonging to the army do not actually participate in the conduct of hostilities but continue in the field to pursue what is to some extent a peaceful occupation, such as Army Chaplains, Doctors, Medical Officers of Health, Hospital Nurses, Voluntary Nurses, and other Officials, Sutlers, Contractors, Newspaper Correspondents and the like.
That War is no Respecter of Persons.
Now although according to the modern conception of war, it is primarily concerned with the persons belonging to the opposing armies, yet no citizen or inhabitant of a State occupied by a hostile army can altogether escape the burdens, restrictions, sacrifices, and inconveniences which are the natural consequence of a State of War. A war conducted with energy cannot be directed merely against the combatants of the Enemy State and the positions they occupy, but it will and must in like manner seek to destroy the total intellectual[38] and material resources of the latter.[39] Humanitarian claims such as the protection of men and their goods can only be taken into consideration in so far as the nature and object of the war permit.
The Usages of War.
Consequently the “argument of war” permits every belligerent State to have recourse to all means which enable it to attain the object of the war; still, practise has taught the advisability of allowing in one’s own interest the introduction of a limitation in the use of certain methods of war and a total renunciation of the use of others. Chivalrous feelings, Christian thought, higher civilization and, by no means least of all, the recognition of one’s own advantage, have led to a voluntary and self-imposed limitation, the necessity of which is to-day tacitly recognized by all States and their armies. They have led in the course of time, in the simple transmission of knightly usage in the passages of arms, to a series of agreements, hallowed by tradition, and we are accustomed to sum these up in the words “usage of war” (Kriegsbrauch), “custom of war” (Kriegssitte), “or fashion of war” (Kriegsmanier). Customs of this kind have always existed, even in the times of antiquity; they differed according to the civilization of the different nations and their public economy, they were not always identical, even in one and the same conflict, and they have in the course of time often changed; they are older than any scientific law of war, they have come down to us unwritten, and moreover they maintain themselves in full vitality; they have therefore won an assured position in standing armies according as these latter have been introduced into the systems of almost every European State.
Of the futility of Written Agreements as Scraps of Paper.