Causes in contradistinction to Pretexts for War.
§ 64. Be that as it may, causes of war must not be confounded with pretexts for war. A State which makes war against another will never confess that there is no just cause for war, and it will therefore, when it has made up its mind to make war for political reasons, always look out for a so-called just cause. Thus frequently the apparent reason of a war is only a pretext behind which the real cause is concealed. If two States are convinced that war between them is inevitable, and if consequently they face each other armed to the teeth, they will find at the suitable time many a so-called just cause plausible and calculated to serve as a pretext for the outbreak of the war which was planned and resolved upon long ago. The skill of politics and diplomacy are nowhere more needed than on the occasion of a State's conviction that it must go to war for one reason or another. Public opinion at home and abroad is often not ripe to appreciate the reason and not prepared for the scheme of the leading politicians, whose task it is to realise their plans with the aid of pretexts which appear as the cause of war, whereas the real cause does not become apparent for some time.
Different kinds of War.
§ 65. Such writers on International Law as lay great stress upon the causes of war in general and upon the distinction between just causes and others, also lay great stress upon the distinction between different kinds of war. But as the rules of the Law of Nations are the same[77] for the different kinds of war that may be distinguished, this distinction is in most cases of no importance. Apart from that, there is no unanimity respecting the kinds of war, and it is apparent that, just as the causes of war are innumerable, so innumerable kinds of war can be distinguished. Thus one speaks of offensive and defensive, or religious, political, dynastic, national, civil wars; of wars of unity, independence, conquest, intervention, revenge, and of many other kinds. As the very name which each different kind of war bears always explains its character no further details are necessary respecting kinds of war.
Ends of War.
§ 66. The cause or causes of a war determine at its inception the ends of such war. The ends of war must not be confounded with the purpose of war.[78] Whereas the purpose of war is always the same—namely, the overpowering and utter defeat of the opponent—the ends of war may be different in each case. Ends of war are those objects for the realisation of which a war is made.[79] In the beginning of the war its ends are determined by its cause or causes, as already said. But these ends may undergo alteration, or at least modification, with the progress and development of the war. No moral or legal duty exists for a belligerent to stop the war when his opponent is ready to concede the object for which war was made. If war has once broken out the very national existence of the belligerents is more or less at stake. The risk the belligerents run, the exertion they make, the blood and wealth they sacrifice, the reputation they gain or lose through the changing fortune and chances of war—all these and many other factors work or may work together to influence the ends of a war so that eventually there is scarcely any longer a relation between them and the causes of the war. If war really were, as some writers maintain,[80] the legal remedy of self-help to obtain satisfaction for a wrong sustained from another State, no such alteration of the ends of war could take place without at once setting in the wrong such belligerent as changes the ends for which the war was initiated. But history shows that nothing of the kind is really the case, and the existing rules of International Law by no means forbid such alteration or modification of the ends of a war. This alteration or modification of the ends is the result of an alteration or modification of circumstances created during the progress of war through the factors previously mentioned; it could not be otherwise, and there is no moral, legal, or political reason why it should be otherwise. And the natural jealousy between the members of the Family of Nations, their conflicting interests in many points, and the necessity of a balance of power, are factors of sufficient strength to check the political dangers which such alteration of the ends of a war may eventually involve.
[78] Ends of war must likewise not be confounded with aims of land and sea warfare; see below, §§ [103] and [173].
[79] See Bluntschli, § 536; Lueder in Holtzendorff, IV. p. 364; Rivier, II. p. 219.