On War

by Carl von Clausewitz

For combats of minor significance and importance, a mountainous country, on the other hand, may be very favourable, because the main point in them is not absolute defence, and because no decisive results are coupled with them. We may make this plainer by enumerating the objects of this reaction.

a. Merely to gain time. This motive occurs a hundred times: always in the case of a defensive line formed with the view of observation; besides that, in all cases in which a reinforcement is expected.

b. The repulse of a mere demonstration or minor enterprise of the enemy. If a province is guarded by mountains which are defended by troops, then this defence, however weak, will always suffice to prevent partisan attacks and expeditions intended to plunder the country. Without the mountains, such a weak chain of posts would be useless.

c. To make demonstrations on our own part. It will be some time yet before general opinion with respect to mountains will be brought to the right point; until then an enemy may at any time be met with who is afraid of them, and shrinks back from them in his undertakings. In such a case, therefore, the principal body may also be used for the defence of a mountain system. In wars carried on with little energy or movement, this state of things will often happen; but it must always be a condition then that we neither design to accept a general action in this mountain position, nor can be compelled to do so.

d. In general, a mountainous country is suited for all positions in which we do not intend to accept any great battle, for each of the separate parts of the army is stronger there, and it is only the whole that is weaker; besides, in such a position, it is not so easy to be suddenly attacked and forced into a decisive battle.

e. Lastly, a mountainous country is the true region for the efforts of a people in arms. But while national risings should always be supported by small bodies of regular troops, on the other hand, the proximity of a great army seems to have an unfavourable effect upon movements of this kind; this motive, therefore, as a rule, will never give occasion for transferring the whole army to the mountains.

Thus much for mountains in connection with the positions which may be taken up there for battle.

2. The influence of mountains on other parts of the country.

Because, as we have seen, it is so easy in mountainous ground to secure a considerable tract of territory by small posts, so weak in numbers that in a district easily traversed they could not maintain themselves, and would be continually exposed to danger; because every step forward in mountains which have been occupied by the enemy must be made much more slowly than in a level country, and therefore cannot be made at the same rate with him therefore the question, Who is in possession? is also much more important in reference to mountains than to any other tract of country of equal extent. In an open country, the possession may change from day to day. The mere advance of strong detachments compels the enemy to give up the country we want to occupy. But it is not so in mountains; there a very stout resistance is possible by much inferior forces, and for that reason, if we require a portion of country which includes mountains, enterprises of a special nature, formed for the purpose, and often necessitating a considerable expenditure of time as well as of men, are always required in order to obtain possession. If, therefore, the mountains of a country are not the theatre of the principal operations of a war, we cannot, as we should were it the case of a district of level country, look upon the possession of the mountains as dependent on and a necessary consequence of our success at other parts.

A mountainous district has therefore much more independence, and the possession of it is much firmer and less liable to change. If we add to this that a ridge of mountains from its crests affords a good view over the adjacent open country, whilst it remains itself veiled in obscurity, we may therefore conceive that when we are close to mountains, without being in actual possession of them, they are to be regarded as a constant source of disadvantage a sort of laboratory of hostile forces; and this will be the case in a still greater degree if the mountains are not only occupied by the enemy, but also form part of his territory. The smallest bodies of adventurous partisans always find shelter there if pursued, and can then sally forth again with impunity at other points; the largest bodies, under their cover, can approach unperceived, and our forces must, therefore, always keep at a sufficient distance if they would avoid getting within reach of their dominating influence if they would not be exposed to disadvantageous combats and sudden attacks which they cannot return.