Now if the enemy should appear with only a few hundred men, he might disperse the whole. From this has originated the expression used by historical writers, when they describe a narrow pass as a place where “a handful of men might keep an army in check.” At the same time, every one who has had any experience in war knows, or ought to know, that such a march through mountains has little or nothing in common with the attack of these same mountains, and that therefore to infer from the difficulty of marching through mountains that the difficulty of attacking them must be much greater is a false conclusion.
It is natural enough that an inexperienced person should thus argue, and it is almost as natural that the art of war itself for a certain time should have been entangled in the same error, for the fact which it related to was almost as new at that time to those accustomed to war as to the uninitiated. Before the Thirty Years’ War, owing to the deep order of battle, the numerous cavalry, the rude fire-arms, and other peculiarities, it was quite unusual to make use of formidable obstacles of ground in war, and a formal defence of mountains, at least by regular troops, was almost impossible. It was not until a more extended order of battle was introduced, and that infantry and their arms became the chief part of an army, that the use which might be made of hills and valleys occurred to men’s minds. But it was not until a hundred years afterwards, or about the middle of the eighteenth century, that the idea became fully developed.
The second circumstance, namely, the great defensive capability which might be given to a small post planted on a point difficult of access, was still more suited to lead to an exaggerated idea of the strength of mountain defences. The opinion arose that it was only necessary to multiply such a post by a certain number to make an army out of a battalion, a chain of mountains out of a mountain.
It is undeniable that a small post acquires an extraordinary strength by selecting a good position in a mountainous country. A small