So we have for a third maxim of war the necessity of PROTECTED FLANKS. If we know or think that a Johnston lurks on either hand, we ought to be sure of our Pattersons; if we apprehend an unfriendly visit from a Blucher, we should see to it that our Grouchy is trustworthy. Let us now broaden our view of operations, that we may see how the principles established for a limited number of men on the march, in the field, or behind fortifications, may apply upon a larger scale. To this end a brief study of the map (9) will show four contiguous countries--‘A’, very populous, powerful and wealthy, having a navy capable of control of the high seas, and a large and efficient army; ‘C’ represents a country even more populous, but not aggressive, ‘D’ an insignificant power, while ‘B’ is a country considerable in extent, but largely mountainous, and sparsely inhabited by a rude but warlike people. A cause of war comes up between ‘A’ and ‘B’. In ancient times the ruder nation would have been the aggressor, tempted by the wealth and invited by the enervated populace of the larger civilization. Now the conditions are likely to be reversed. However, war begins; the forces of ‘A’ move hastily towards the frontier, while his fleet blockades ‘B’s’ solitary seaport at the point ‘E’. The maxim of CAUTION now naturally expands; instead of information culled by a few daring riders from a narrow circuit, it should be made to embrace the widest area of country and the utmost latitude of information--the condition of the enemy as to armament, resources, position of forces, possible disaffection among the people--everything. In war no item comes amiss. The wealthier country will here have a manifest advantage; it can afford to hire spies, and can even (as England did during the Revolution) purchase the treason of some disaffected chief. Caution for the lesser country will--if good generalship prevails--take the shape of occupying and strengthening the natural strategic positions. These are nothing but flanks of a bastion on a large scale. Upon the map round black dots represent strategic positions along the frontier. They are points susceptible of thorough fortification which control the several passes in the mountain range between the two nations; also heads of valleys, where several meet, and from which attacks could be made at will in a number of directions. This entire frontier, which may be hundreds of miles broad, is mountainous, capable of being fortified at countless points, and having natural ‘defensive relations’ needing only the art of warcraft to render them almost impregnable. Modern murderous arms lend their services more readily to defense than to offense. It is even possible that the country ‘B’, warned in due season of the purposes of her powerful rival, may have plotted out each rod of ground among those mountain passes, and that artillery service, once a matter of gunnery, has now become a matter of mathematics. [Illustration: 9]