I. It will prove a very interesting and strengthening mental exercise to apply these few leading principles to every campaign we read about, to search for indications of their application in the strategy of each belligerent, how far each commander succeeded, and how far failed to carry them out in their entirety, and where, when, and why he succeeded or failed, and the results of doing or not doing so. Also to search for the interaction of the political motive of the war on the military operations, and to see how far the belligerent statesmen gained or failed to gain their political object, according to the comparative degree of preparation they had made for it, and the magnitude of effort which they made or did not make to support it with the whole means of the nation, material, moral and physical. Also to see how far the national spirit was aroused or not, and the causes thereof, and to note the greater or less energy, resolution and boldness which was consequently infused into the war. Also to note how the thorough application of these great simple principles of strategy shortens the war and thereby reduces its cost (1866 to 1870), and how the neglect of them by statesmen, despite their fortitude afterwards, lengthens a war and adds to its cost enormously (South Africa, etc.). Used thus, these principles give us a theoretically correct ground for criticism. II. These principles also give us a theoretically correct ground for anticipating what the action of our opponents in any future war will be, the measure of the forces they will bring to bear, how they will direct those forces, and the amount of energy, resolution, and boldness with which they will use them against us. It is an axiom always to assume that the enemy will do the best and wisest thing, and to prepare accordingly. III. These principles also give us a theoretically correct ground for our own counter-preparations. We require to take the most dangerous war which is probable or possible, and make every imaginable preparation to carry out these principles therein.