Most of the few existing books on naval strategy deal with it historically, by describing and explaining the naval campaigns of the past and such land campaigns as illustrate principles that apply to sea and land alike. Perhaps the best books are those of Darrieus and Mahan.

Until about fifty years ago, it was only by experience in actual war, supplemented by laborious study of the campaigns of the great commanders, and the reading of books on strategy which pointed out and expounded the principles involved in them, that one could arrive at any clear idea of strategy.

But wars have fortunately been so infrequent, the information about them has often been so conflicting, and so many results have been due to chance, that, in default of experience, the mere reading of books did not lead to very satisfactory results, except in the case of geniuses; and therefore war problems and war games were devised, in which the various factors of material and personnel were represented, and made as true to life as possible.

The tactical games resulting, which naval strategists now play, employ models of the various craft used in war, such as battleships, submarines, etc., and are governed by rules that regulate the movements of those craft on a sort of big chess-board, several feet square, that represents an area of water several miles square. The strategic games and problems are based on principles similar to those on which the tactical games are based, in the sense that actual operations are carried on in miniature; but naturally, the strategical operations cover several hundred miles, and sometimes thousands. The aim of both the tactical and the strategic games is to determine as closely as possible the laws that decide victory or defeat; and therefore, for any country, the material, personnel and operations it should employ. Naturally the results obtained are not quite so convincing as those of actual war or battle; but they are more convincing than can be attained in any other way, as yet devised, especially as many of the operations of the game-board that turn out well in games are tried out afterward by the fleet in peace maneuvers. War games and problems may be compared to the drawings that an architect makes of a house which some one wants to build; the plans and drawings are not so realistic as a real house, but they are better than anything else; and, like the war games, they can be altered and realtered until the best result seems to have been attained, considering the amount of money allowed and other practical conditions.

The idea of devising war games and war problems seems to have originated with Von Moltke; certainly it was first put in practice by his direction. Shortly after he became chief of the General Staff of the Prussian army in 1857, he set to work to carry out the ideas which he had had in mind for several years, while occupying minor posts, but which he had not had the power to enforce. It seems to have become clear to his mind that, if a chess-player acquired skill, not only by playing actual games and by studying actual games played by masters, but also by working out hypothetical chess problems, it ought to be possible to devise a system whereby army officers could supplement their necessarily meagre experience of actual war, and their necessarily limited opportunities for studying with full knowledge the actual campaigns of great strategists, by working out hypothetical, tactical, and strategic problems. Von Moltke succeeded in devising such a system and in putting it into successful operation. Hypothetical problems were prepared, in which enemy forces were confronted with each other under given circumstances of weather, terrain, and distances, each force with its objective known only to itself: for instance, you are in command of such and such a force at such and such a place; you have received orders to accomplish such and such a purpose; you receive information that the enemy, comprising such and such troops, was at a certain time at a certain place, and marching in a certain direction. What do you do?

Classes of army officers were formed, and compelled to work out the problems exactly as boys at school were compelled to work out problems in arithmetic. The skill of individual officers in solving the problems was noted and recorded; and the problems themselves, as time went on and experience was gained, were made more and more to conform to probable situations in future wars with Austria, France, and other countries, actual maps being used, and the exact nature and magnitude of every factor in each problem being precisely stated.

By such work, the pupils (officers) acquired the same kind of skill in solving strategic and tactical problems that a boy acquires in solving problems in arithmetic—a skill in handling the instruments employed. Now the skill acquired in solving any kind of problem, like the skill developed in any art, such as baseball, fencing, or piano-playing, does not give a man skill merely in doing a thing identically like a thing he has done before: such a skill would be useless, for the reason that identical conditions almost never recur, and identical problems are never presented. Similar conditions often recur, however, and similar problems are often presented; and familiarity with any class of conditions or problems imparts skill in meeting any condition or any problem that comes within that class. If, for instance, a man memorizes the sums made by adding together any two of the digits, he is equipped to master any problem of addition; and if he will practise at adding numbers together, he will gradually acquire a certain ability of mind whereby he can add together a long row of figures placed in a sequence he never saw before, and having a sum he never attained before. Or a pianist, having acquired the mastery of the technic of the keyboard and the ability to read music, can sit down before a piano he never sat at before and play off instantly a piece of music he never saw before.

Doubtless Moltke had ideas of this kind in mind when his plans for educating strategists and tacticians by problems on paper and by games were ridiculed by the unimaginative, and resisted by the indolent; and certainly no man was ever proved right more gloriously than Moltke. In the war with Austria in 1866, the Prussian army defeated the Austrian at Sadowa or Königgrätz in nineteen days after the declaration of war. In the war with France in 1870, the Prussian army routed the French and received the surrender of Napoleon III in seven weeks and two days, not because of superior courage or experience in war, but by more scientific strategy. As Henderson says: "Even the French generals of divisions and brigades had had more actual experience (in war) than those who led the German army corps. Compared with the German rank and file, a great part of their non-commissioned officers and men were veterans, and veterans who had seen much service. Their chief officers were practically familiar with the methods of moving, supplying, and maneuvering large masses of troops; their marshals were valiant and successful soldiers. And yet the history of modern warfare records no defeats so swift and complete as those of Königgrätz and Sedan. The great host of Austria was shattered in seven weeks; the French Imperial army was destroyed in seven weeks and three days; and to all intents and purposes the resistance they had offered was not much more effective than that of a respectable militia. But both the Austrian and the French armies were organized and trained under the old system. Courage, experience, and professional pride they possessed in abundance. Man for man, in all virile qualities, neither officers nor men were inferior to their foes. But one thing their generals lacked, and that was education for war. Strategy was almost a sealed book to them." Also, "Moltke committed no mistake. Long before war had been declared every possible precaution had been made. And these included much more than arrangements for rapid mobilization, the assembly of superior numbers completely organized, and the establishment of magazines. The enemy's numbers, armaments, readiness, and efficiency had been submitted to a most searching examination. Every possible movement that might be made, however unlikely, had been foreseen; every possible danger that might arise, however remote, discussed and guarded against"; also, "That the Prussian system should be imitated, and her army deprived of its monopoly of high efficiency, was naturally inevitable. Every European state has to-day its college, its intelligence department, its schools of instruction, and its course of field maneuvers and field firing."

Strategy may be divided into two parts, war strategy and preparation strategy; and of these two, preparation strategy is by far the more important.

War strategy deals with the laying out of plans of campaign after war has begun, and the handling of forces until they come into contact with the enemy, when tactics takes those forces in its charge. It deals with actual situations, arranges for the provisioning, fuelling, and moving of actual forces, contests the field against an actual enemy, the size and power of which are fairly well known—and the intentions of which are sometimes known and sometimes not. The work of the strategist in war is arduous, pressing, definite, and exciting; and results are apt to follow decisions quickly. He plays the greatest and oldest game the world has ever known, with the most elaborate instruments, and for the largest stakes. In most wars, the antagonists have been so nearly equal in point of personnel and material that the result has seemed to be decided by the relative degrees of skill of the strategists on both sides. This has been the verdict of history; and victorious commanders in all times and in all lands have achieved rarer glories, and been crowned with higher honors, than any other men.