Strategy is difficult of definition; but though many definitions have been made, and though they do not agree together very well, yet all agree that strategy is concerned with the preparation of military forces for war and for operating them in war—while tactics is the immediate instrument for handling them in battle. Strategy thinks out a situation beforehand, and decides what preparations as to material, personnel, and operations should be made.
Many books have been written on strategy, meaning strategy as applied to armies, but very few books have been written on naval strategy. The obvious reasons are that armies in the past have been much larger and more important than navies; that naval men have only recently had the appliances on board ship for writing on an extensive scale; and that the nature of their occupation has been such that continuous application of the kind needed for thinking out principles and expounding them in books, has only recently been possible.
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