The Influence of Sea Power upon History. Alfred Thayer Mahan
seek to pass through the Channel to effect a junction with its ally. On either side, also, Nature gave her better ports and a safer coast to approach. Formerly this was a very serious element in the passage through the Channel but of late, steam and the improvement of her harbors have lessened the disadvantage under which France once labored. In the days of sailing-ships, the English fleet operated against Brest making its base at Torbay and Plymouth. The plan was simply this: in easterly or moderate weather the blockading fleet kept its position without difficulty but in westerly gales, when too severe, they bore up for English ports, knowing that the French fleet could not get out till the wind shifted, which equally served to bring them back to their station.
The advantage of geographical nearness to an enemy, or to the object of attack, is nowhere more apparent than in that form of warfare which has lately received the name of commerce-destroying, which the French call _guerre de course_. This operation of war, being directed against peaceful merchant vessels which are usually defenceless, calls for ships of small military force. Such ships, having little power to defend themselves, need a refuge or point of support near at hand; which will be found either in certain parts of the sea controlled by the fighting ships of their country, or in friendly harbors. The latter give the strongest support, because they are always in the same place, and the approaches to them are more familiar to the commerce-destroyer than to his enemy. The nearness of France to England has thus greatly facilitated her _guerre de course_ directed against the latter. Having ports on the North Sea, on the Channel, and on the Atlantic, her cruisers started from points near the focus of English trade, both coming and going. The distance of these ports from each other, disadvantageous for regular military combinations, is an advantage for this irregular secondary operation; for the essence of the one is concentration of effort, whereas for commerce-destroying diffusion of effort is the rule. Commerce-destroyers scatter, that they may see and seize more prey. These truths receive illustration from the history of the great French privateers, whose bases and scenes of action were largely on the Channel and North Sea, or else were found in distant colonial regions, where islands like Guadaloupe and Martinique afforded similar near refuge. The necessity of renewing coal makes the cruiser of the present day even more dependent than of old on his port. Public opinion in the United States has great faith in war directed against an enemy's commerce but it must be remembered that the Republic has no ports very near the great centres of trade abroad. Her geographical position is therefore singularly disadvantageous for carrying on successful commerce-destroying, unless she find bases in the ports of an ally.
If, in addition to facility for offence, Nature has so placed a country that it has easy access to the high sea itself, while at the same time it controls one of the great thoroughfares or the world's traffic, it is evident that the strategic value of its position is very high. Such again is, and to a greater degree was, the position of England. The trade of Holland, Sweden, Russia, Denmark, and that which went up the great rivers to the interior of Germany, had to pass through the Channel close by her doors; for sailing-ships hugged the English coast. This northern trade had, moreover, a peculiar bearing upon sea power for naval stores, as they are commonly called, were mainly drawn from the Baltic countries.
But for the loss of Gibraltar, the position of Spain would have been closely analogous to that of England. Looking at once upon the Atlantic and the Mediterranean, with Cadiz on the one side and Cartagena on the other, the trade to the Levant must have passed under her hands, and that round the Cape of Good Hope not far from her doors. But Gibraltar not only deprived her of the control of the Straits, it also imposed an obstacle to the easy junction of the two divisions of her fleet.
At the present day, looking only at the geographical position of Italy, and not at the other conditions affecting her sea power, it would seem that with her extensive sea-coast and good ports she is very well placed for exerting a decisive influence on the trade route to the Levant and by the Isthmus of Suez. This is true in a degree, and would be much more so did Italy now hold all the islands naturally Italian; but with Malta in the hands of England, and Corsica in those of France, the advantages of her geographical position are largely neutralized. From race affinities and situation those two islands are as legitimately objects of desire to Italy as Gibraltar is to Spain. If the Adriatic were a great highway of commerce, Italy's position would be still more influential. These defects in her geographical completeness, combined with other causes injurious to a full and secure development of sea power, make it more than doubtful whether Italy can for some time be in the front rank among the sea nations.
As the aim here is not an exhaustive discussion, but merely an attempt to show, by illustration, how vitally the situation of a country may affect its career upon the sea, this division of the subject may be dismissed for the present; the more so as instances which will further bring out its importance will continually recur in the historical treatment. Two remarks, however, are here appropriate.
Circumstances have caused the Mediterranean Sea to play a greater part in the history of the world, both in a commercial and a military point of view, than any other sheet of water of the same size. Nation after nation has striven to control it, and the strife still goes on. Therefore a study of the conditions upon which preponderance in its waters has rested, and now rests, and of the relative military values of different points upon its coasts, will be more instructive than the same amount of effort expended in another field. Furthermore, it has at the present time a very marked analogy in many respects to the Caribbean Sea, an analogy which will be still closer if a Panama canal-route ever be completed. A study of the strategic conditions of the Mediterranean, which have received ample illustration, will be an excellent prelude to a similar study of the Caribbean, which has comparatively little history.
The second remark bears upon the geographical position of the United States relatively to a Central-American canal. If one be made, and fulfil the hopes of its builders, the Caribbean will be changed from a terminus, and place of local traffic, or at best a broken and imperfect line of travel, as it now is, into one of the great highways of the world. Along this path a great commerce will travel, bringing the interests of the other great nations, the European nations, close along our shores, as they have never been before. With this it will not be so easy as heretofore to stand aloof from international complications. The position of the United States with reference to this route will resemble that of England to the Channel, and of the Mediterranean countries to the Suez route. As regards influence and control over it, depending upon geographical position, it is of course plain that the centre of the national power, the permanent base,[1] is much nearer than that of other great nations. The positions now or hereafter occupied by them on island or mainland, however strong, will be but outposts of their power; while in all the raw materials of military strength no nation is superior to the United States. She is, however, weak in a confessed unpreparedness for war; and her geographical nearness to the point of contention loses some of its value by the character of the Gulf coast, which is deficient in ports combining security from an enemy with facility for repairing war-ships of the first class, without which ships no country can pretend to control any part of the sea. In case of a contest for supremacy in the Caribbean, it seems evident from the depth of the South Pass of the Mississippi, the nearness of New Orleans, and the advantages of the Mississippi Valley for water transit, that the main effort of the country must pour down that valley, and its permanent base of operations be found there. The defence of the entrance to the Mississippi, however, presents peculiar difficulties; while the only two rival ports, Key West and Pensacola, have too little depth of water, and are much less advantageously placed with reference to the resources of the country. To get the full benefit of superior geographical position, these defects must be overcome. Furthermore, as her distance from the Isthmus, though relatively less, is still considerable, the United States will have to obtain in the Caribbean stations fit for contingent, or secondary, bases of operations; which by their natural advantages, susceptibility of defence, and nearness to the central strategic issue, will enable her fleets to remain as near the scene as any opponent. With ingress and egress from the Mississippi sufficiently protected, with such outposts in her hands, and with the communications between them and the home base secured, in short, with proper military preparation, for which she has all necessary means, the preponderance of the United States on this field follows, from her geographical position and her power, with mathematical certainty.
II. Physical Conformation. The peculiar features of the