Lessons of the war with Spain and other articles. A. T. Mahan

widely divergent one from the other, both in geographical position and in method of action; namely, the attack upon Cuba and the protection of its own shores. As the defences did not inspire confidence, the navy had to supplement their weakness, although it is essentially an offensive, and not a defensive, organization. Upon this the enemy counted much at the first. "To defend the Atlantic coasts in case of war," wrote a Spanish lieutenant who had been Naval Attaché in Washington, "the United States will need one squadron to protect the port of New York and another for the Gulf of Mexico. But if the squadron which it now possesses is devoted to the defence of New York (including Long Island Sound), the coasts of the Gulf of Mexico must be entirely abandoned and left at the mercy of blockade and bombardment." Our total force for the order of battle, prior to the arrival of the Oregon, was nominally only equal to that of the enemy, and, when divided between the two objects named, the halves were not decisively superior to the single squadron under Cervera—which also might be reinforced by some of the armored ships then in Spain. The situation, therefore, was one that is not infrequent, but always embarrassing—a double purpose and a single force, which, although divisible, ought not to be divided.

      It is proper here to say, for the remark is both pertinent and most important, that coast defences and naval force are not interchangeable things; neither are they opponents, one of the other, but complementary. The one is stationary, the other mobile; and, however perfect in itself either may be, the other is necessary to its completeness. In different nations the relative consequence of the two may vary. In Great Britain, whose people are fed, and their raw materials obtained, from the outside world, the need for a fleet vastly exceeds that for coast defences. With us, able to live off ourselves, there is more approach to parity. Men may even differ as to which is the more important; but such difference, in this question, which is purely military, is not according to knowledge. In equal amounts, mobile offensive power is always, and under all conditions, more effective to the ends of war than stationary defensive power. Why, then, provide the latter? Because mobile force, whatever shape it take, ships or men, is limited narrowly as to the weight it can bear; whereas stationary force, generally, being tied to the earth, is restricted in the same direction only by the ability of the designer to cope with the conditions. Given a firm foundation, which practically can always be had, and there is no limit to the amount of armor—mere defensive outfit—be it wood, stone, bricks, or iron, that you can erect upon it; neither is there any limit to the weight of guns, the offensive element, that the earth can bear; only they will be motionless guns. The power of a steam navy to move is practically unfettered; its ability to carry weight, whether guns or armor, is comparatively very small. Fortifications, on the contrary, have almost unbounded power to bear weight, whereas their power to move is nil; which again amounts to saying that, being chained, they can put forth offensive power only at arm's length, as it were. Thus stated, it is seen that these two elements of sea warfare are in the strictest sense complementary, one possessing what the other has not; and that the difference is fundamental, essential, unchangeable—not accidental or temporary. Given local conditions which are generally to be found, greater power, defensive and offensive, can be established in permanent works than can be brought to the spot by fleets. When, therefore, circumstances permit ships to be squarely pitted against fortifications—not merely to pass swiftly by them—it is only because the builders of the shore works have not, for some reason, possibly quite adequate, given them the power to repel attack which they might have had. It will not be asserted that there are no exceptions to this, as to most general rules; but as a broad statement it is almost universally true. "I took the liberty to observe," wrote Nelson at the siege of Calvi, when the commanding general suggested that some vessels might batter the forts, "that the business of laying wood against walls was much altered of late." Precisely what was in his mind when he said "of late" does not appear, but the phrase itself shows that the conditions which induced any momentary equality between ships and forts when brought within range were essentially transient.