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Captain Alfred T. Mahan to the Naval War Board

Navy Department,


Washington, D. C.,               

July 18th 1898



          The condition of things now under deliberation may be summarized thus:

     The United States, having definitely established naval preponderance over the enemy, and with it the control of the sea, in the military sense, wishes to do two things:1

1. Proceed against Porto Rico, including therein the capture of the Capital, San Juan.2

2. Send a reinforcement, of at least two battleships, to Dewey at Manila.3

This second object, however, is more properly stated in the terms of its principal difficulty, thus:  The United States wishes to send a Division of two battleships4 through the Straits of Gibralter, the place where such naval strength as remains to Spain can be most effectively concentrated.5

The true strategy of the Spanish navy, under the apprehension now entertained of bombardment of coast cities, would be as follows:

The most important of exposed cities, Cadiz, Malaga and Barcelona, are within, or close to the Straits of Gibralter; consequently the best defence for those cities would be to concentrate the entire available navy at Cadiz;6 whence, with proper scrutiny, it could be thrown against our force in the straits, or at the least follow it so closely as to bring it to action before harm could be done.

It matters not the least that the Spanish fleet, by pursuing this course, may be beaten. It is its proper course, which it cannot refuse without shame.

Now, if the enemy should penetrate our ultimate design of sending these ships to Manila, the same course is incumbent,- concentration at Cadiz, and attack in the Straits, is his proper course.

We may believe that our Division, increased as proposed to three, by the addition of the Brooklyn, would emerge victorious from such attack; but we have no right to assume that at least one ship would not be seriously injured. Two shells struck the Iowa on July 3rd, and several the Brooklyn.7

I submit that the crucial feature of the whole situation, military and diplomatic, at present, is the control of the sea; and that while we unquestionably possess it, as against Spain, we have no such margin as justifies a risk without adequate gain.8 No other battleship is promised before eight months, and such promises are rarely fulfilled as to date.9

Per contra, reverting to the first object of the United States, what role are the Battleships, as distinguished from Monitors, to perform at Porto Rico?

To my mind, none. There is an evident hint, in more quarters than one, that they are to engage the sea coast batteries of San Juan. To any such course, I record my emphatic dissent. The teaching of the war, so far, is that such attacks are useless; and if we persist, we will get the further teaching that they are dangerous to ships far beyond the point of any possible gain from them.10

By doing this, as well as by sending a Division of three through the Straits of Gibralter, we run a needless risk of injury to battleships, for which injury there is no prospective compensation. Disable your battleships, and you will soon find a change in your diplomacy.11 I have no objection to risk them against enemy’s ships, for there you seek an adequate gain.

The operations against Porto Rico, including San Juan, are distinctly land in character; the part of the navy is only to control the sea and cover the landing, a part minor, but indispensable, to which the battleships are not necessary. When the army approaches San Juan, it takes it in the rear where the guns of the ships are not likely to be effective. If the bombardment of the sea front is wanted, send in the monitors. They are as useless to control of the sea as any armored vessel that floats can be; and no particular harm will be done if one or more is knocked out.

The true solution of our present doubt, in my judgment, is this: either send the six armored ships together, seeing Watson through the Straits, or else postpone sending Watson and concentrate on Porto Rico. For the reasons set forth above, I do not consider our force justifies the contemplated division of it.12 However beneficial the effect upon our diplomacy to reinforce Dewey, it is by no means equal to the injury to our diplomacy caused by a couple of armored ships being disabled.13

To this I would add, that the approach of the hurricane season14 would, by itself alone, require the removal of the battleships from West India waters, which the proposed expedition to the Spanish coast insures. The whole war turns upon the efficiency of the armored fleet; upon the same, turns the negotiations for peace, and the possible interference of foreign powers.15 The Spanish navy, concentrated at Cadiz, will not, in my opinion, dare to attack six armored ships. If they fail to attack two or three, with their present force, in their own waters, they are utterly disgraced.

In order to leave no important possibility unconsidered, I mention the contingency that Spain may send some of her armored ships against our coast, or try to disturb our operations in the West Indies, during the absence of our fleet. Without denying a certain plausibility to such a move, it is to be remembered that Spain now scarcely has more than two armored vessels capable of a long voyage, viz: the Pelayo and the Carlos V.;16 that, of these two, the former carries little coal; that they dare not depart till sure that our fleet is really crossing; that our fleet will soon be on the way back; that the presence of monitors and the Texas, at Fajardo or San Juan, will protect the army base and communications; that, consequently, the breaking of the Cuban blockade, or some interruption to our coasting trade, would be the extent of the injury open to their ships before the return of our fleet would shut them up in port.

Personally, I do not believe they will venture to send important vessels so far from home, when their own coast is threatened with attack. Their best chance against us is always in the Straits of Gibralter. So evident is this, that we surely would never dream of sending our fleet there, except to help Dewey.

It is further to be considered that, if the three ships, Massachusetts, Oregon and Brooklyn, should reach Dewey without injury-which is certainly possible- the armored force left in the Atlantic viz: the Iowa, Brooklyn, Texas and New York will be less than is desirable in case of complications with a third Power,17 which is the chief reason for now reinforcing Dewey. The Brooklyn is better placed here.

A. T. Mahan

Captain, U. S. N.

Source Note: TLS, DNA, RG 45, Entry 372. The last two sentences and sign off were missing from the original text on stationery, but were taken from a copy in DNA, RG 80, Entry 194, vol. 1. An undecipherable word appeared below the address close.

Footnote 1: By the time that Mahan wrote this memorandum Spain had lost two major naval engagement at Manila Bay on 1 May, and at Santiago de Cuba on 3 July. Manila surrendered on 13 Aug. and the Santiago on 13 July. A military force under the command of Lt. Gen. Nelson A. Miles was slated to invade Puerto Rico on 25 July. See: Joint Operations at Santiago de Cuba; Blockade and Siege of Manila; and Joint Operation Puerto Rico.

Footnote 2: The combined naval and military plans originally called for the investment of San Juan de Puerto Rico and disembarkation of forces on the north coast, but Lt. Gen. Nelson A. Miles decided to land on the southern coast. See: Higginson to Sampson, 2 August 1898.

Footnote 3: RAdm. George Dewey and his Asiatic fleet were in Manila Harbor. Mahan suggested sending reinforcements to Dewey because the Spanish Ministry of Marine had ordered another fleet (under the command of RAdm. Manuel de la Cámara y Libermoore) to sail to the Philippines.

Footnote 4: A reference to the Eastern Squadron, under the command of Commo. John C. Watson, slated to sail to Spanish waters. See: The Eastern Squadron.

Footnote 5: The Straits of Gibraltar was a potential choke point for the American fleet. Only nine miles separate Europe from Africa at its narrowest point.

Footnote 6: The port of Cadiz, situated on the Atlantic Ocean, was the main base of the Spanish Navy.

Footnote 7: This naval engagement occurred off Santiago de Cuba.

Footnote 8: The core of Mahan’s naval theory was winning war thought absolute control of the sea. This concept first gained currency with the publication of The Influence of Sea Power upon History in 1890.

Footnote 9: Initially naval thinking accepted that a fortress could be destroyed by a cannonade. These tactics were used by RAdm. William T. Sampson’s fleet at San Juan de Puerto Rico, Santiago de Cuba, and elsewhere. Even old fortress walls withstood the onslaught of a naval cannonade and rarely were their guns destroyed. See: Bombardment of San Juan.

Footnote 10: RAdm. William T. Sampson bombarded the Castillo San Felipe del Morro at San Juan de Puerto Rico on 12 May, but without any appreciable damage. See: Bombardment of San Juan.

Footnote 11: The primacy of the battleship was at the core of Mahan’s strategy.

Footnote 12: Another basic Mahanian belief was that a fleet should be concentrated with as much firepower as possible.

Footnote 13: See endnote no. 11.

Footnote 14: The hurricane season begins 1 June and ends 3 November.

Footnote 15: Mahan feared that another European power, or possibly Japan, might come to the aid of Spain.

Footnote 16: Pelayo, the most powerful ship of the Spanish navy, was under the command of Capt. José Fernándiz y Niño and the flagship of RAdm. Cámara. Emperador Carlos V, the largest ship built in Spain, was under the command of Capt. José Maria Jiménez Franco and was also part of Cámara’s squadron.

Footnote 17: Most likely a reference to Germany’s seeking more territory and bases in Asia and the Pacific. The Imperial German Navy caused problems for Dewey in Manila Harbor. See: Blockade and Siege of Manila.

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