Strategic Considerations of Naval Communications

This is one of Mahan’s best passages on the strategy of naval warfare.

Continuing Farragut Captures New Orleans,
our selection from Admiral Farragut by Alfred Thayer Mahan published in 1892. The selection is presented in thirteen easy 5 minute installments. For works benefiting from the latest research see the “More information” section at the bottom of these pages.

Previously in Farragut Captures New Orleans.

Time: April 25 to May 1, 1862
Place: Mouth of the Mississippi River

It is commonly true that in the effort to cut the communications of an opponent one runs the risk of exposing his own; but in this case the attacking force was one pre-eminently qualified to control the one great medium of communication throughout that region — that is, the water. Also, although in surrendering the river Farragut gave up the great line of travel, he kept in view that the bayou system offered an alternative, doubtless greatly inferior, but which, nevertheless, would serve to plant above the forts, under the protection of the navy, such troops as should be deemed necessary; and that the combined efforts of army and navy could then maintain a sufficient flow of supplies until the forts fell from isolation. Finally, a fleet is not so much an army as a collection of floating fortresses, garrisoned, provisioned, and mobile. It carries its communications in its hulls and is not in such daily dependence upon external sources as is the sister service.

In deciding, therefore, against awaiting the reduction of the forts by direct attack, and in favor of attempting the same result by striking at the interests they defended and the base on which they rested, Farragut was guided by a calculation of the comparative material risks and advantages of the two courses, and not mainly by consideration of the moral effect produced upon the defenders by a successful stroke, as has been surmised by Lord Wolseley. This eminent English authority attributes the success of the expedition against New Orleans to three causes.

First, the inadequate previous preparation of the naval part of the New Orleans defenses; second, the want of harmonious working between the Confederate naval and military forces; and, lastly, Farragut’s clear appreciation of the moral effect he would produce by forcing his way past the defenses of Fort Jackson and Fort St. Philip, and by his appearance before New Orleans. For, after all, the forts were never captured by actual attack…. This brilliant result is a striking instance of the due appreciation by a commander of the effect which daring achievements exert on men’s minds, although, as in this case, those daring acts do not actually, directly, or materially make certain the end or surrender they may have secured.”

And, again, in another place:

Admiral Farragut’s success was mainly due to the moral effect produced by his gallant passage of the forts…. He never reduced the forts, and seems to have done them but little harm.” [1]

[1: Lord Wolseley in North American Review, vol. cxlix, pp. 32-34, 597. The italics are the author’s.]

The moral effect produced in war upon men’s minds, and through the mind upon their actions, is undeniable, and may rightly count for much in the calculations of a commander; but when it becomes the sole, or even the chief reliance, as in Bonaparte’s advance into Carinthia in 1797, the spirit displayed approaches closely to that of the gambler who counts upon a successful bluff to disconcert his opponent. The serious objection to relying upon moral effect alone to overcome resistance is that moral forces do not admit of as close knowledge and measurement as do material conditions. The insight and moral strength of the enemy may be greater than you have means of knowing, and to assume that they are less is to fall into the dangerous error of despising your enemy. To attribute to so dubious a hope, alone, the daring act of Admiral Farragut in passing the forts and encountering the imperfectly known dangers above, is really to detract from his fame as a capable as well as gallant leader. That there were risks and accidents to be met he knew full well; that he might incur disaster he realized; that the dangers above and the power of the enemy’s vessels might exceed his expectations was possible; war can not be stripped of hazard, and the anxiety of the doubtful issue is the penalty the chieftain pays for his position. But Farragut was convinced by experience and reflection that his fleet could force its passage; and he saw that once above the material probabilities were that army and navy could be combined in such a position of vantage as would isolate the forts from all relief, and so “actually, directly, and materially make certain their surrender,” and secure his end of controlling the lower Mississippi. There was only one road practicable to ships to pass above, and that led openly and directly under the fire of the forts; but having passed this, they were planted across the communications as squarely as if they had made a circuit of hundreds of miles, with all the secrecy of Bonaparte in 1800 and in 1805. Are strongholds never “captured” unless by “actual attack”? Did Ulm and Mantua yield to blows or to isolation?

Such, certainly, was the opinion of the able officers who conducted the Confederate defense, and whose conduct, except in matters of detail, was approved by the searching court of inquiry that passed upon it. “In my judgment,” testified General M. L. Smith, who commanded the interior line of works and was in no way responsible for the fall of Forts St. Philip and Jackson, “the forts were impregnable so long as they were in free and open communication with the city. This communication was not endangered while the obstruction existed. The conclusion, then, is briefly this: While the obstruction existed, the city was safe; when it was swept away, as the defenses then existed, it was in the enemy’s power.” [2] General Lovell, the commander-in-chief of the military department, stated that he had made preparations to evacuate New Orleans in case the fleet passed the fort by sending out of the city several hundred thousand rations and securing transport steamers.

[2: Official Records of the War of the Rebellion. Series I, vol. vi, p. 583.]

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