Short note on Mahan’s thoughts on naval preponderance.
Mahan surprisingly wrote a bit on naval diplomacy though he didn’t actually call it such; it was something that academics would later describe. Most of his thoughts on naval diplomacy are not found in his famous work, The Influence of Sea Power upon History. Instead, it is found in a collection of his stand-alone articles in various periodicals which have been compiled under the title The Interest of America in Sea Power.
Though Mahan tends to be associated with the idea of the “big fleet battle” and the six conditions for sea power, he also thought about how navies could be used to project political power (well, in this case, American power). However, his prescription for “naval preponderance” tends to be overshadowed by his geopolitical thinking. To extract a sliver of Mahan’s thoughts on “showing the flag”—an idea often credited to him (see here and here)—requires careful scouring of his article titled “The Isthmus and Sea Power”.
As the United States was in the process of building the Panama Canal, he pondered on the strategic importance of Panama (Mahan would refer to this as the “Isthmus”):
The conquest of Peru, and the gradual extension of Spanish domination and settlements in Central America and along the shores of the Pacific, soon bestowed upon the Isthmus an importance, vividly suggestive of its rise into political prominence consequent upon the acquisition of California by the United States, and upon the spread of the latter along the Pacific coast. The length and severity of the voyage round Cape Horn, then as now, impelled men to desire some shorter and less arduous route; and, inconvenient as the land transport with its repeated lading and unlading was, it presented before the days of steam the better alternative, as to some extent it still does. So the Isthmus and its adjoining regions became a great centre of commerce, a point where many highways converged and whence they parted; where the East and the West met in intercourse, sometimes friendly, more often hostile. (Mahan, The Isthmus and Sea Power, 1898)
History, according to Mahan, had shown that nations had fought over the Isthmus primarily for commercial purposes. And where commerce may be, there would be efforts to protect the flow of goods. It would then be necessary for nations to sustain presence (or in his words, “preponderance”) in the vicinity of the Isthmus to maintain control.
Mahan advocated the U.S. to secure its position in the Isthmus. He was sceptical of the willingness of great powers to keep the peace, especially when something as valuable as the Panama Canal was involved. His scepticism is worth quoting at length:
There is one opinion—which it is needless to say the writer does not share—that, because many years have gone by without armed collision with a great power, the teaching of the past is that none such can occur; and that, in fact, the weaker we are in organized military strength, the more easy it is for our opponents to yield our points. Closely associated with this view is the obstinate rejection of any political action which involves implicitly the projection of our physical power, if needed, beyond the waters that gird our shores. Because our reasonable, natural—it might almost be called moral—claim to preponderant influence at the Isthmus heretofore has compelled respect, though reluctantly conceded, it is assumed that no circumstances can give rise to a persistent denial of it. […] …we cannot safely anticipate for the future the cheap acquiescence which, under very different circumstances, has been yielded in the past to our demands. Already it is notorious that European powers are betraying symptoms of increased sensitiveness as to the value of Caribbean positions, and are strengthening their grip upon those they now hold. (Mahan, 1898)
Instead of wishful thinking, Mahan argued for a more realistic approach: it was necessary for the U.S. to have a dedicated “frontline navy” (see Russell, 2006 [paywall]) in order to protect its commercial interests. The navy would essentially serve as a deterrent by maintaining presence and control of the sea in strategic positions along and around the Isthmus. As he wrote,
…we must gird ourselves to admit that freedom of interoceanic transit depends upon predominance in a maritime region —the Caribbean Sea—through which pass all the approaches to the Isthmus. Control of a maritime region is insured primarily by a navy; secondarily, by positions, suitably chosen and spaced one from the other, upon which as bases the navy rests, and from which it can exert its strength. (Mahan 1898)
Mahan closes his essay by prophesying that the U.S. would be “entangled in the affairs of the great family of nations, and shall have to accept the attendant burdens.” Therefore, having a great navy is essential as it would not just serve the short-term interest, but also the long term.
After reading this, it is unlikely that Mahan could be classified as a “thinker” of naval diplomacy, especially along the likes of James Cable, Ken Booth, or Edward Luttwak, who both proposed more robust models of naval diplomacy. However, Mahan’s prescription for naval preponderance continues to occupy the ranks of the classics of strategic thought.