Alfred Thayer Mahan (September 27, 1840 – December 1, 1914) was a United States naval officer and historian, whom John Keegan called "the most important American strategist of the nineteenth century." His book The Influence of Sea Power Upon History, 1660–1783 (1890) won immediate recognition, especially in Europe, and with its successor, The Influence of Sea Power Upon the French Revolution and Empire, 1793–1812 (1892), made him world-famous and perhaps the most influential American author of the nineteenth century.
Whether they will or no, Americans must now begin to look outward. The growing production of the country demands it.
The surer of himself an admiral is, the finer the tactical development of his fleet, the better his captains, the more reluctant must he necessarily be to enter into a melee with equal forces, in which all these advantages will be thrown away, chance reign supreme, and his fleet be place on terms of equality with an assemblage of ships which have never before acted together.
The history of sea power is largely, though by no means solely, a narrative of contests between nations, of mutual rivalries, of violence frequently culminating in war. The profound influence of sea commerce upon the wealth and strength of countries was clearly seen long before the true principles which governed its growth and prosperity were detected. To secure to one's own people a disproportionate share of such benefits, every effort was made to exclude others, either by the peaceful legislative methods of monopoly or prohibitory regulations, or, when these failed, by direct violence. The clash of interests, the angry feelings roused by conflicting attempts thus to appropriate the larger share, if not the whole, of the advantages of commerce, and of distant unsettled commercial regions, led to wars. On the other hand, wars arising from other causes have been greatly modified in their conduct and issue by the control of the sea. Therefore the history of sea power, while embracing in its broad sweep all that tends to make a people great upon the sea or by the sea, is largely a military history...
It is only when effort is frittered away in the feeble dissemination of the guerre-de-course, instead of being concentrated in a great combination to control the sea, that commerce-destroying justly incurs the reproach of misdirected effort. It is a fair deduction from analogy, that two contending armies might as well agree to respect each other's communications, as two belligerent states to guarantee immunity to hostile commerce.
Force is never more operative than when it is known to exist but is not brandished.