Geostrategic Media Political Commentary, Analysis, Security, Defense
James Holmes
In the late 1890s, naval theorist Alfred Thayer Mahan made a compelling argument for the United States’ possession of Hawaii. Those interested in the annexation of Greenland might take note.
Once upon a time, an eminent American full-throatedly espoused annexing a strategically situated, lightly populated island territory—and deployed a host of reasons for why the land grab was necessary.
I refer, of course, to US Navy captain and historian Alfred Thayer Mahan’s advocacy of annexing the Hawaiian Islands, alternatively known as the Sandwich Islands in those days. Mahan was writing during the 1890s, the heyday of empire. The strategist framed his brief for annexation in a letter to the editor of the New York Times (1893), from which he later derived a full-blown Forum article titled “Hawaii and Our Future Sea Power” (1897).
Circumstances prompted Mahan to take up his pen in both instances. In 1893, annexationists were clamoring for Democratic president Grover Cleveland to lay claim to the archipelago. Why that year in particular? Because opportunity beckoned. Propertied American “sugar barons” who dominated the islands had ousted Queen Liluokalani’s indigenous regime with support from a US Navy cruiser, USS Boston. The American minister to Hawaii—the United States only instituted the rank of ambassador that year—swiftly recognized the revolutionary government as the lawful authority in the islands.
For Mahan, revolutionary upheaval in the Hawaiian archipelago meant a chance to act boldly. So he wrote. Yet President Cleveland quashed the annexation treaty. Momentum toward annexation stalled, before building up again in 1897 under the presidency of Republican William McKinley. So Mahan wrote again that year. Not until 1898, in the closing days of the martial spasm known as the Spanish-American War, did Washington make the annexation of Hawaii formal.
The maritime historian’s letter to the editor and article sound at once ripped from the headlines and jarringly out of step with modern realities. That makes them an ideal starting point for evaluating President Donald Trump’s vow to purchase Greenland from Denmark, a stalwart NATO ally, or to seize this prime northerly real estate by force should its inhabitants or the Danish government balk at his entreaties.
Why Did America Need Hawaii?
Mahan proclaimed that the United States had a surpassing national interest in the Hawaiian Islands, grounded in commercial, diplomatic, and military imperatives in the Pacific Ocean. After all, an entirely new sea lane of world-historical consequence was in the making. Before long, that is, a transoceanic canal would cross the Central American isthmus at either Panama or Nicaragua. (Nicaragua was the frontrunner when Mahan wrote. Panama ended up being the site, and the canal opened for seaborne transit in 1914.) Mahan declared that the new nautical shortcut would constitute the United States’ “gateway” to the Pacific, sparing commercial and naval shipping the long, burdensome, cost-intensive voyage around Cape Horn. To safeguard the new maritime thoroughfare, Mahan demanded that the US Navy position itself to command the approaches to the isthmus on both its Caribbean Sea and Eastern Pacific sides.
If Mahan obsessed over the Caribbean and Pacific, Trump is today preoccupied with the Arctic Ocean. The Arctic is a semi-enclosed body of water akin to the combined Caribbean and Gulf in many ways, but it is also a “new” and unique theater for commercial and strategic endeavor. The planet is gradually warming, opening waters to shipping formerly barred by ice for part of the year. The Arctic promises to be a fascinating, shapeshifting theater unlike any other. That’s because navigable routes will shift with the seasons as the ice melts and refreezes. And presumably the shifts will be hard to predict from year to year. Geography—the physical setting for strategic competition—promises to be dynamic rather than static in Arctic climes. This stands in contrast to warmer semi-enclosed seaways such as the Caribbean, Mediterranean Sea, or South China Sea. No problems with icebergs in these temperate expanses.
Arctic antagonists will shift their operational patterns as the polar theater’s geophysical conformation morphs. Trump is trying to get ahead of new realities in northerly seas.
Both the likenesses and stark disparities between then and now make reviewing Mahan’s rationale for claiming Hawaii worthwhile. The historian saw a decision of utmost gravity looming in the 1890s: “the United States finds herself compelled to answer a question—to make a decision—not unlike and not less momentous” than the Roman Senate’s debate (264 B.C.) whether to “occupy Messina, and so to abandon the hitherto traditional policy which had confined the expansion of Rome to the Italian peninsula.” Rome had to decide whether to expand beyond continental Europe; the Senate ultimately decided Yes, with fateful consequences in the form of wars against rival Carthage. The United States had to decide whether to expand beyond North America in search of commercial, diplomatic, and naval clout.
By conjuring ancient Rome, Mahan implied the answer, likewise, was Yes.
How Hawaii and Greenland Are Different
Now, a couple of disparities between the Hawaii debate in the 1890s and Greenland in our time come instantly to mind. First, no revolution in Greenland, US-instigated or not, has overthrown the established authorities on the island. No equivalents to the American sugar barons are poised to topple Greenland’s government from within. There is little place for Mahanian political opportunism in Greenland. Indeed, the leaderships of Greenland and its parent state, Denmark, remain in power—and are staunchly opposed to a transfer of sovereignty to the United States. Nor are these neutrals, like Hawaii in the days of Mahan; nor are they hostile. In fact, Trump envisions wresting territory from Denmark, a charter NATO ally. Doing so would set a dangerous precedent for the United States, which has no strategic position beyond its immediate neighborhood without allies. The White House should think twice before forfeiting America’s good name as an ally of choice.
And second, like Rome of antiquity, America was mulling whether to push outward during the lifetime of Mahan. Americans of a geopolitical bent, who traditionally looked toward Europe for cultural and historical reasons, turned their gaze southward toward the Gulf of Mexico and Caribbean Sea, where the transoceanic canal was starting to become a reality, and ultimately westward toward the Pacific. They decided to expand.
By contrast, today’s United States, a power of global scope since at least 1945, is refocusing its attention and energies homeward and northward. The United States is not withdrawing from forward deployments elsewhere in the world, in particular from the rimlands of the Indo-Pacific and Western Europe, judging from the Trump administration’s 2025 National Security Strategy. That said, the National Security Strategy explicitly elevates the Western Hemisphere to tops among Washington’s strategic priorities. In turn, it demotes other theaters on America’s list of priorities. To some degree, then, Trump’s global America is looking inward, whereas Mahan’s regional America was looking outward.
Admittedly, annexing Greenland would swivel the United States’ strategic axis toward the Arctic Ocean. In that sense the republic would be pushing out into the world once again, aiming its efforts toward a different point of the compass. But again, such an acquisition would be chiefly about defending US prerogatives in the Western Hemisphere, in this case by obtaining real estate fronting on polar waters. Such an acquisition would project US territory to the fringes of the Arctic, North America’s northern frontier, where Russia and China delight in making mischief at sea. This is also a battlespace through which Russia might aim missile attacks at the homeland, making Greenland an auspicious site for missile defenses. Trump is not wrong about its strategic importance.
And if annexation goes forward? Presumably US air and ground forces forward-stationed there would defend the island, augmented by maritime forces sweeping around the Atlantic coast of Canada from Newport, Norfolk, and Mayport. Greenland would also be an obvious home for some of the new icebreakers the US Coast Guard intends to procure. The Arctic Ocean will be a law-enforcement and lifesaving as well as military theater, and thus a Coast Guard preserve.
Hawaii’s Geography Was Ideal for US Pacific Projection
Back to the age of Mahan. The historian cited offensive and defensive motives for claiming the Hawaiian Islands. On the forceful side, the archipelago would project US commercial and naval prowess toward China and Japan. Seagoing commerce was king for Mahan. Manufacturing, transporting, and selling goods was how an industrial republic like the United States enriched itself, and paid for a great navy to protect the merchant fleet and undertake geopolitical missions ordained by the leadership in Washington. Geography played an inordinate part in the Mahanian scheme. He pointed out that the most convenient sea routes from the canal to East Asia would run close to Hawaii, making the archipelago an ideal way station to support the voyages of steam-driven, coal-hungry merchantmen and warships.
And it was the only waystation available in the Eastern Pacific. Mahan regarded “situation,” meaning geographic position, “strength,” and “resources” as the three key metrics for judging the value of a candidate for a maritime outpost. Hawaii abounded in strategic position, by far the most important of Mahan’s metrics. If the open sea equates to a featureless plain, the islands were ideally suited to dominate an empty plain approximately 2,100 nautical miles in diameter. There was no alternative to Honolulu as a harbor between the isthmus and East Asia. Moreover, the Hawaiian Islands lay astride the sea lanes leading from British Columbia to New Zealand and Australia. British ships would have to call at Honolulu as well.
Strength and resources, Mahan’s other two factors, could be improved through deliberate policy. Pearl Harbor could be fortified for defense, bolstering its strength against seaborne attack. Resources could be supplied to support visiting ships.
What If an Adversary Nation Owned Hawaii Instead?
On the defensive side, Mahan saw peril in letting a potentially hostile maritime power ensconce itself in Hawaii. In his 1893 New York Times letter he fretted that imperial China might “burst her barriers,” surging outward beyond its frontiers to the west or east. The great armies of Europe interposed a bulwark against eastward expansion across Eurasia, but China might just as easily cast its eyes “toward the Pacific.” Therein lay danger for the United States. The Celestial Empire could entrench itself in Hawaii by virtue of preponderant demographics. Mahan observed that Chinese labor already made up a major share of the islanders relative to the small indigenous Polynesian populace. Numbers carried political and strategic weight.
Of course, the hypothetical Chinese threat had mostly lapsed by 1897, when Mahan wrote “Hawaii and Our Future Sea Power.” At that time, China had recently suffered a stinging naval defeat in the Yellow Sea at the hands of the upstart Imperial Japanese Navy. So Mahan turned his attention to the potential menace posed by Great Britain and its Royal Navy, the world’s supreme marine fighting force. He professed that there was no reason for the United States and Britain to be at odds in the Pacific. But at the same time he pointed out that the Hawaiian Islands overshadow the entire US West Coast, lying no more than 2,500 nautical miles from any point from the Mexican to the Canadian borders, including major bases in San Diego, San Francisco, and the Puget Sound. Hedging against a hostile offshore naval station represented sound strategy for Mahan, lest a downturn in relations drive the English-speaking powers to blows.
Now, there is a bit of an everything-but-the-kitchen-sink feel to Mahan’s advocacy. He knew he needed to appeal to many segments of American society to exert influence on US policy and strategy. And so he tosses in any argument likely to resonate with fin de siècle audiences able to shape US policy and strategy toward the sea. For instance, he broaches a point evidently rooted in Social Darwinism: “the conditions of the world being what they are, if we do not advance we recede.” The conceit being that societies are like organisms. They grow and thrive or they wither and die. He makes the case, familiar at the time, that America was fated to spread westward.
There were barriers in every other direction. Great Britain operated a “chain” of naval bases in the Atlantic, ranging from Halifax to Bermuda to Santa Lucia to Jamaica. These fettered US options in the Atlantic and Caribbean—warranting action in the Caribbean, the Central American isthmus, and the Eastern Pacific to secure the US position. If the United States could not expand eastward owing to the Royal Navy; northward because of Canada, then part of the British Empire; or across the land bridge into Latin America, there was only one direction left: westward into the Pacific.
Mahan invoked “spheres of interest” thinking, noting that “certain defined spheres of influence, for our own country and for others, [have] been reached already between Great Britain, Germany, and Holland in the Southwestern Pacific.” A Pacific condominium of Western powers was already in place to the distant west and south. Closer to home, the United States needed to assert a nautical preserve in the Eastern Pacific centered on the Hawaiian archipelago. Mahan cited differentials of power along the Pacific coasts of North, Central, and South America: “The United States is by far the greatest, in numbers, interests, and power, of the communities bordering upon the eastern shores of the North Pacific.” By implication, the United States’ claims should outweigh those of other American states. For example, there were 65 million Americans in 1897, compared to 6 million Canadians. With a demographic advantage exceeding 10:1, Mahan insisted that US interests in Hawaii came first.
Mahan and Manifest Destiny
Lastly, and most powerfully for the time, came Mahan’s argument from Providence. He did not use the phrase Manifest Destiny, but the ideas shone through. Expansion should be the rule from henceforth: “the annexation. . .of Hawaii would be no mere sporadic effort, irrational because disconnected from an adequate motive, but a first-fruit and a token that the nation in its evolution has aroused itself to the necessity of carrying its life—that has been the happiness of those under its influence—beyond the borders which heretofore have sufficed for its activities.” Manifest Destiny was not just about subduing a continent, as the United States had done by 1890, when the census declared the western frontier closed. It was about dedicating the republic to further expansion across the seas. Here Mahan tied his Social Darwinist theme to religion: “Comparative religion teaches that creeds which reject missionary enterprise are foredoomed to decay. May it not be so with nations?”
In other words, missionary zeal underwrote national vigor. Mahan, the foremost navalist of the age, closed by reminding readers that all of this depended on building and maintaining a locally supreme US Navy. Bases were worth little without a navy able to command the maritime commons around them. That sounded warlike, but it need not mean running an open-ended naval arms race. The US Navy could get by with less. European powers had commitments elsewhere on the globe, not to mention conflicts among themselves in Europe. These factors limited how much force they could commit to the Pacific. The fraction rival European navies were likely to commit to Pacific contingencies constituted the benchmark of adequacy for the US Navy in vital expanses—including Hawaii and its environs. The US Navy could remain globally inferior while making itself locally superior.
And that was precisely what fleet designers should do long as US commercial, diplomatic, and military goals remained confined to key subregions of the Western Hemisphere. Enough was enough. Excess was waste.
So there’s your gamut of Mahanian determinants for gauging the Trump administration’s bid for Greenland: geopolitical, commercial, diplomatic, military, offensive, defensive, cultural, providential. Ponder—and judge for yourself.
About the Author: James Holmes
James Holmes is J. C. Wylie Chair of Maritime Strategy at the Naval War College, a Distinguished Fellow at the Brute Krulak Center for Innovation & Future Warfare, and a Faculty Fellow at the University of Georgia School of Public and International Affairs. A former U.S. Navy surface-warfare officer and combat veteran of the first Gulf War, he served as a weapons and engineering officer in the battleship Wisconsin, engineering and firefighting instructor at the Surface Warfare Officers School Command, and military professor of strategy at the Naval War College. He holds a PhD in international affairs from the Fletcher School of Law and Diplomacy at Tufts University and MAs in mathematics and international relations from Providence College and Salve Regina University. The views voiced here are his alone.
