Trump’s claim that the U.S. has a vital interest in Panama and its canal harks back to the early exponents of American great power competition. The canal was seen as the keystone of American empire and the greatest security for American dominance in the Western hemisphere. Alfred Thayer Mahan, the great American naval theorist, wrote in 1897,
the Isthmus, with all that depends upon it,—its canal and its approaches on either hand,—will link the eastern side of the American continent to the western as no network of land communications ever can. In it the United States has asserted a special interest. In the present she can maintain her claim, and in the future perform her duty, only by the creation of that sea power upon which predominance in the Caribbean must ever depend.
Theodore Roosevelt, speaking under the sway of Mahan’s monumental work The Influence of Sea Power Upon History, declared that his own expansive vision for the United States rested upon the completion of an isthmian canal connecting the two great oceans bordering the United States: “If we are to hold our own in the struggle for naval and commercial supremacy, we must build up our power without our borders. We must build the Isthmian canal, and we must grasp the points of vantage which will enable us to have our say in deciding the destiny of the oceans of the east and west.”
Mahan and Roosevelt presciently considered the destiny of the ascendant United States to be dominance through naval and commercial power, and considered control of the future interocean route to be of utmost importance. A canal would enable the rapid expansion of American trade and influence in Asia (to the detriment of competing naval power Great Britain), funnel great amounts of trade from other countries through the regional waters of the United States, and enable the rapid transit of American naval assets between oceans. Such a situation would also compel the country to establish the regional influence and naval power necessary to secure its interests and defend its hold over the route.
To secure that advantage, the U.S., principally under the leadership of president Theodore Roosevelt, expended no small amount of blood and treasure. Between 1903 and 1914, the country spent over $375 million (about $12 billion in 2024 dollars) to obtain and construct the canal. Nearly 6,000 people died during the American portion of its construction, most from disease and the influence of the climate. When the canal opened, it was the largest construction project in the world.