Mahan and Trump Are Political Economists
While Alfred Thayer Mahan is often remembered for his late-19th-century advocacy of a large and powerful battle fleet, he was, above all else, a political economist. His central concern was “sea power”—the idea that seaborne commerce generates national wealth and, ultimately, national power. Mahan documented how trade created efficient markets and argued that economic vitality rested on the movement of commodities and manufactured goods carried by ships at sea. His thinking remains especially salient today, in an era of renewed great-power competition.
In his second term, President Donald J. Trump is also emerging as a political economist in a distinctly Mahanian sense. For Trump, national security is not solely a function of military capability; it is inseparable from the economic foundations that make military power possible. Economic growth underwrites research and development, sustains an industrial base, and enables military recruitment. Great-power competition thus unfolds simultaneously in military and economic domains, with national prosperity serving as both a means and an end.
Congress recognizes this linkage. In 2023, it expanded the Title 10 responsibilities of the U.S. Navy beyond an exclusive emphasis on readiness for “prompt and sustained combat operations at sea.” The statute now directs that “the Navy shall be organized, trained, and equipped for the peacetime promotion of the national security interests and prosperity of the United States and for prompt and sustained combat incident to operations at sea.” This language reflects a broader understanding of naval power as an instrument of political economy, not merely a warfighting enterprise.
The ocean is the great highway over which global trade flows, creating markets and enabling economic exchange. This commerce raises standards of living and produces wealth that can be transformed into national power. For a maritime state operating at a global scale, sea power confers a decisive advantage over land powers that can only exploit resources within their immediate hinterlands. Mahan’s thesis explains why the United States requires a global navy: to protect commercial sea power and, when necessary, to deny adversaries access to the oceanic trading system as a means of economic and military coercion.
Here lies the natural alignment between what the U.S. Navy uniquely provides and the Trump administration’s economic and strategic priorities. Yet this alignment remains largely unarticulated. Navy doctrine appears fixated on battle-force operations and war at sea as ends in themselves, without embedding those activities in a broader vision of victory, national power, and deterrence. Sea control and command of the ocean are treated as operational objectives rather than as instruments of political economy that shape outcomes short of—and during—war.
This strategic shortsightedness has historical precedent, with disastrous consequences. It plagued the Germans, Japanese, Italians, and Soviets in the twentieth century, all of whom failed to integrate naval power into a coherent theory of national power. China, by contrast, appears to have absorbed Mahan’s lessons. It is constructing a global trading infrastructure and a navy designed to protect—and leverage—that system.
Winning battles at sea is, of course, vitally important. The capability to do so remains a cornerstone of deterrence. But as Nicholas Lambert demonstrates in The Neptune Factor: Alfred Thayer Mahan and the Concept of Sea Power, a global navy provides strategic leverage far beyond tactical victory. Winning battles is a means to a greater end. As Lambert quotes Mahan:
The weaknesses of commerce—the fatally vulnerable parts of its system—are the commercial routes over which ships pass. They are the bones, the skeleton, the framework of the organism. Hold them, break them, and commerce falls with a crash, even though no ship is taken, but all locked up in safe ports… A navy so planned is for defense indeed, in the true sense that the best defense is to crush your enemy by depriving him of the use of the sea.
(Emphasis added.)
Lambert’s purposeful rendering of “$ea Power” captures Mahan’s bloody-minded clarity about the Navy’s role in American political economy. Sea power is “commercial before it is military.” It exerts strategic leverage by controlling access to the global trading system—the arteries of the world economy. Those states well supplied with the “blood” of trade prosper; those cut off from it atrophy. Mahan was explicit that the destruction or disruption of an enemy’s commerce could force capitulation without decisive fleet engagements.
It is therefore disconcerting that neither the Trump administration nor the Navy has fully articulated the Mahanian basis of their shared interests. The President supports naval expansion without explaining how a larger fleet underwrites innovation, manufacturing, and economic vitality by stabilizing global commerce. Naval leaders welcome political support for shipbuilding but remain largely silent on how naval power advances the administration’s economic agenda.
Yet the logic is clear. The Fleet enables continued commerce with allies while constraining adversaries’ access to global markets during crisis or war. The Navy’s ability to regulate the movement of resources worldwide gives the United States a form of leverage not yet matched by other great powers—and one that can be exercised short of war to signal resolve and preview the consequences of aggression. These capabilities underpin diplomacy, reinforce the Army and Air Force, and give credibility to American commitments, which remain the foundation of deterrence and security.
In peacetime, the Navy ensures that global trade remains safe and predictable. In crisis or war, it offers a dominant instrument of great-power competition: the ability to isolate an adversary from the global political economy. Mahan understood that presidents would eventually recognize commerce as the foundation of American power. President Trump appears to share that intuition. The Navy’s task now is to articulate—clearly and strategically—how it protects that economy in peace, strengthens deterrence, and generates decisive leverage in war. Not independent of other instruments of power, but central and indispensable to them all.
CDR Giarra is a retired Navy pilot and Navy designated strategic planner. He is the President of Global Strategies & Transformation.
Dr. Wirtz is a professor at the U.S. Naval Postgraduate School.
The opinions expressed here are those of the authors alone and do not represent the position of any government, government agency, commercial firm, or other organization.