The Neptune Factor

Alfred Thayer Mahan and the Concept of Sea Power

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The Neptune Factor is the biography of an idea—the concept of “Sea Power,” a term first coined by Capt. A.T. Mahan and the core thread of his life’s work. His central argument was that the outcome of rivalries on the seas have decisively shaped the course of modern history. Although Mahan’s scholarship has long been seen as foundational to all systematic study of naval power, The Neptune Factor is the first attempt to explain how Mahan’s definition of sea power shifted over time.

Far from presenting sea power in terms of combat, as often thought, Mahan conceptualized it in terms of economics. Proceeding from the conviction that international trade carried across the world’s oceans was the single greatest driver of national wealth (and thus power) in history, Mahan explained sea power in terms of regulating access to ‘the common’ and influencing the flows of trans-oceanic trade.  A nation possessing sea power could not only safeguard its own trade and that of its allies, but might also endeavor to deny access to the common to its enemies and competitors.

A pioneering student of what is now referred to as the first era of globalization, lasting from the late nineteenth century until the First World War, Mahan also identified the growing dependence of national economies upon uninterrupted access to an interconnected global trading system. Put simply, access to ‘the common’ was essential to the economic and political stability of advanced societies. This growing dependence, Mahan thought, increased rather than decreased the potency of sea power.

Understanding the critical relationship between navies and international economics is not the only reason why Mahan’s ideas remain—or rather have once again become—so important. He wrote in, and of, a multi-polar world, when the reigning hegemon faced new challengers, and confusion and uncertainty reigned as the result of rapid technological change and profound social upheaval. Mahan believed that the U.S. Navy owed the American people a compelling explanation of why it deserved their support—and their money. His extensive, deeply informed, and highly sophisticated body of work on sea power constituted his attempt to supply such an explanation.   Mahan remains as relevant—and needed—today as he was more than a century ago.

About the Author

Editorial Reviews

"Reports from various think tanks, other organizations, and media have warned of a maritime crisis for years. Their voices echo that of the patron saint of modern navalists, Alfred Thayer Mahan. In this environment, a timely new book revisits a century-old topic, enlightens readers with previously undiscovered research, and corrects misinterpretations. In reading the entirety of Mahan’s published works and discovering previously buried correspondence, Lambert resurrects the first American navalist in a way that challenges those who venerate him. This extraordinarily well-researched book outlines the need for a properly sized navy to support national goals and economic stability."—The National Interest
“Often quoted but seldom read, Alfred Thayer Mahan is sometimes dismissed as little more than a pedantic and parochial advocate of big fleets and decisive naval battles. In this brilliant new intellectual biography, Nicholas Lambert demonstrates, to the contrary, that Mahan was actually a profound analyst of the strategic implications of globalization. Original, provocative, and compelling, Lambert’s book traces the evolution of Mahan’s thought and demonstrates its contemporary relevance.  Essential reading for scholars, strategists, and naval officers alike.”—Prof. Aaron L. Friedberg, Princeton University. Author of Getting China Wrong and A Contest for Supremacy: China, America, and the Struggle for Mastery in Asia
"Although the title suggests a rather narrowly focused account, The Neptune Factor is a far-reaching reappraisal of Mahan and his interpreters from the 1890s to the present. Lambert’s insightful and readable book places Mahan’s work firmly within the context of his times. In the course of so doing the author explodes a number of widely accepted Mahan myths and shows the origins and processes of the American naval revival and subsequent rise to world power status to have been far more nuanced and complicated than suggested by earlier authors. Both historians and warfighters should benefit by reading this provocative book."—Prof. Ronald H. Spector (Emeritus), author of Professors of War and Eagle Against the Sun
"This book is essential reading for all serious students of naval history and contemporary geopolitics. Nick Lambert’s discovery of important new archival sources and a careful reconsideration of Mahan’s well-known published writing, has enabled him to produce a transformative study of Captain Alfred Mahan’s signature idea—namely the concept of Sea Power. He shows that Mahan, far from being a simplistic advocate of decisive battle, had a sophisticated understanding of the connections between naval force and international economics. Lambert’s revelations will go far to restore Mahan’s stature as the premier thinker on the role of navies in world affairs."—Prof. Jon T. Sumida (Emeritus), author of Inventing Grand Strategy and Teaching Command: The Classic Works of Alfred Thayer Mahan Reconsidered  
"Lambert's method, as in all his work, is not to proceed from received wisdom about his subject, but to go back to the original sources. The result is a book that explains – far better than any account of Mahan known to me – why he is still read in Beijing today, and why he would repay closer reading in Washington. Lambert’s Mahan is not the crude evangelist of decisive battle between battleships he is often caricatured as but a subtle and evolving thinker about the relationship between naval and economic power.  Rejecting the notion that Mahan should be read for his contributions to some abstract naval theory, Lambert insists on the need to put him in his historical context — which was dominated by massive economic change. Manifestly, Lambert’s Mahan-in-full is more relevant to contemporary US national-security policy than the legendary Mahan obsessed with “kinetic” combat operations. No less important is Lambert’s inspiration to young students of power today. His unequalled treatment of Mahan demonstrates many truths between the lines, and they resonate. As a historian, Lambert does not say what U.S. strategy should be. But The Neptune Factor offers ample food for thought for those who want American naval power to fulfill its true purpose – protecting and advancing the naturally unstable sovereignty of democracy, for both ourselves and those willing to partner in the effort."—Defense and Aerospace Report
"Your book is very important."—Cavas Ships Podcast
The Neptune Factor is a rigorous and scholarly reassessment of Alfred Thayer Mahan’s work that challenges conventional interpretations and highlights the complexity of historical strategic thought. While the book may be, at times, too dense for casual readers, its insightful analysis is essential to understanding naval power’s role in global economics and strategic planning. Lambert’s work is a valuable resource for scholars and strategists, offering a deeper understanding of sea power’s historical and ongoing impact on international relations."—National Security Institute