#Reviewing God and Sea Power

God and Sea Power: The Influence of Religion on Alfred Thayer Mahan. Suzanne Geissler. Annapolis, MD: United States Naval Institute Press, 2015.


Few, if any students or practitioners of strategy can argue the importance of Admiral Alfred Thayer Mahan’s influence on sea power theory, as well as his impact on the American military institution as a whole. As with any theorist, however, we tend to examine his body of work, and to look at the factors that shaped who he was as a strategist and a mariner.  Most works only give a cursory glance at the things that influenced Mahan’s character across all facets of his life. In God and Sea Power, author Suzanne Geissler goes beyond that, following the closely-interwoven relationship between Mahan’s faith and his work as a sailor, leader, and strategist.  By understanding Mahan as a Christian, we can not only see how his career, his theories, and his life developed over time, but also understand religion’s influence on one of the greatest naval minds in history.

Geissler, a professor of history at William Paterson University, is both a theologian and historian by education and profession. In God and Sea Power, she critically details the relationship between Mahan’s upbringing and the development of his faith as an adult. Describing his youth as the son of United States Military Academy professor Dennis Mahan, she tightly weaves the influence of Dennis’s Episcopal roots on not only how the Academy ran, but also in the day-to-day life of the Mahan household. Alfred’s youth was strongly shaped by religion, and two of Alfred Mahan’s greatest influences were not only his father, but also his uncle Milo, with whom he lived during his formative teenage years and while attending Columbia University. This forged a great theological mentorship between Milo and Alfred that carried on for years.

This is an opportunity to take a look at how closely intertwined religion was in all aspects of life, to include military service, in Mahan’s time. At West Point and at the United States Naval Academy, students were either required or at least strongly encouraged to attend religious services. This environment is in sharp contrast to today’s military academies. Geissler describes how at Annapolis, Mahan attended services, but frequently critiqued the chaplaincy. This was mainly because of the content of their teachings, not the requirement to attend, as his upbringing established a very strong background in scripture and teachings. Throughout his career, Mahan regularly attended worship services both while underway and in port. Moreover, his professional relationships were frequently influenced by either a mutual desire with fellow officers to grow in faith, or in Mahan’s desire to bring others to a relationship with God. In one striking example, Mahan’s insistence on bringing every instance of association with his friend Theron Woolverton to a chance to minister ultimately led to driving a wedge in their relationship. This relationship, which biographer Robert Seager criticized as being “almost unnatural,” was to Geissler just another example of Mahan’s struggle with balancing his devotion to himself, to his country and his fellow sailors, but mostly to God.

In God and Sea Power, Geissler goes to great lengths to challenge other authors critical of Mahan’s character both as an officer and as a man, and particularly calls to task Seager's 1977 biography, Alfred Thayer Mahan: The Man and His Letters, for doing just that. This work was a scathing critique of Mahan’s life, and Geissler takes umbrage with his coverage of Mahan’s life. What she sees instead, using Mahan’s own letters and journal entries as evidence, is an imperfect man who for some time struggled with the typical trappings of growing up, finding oneself, and determining what direction your life should take. To Geissler, Mahan was no different than any young man who left home, got an education, and joined the military. He struggled with the temptations of life at the academy and later at sea, often falling prey to the vices of lust and drink. She hardly sees these as the failings of a man of weak moral fiber though, but rather the normal progression of a man rekindling his faith. Soon after the Civil War, Mahan had his moment of “Crisis and Conversion,” when on a tour as executive officer of the USS Muscoota, and later as an ordnance officer at the Washington Navy Yard, he suffered from bouts of depression and crises of faith. It was at this point he sought a closer relationship with and to “draw nearer in Communion with God.” This turning point provided the religious impetus that directed his approach to duty for years.

Geissler also takes the time to reveal the link between Mahan’s religious beliefs and his most noted contributions, those as an author of sea power strategy. His greatest work, The Influence of Sea Power Upon History: 1660-1783, was released to widespread acclaim across the United States and is still regarded as perhaps the most influential single book on naval strategy ever written. His second-most celebrated text, a detailed biography of the life of Lord Nelson, was also released to widespread acclaim. Mahan, Geissler notes, saw Nelson as a man much like himself. Nelson was a devout Christian, a highly regarded sailor, and a man of high character. Nelson was also flawed, as his contributions were often clouded by a tawdry affair he had with a married woman. Despite this, both Mahan and Nelson believed the success of Britain (as Mahan believed of the United States as well) was shaped by “divine providence,” or God’s hand.

Alfred Thayer Mahan

Where religion truly took the center stage in Mahan’s life was after his retirement from the Navy in 1896. During this time, he shifted his professional focus to continuing literary pursuits, as well as engaging in foreign mission work. Christianity was interwoven throughout his books, and he often used biblical quotes to underscore points within his writing. Mahan also became heavily engaged in political and diplomatic engagement, and was even called back to service during the Philippine incursion to serve on the Navy Board. Throughout this time, his views on just war theory were shaped by his religious beliefs, almost to a point that many would believe to be counter to how a Christian would believe. Geissler states that Mahan was certainly no pacifist, however, and was often accused of being a warmonger. By using the examples of Mahan’s support of operations using “asphyxiating bombs” and his backing of hospital ships being seen as legitimate targets in warfare, she illustrates the controversy that Mahan’s influence in the U.S. and around the world as a strategist public role as a Christian, often created.

God and Sea Power is a highly-detailed yet easy to read reflection on Alfred Thayer Mahan’s growth, development, education, and maturation as a man, a sailor, a strategist, and a Christian. Like many military leaders of his time, Mahan leaned heavily on his faith in nearly every aspect of his life. Students of Mahanian naval theory might find this book lacking in its coverage of strategy, but anyone interested in Mahan’s greater influence on the military as a whole will find it a compelling account of his life from a different perspective.

Geissler’s affinity for Mahan’s character, his works, and his influence on the Navy is evident throughout the text, almost to a fault. She devotes a significant portion of the text to highlighting and subsequently countering Seager’s criticisms of Mahan, though it seldom detracts from her consideration of Mahan’s life. Geissler’s biography seamlessly weaves together Mahan’s childhood in the Episcopal environment of his father and his uncle. This backdrop set the stage for the internal struggle that so frequently plagued Mahan’s mind, yet at the same time brought him back to his faith after each stumble. By demonstrating his resilience as a flawed man of conviction, Geissler truly highlights a portion of the respected strategist’s character that few students of Mahan have covered.


Steven L. Foster is an Army Strategist currently assigned to United States Transportation Command. The views expressed in this article do not reflect the policy or position of any official organization.


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