What value do the strategic theories of Alfred T. Mahan and Julian S. Corbett have in helping to make sense of contemporary threats to maritime shipping in the Red Sea?1 After all, Mahan and Corbett wrote near the turn of the 20th century in an age before missiles, drones, or even air power. However, the past remains more of a guide at the strategic level. What is occurring in the Red Sea echoes with the theories of Mahan and Corbett, especially when it relates to how they conceptualized the value of navies, the importance of sea lines of communication, and the challenges of commanding the sea. Understanding events in the Red Sea through the context of their theories allows the United States to better anticipate the possible course and outcome of naval encounters with Ansar Allah, the Yemeni militant group more commonly referred to as the Houthis.
Mahan and the Sea Lines of Communication
A career naval officer and veteran of the U.S. Civil War, Mahan rose to fame when he published The Influence of Sea Power upon History in 1890. His writings have informed generations of naval strategic thinkers. Even today, he remains a foundational source of knowledge about the strategic importance of the sea.2
Mahan explained that the sea’s “great value to mankind is that it furnishes the most copious means of communication and traffic between peoples,” and observed, “Nothing unites as does the sea; through it nations most easily communicate with one another.”3 This is especially true in the Red Sea, where approximately 12 percent of global maritime commerce must transit.
The Houthis are positioned in Yemen on the eastern side of the Bab el-Mandeb Strait. At its narrowest, it is only 14 nautical miles wide. This strait is a choke point on the maritime link between the Mediterranean and Europe on one side and Asia and east Africa on the other.
The significance of this maritime artery for commerce and oil aligns with Mahan’s following dictum: “The concrete expression of this singular importance of the sea is the merchandise in transit, the increment from which constitutes the material prosperity of nations.”4 With approximately 1 trillion dollars’ worth of maritime commerce passing through the straits each year, the economic effects of closing this strait even for a short period would be devastating. Rear Admiral Marc Miguez, the commander of Carrier Strike Group Two, admitted as much to NBC News on 5 February 2024.
Corbett and the Limits of Sea Power
A contemporary of Mahan, Corbett grew up on the other side of the Atlantic. Though he never served in the Royal Navy, he emerged in the 1890s as a naval historian, and after 1900, he became deeply emmeshed within Britain’s defense establishment. His writings sought to explain how a maritime power should most effectively act in the international environment. Though he wrote explicitly for Britain, his writings, like Mahan’s, speak broadly to the importance of navies and their use in the international environment. Even today, his masterpiece, Some Principles of Maritime Strategy, remains essential reading.5
Corbett argued that navies acting alone are limited to what they can accomplish at sea. Even with the use of land-attack missiles and aircraft, dominant navies find it extremely challenging to influence events ashore. This difficulty is apparent in the Red Sea today. Air and missile strikes have, at the time of this writing, not deterred the Houthis from attacking shipping in the Red Sea. This is unsurprising. If the Houthis consider the value of the object high enough, attacks will continue. By targeting ships in the Red Sea, the Houthis increase their credibility. Moreover, they have linked their actions to those of Israel in Gaza. As long as Israel does not back down, neither can the Houthis. Moreover, the Houthis are causing the naval powers in the Red Sea to incur far more cost than the group in Yemen appears to be spending. This seems especially true when comparing the cost ratio between U.S. and Houthi weapons. The current calculus suggests the Houthi attacks will continue unless something significant changes in the regional environment, and such changes will most likely occur on land.
This would in no way surprise Corbett. He believed that wars are won on land, not at sea. He explained, “Of late years the world has become so deeply impressed with the efficacy of sea power that we are inclined to forget how impotent it is of itself to decide a war against a great Continental state, how tedious is the pressure of naval action unless it be nicely coordinated with military and diplomatic pressure.”6 Some will certainly point out that the Houthis are not “a great Continental state.” Though true, consider the role Iran plays in that area and the effects it has on conflicts in the region. In a competition against a state like Iran, Corbett reminds us that naval power has limited utility unless it is integrated with other instruments of power.
This is not to indicate that navies lack missions. They keep the sea lines of communication open, enabling economic, diplomatic, and other instruments of power. This is where Corbett’s argument is especially important for contextualizing the situation in the Red Sea. He explains how a navy serves as the glue that binds a maritime state’s instruments of national power together. A navy provides mobility necessary for the employment of expeditionary forces; it provides presence to sustain diplomacy; and most important for the discussion here, a navy secures economic power by regulating the sea lines of communication.7
Maritime Communications and Command of the Sea
Corbett bluntly claimed, “The object of naval warfare is to control maritime communications.”8 But, how does a navy secure the sea lines of communication? Corbett described the process in terms of “command of the sea.” This is not a term that Corbett created. In fact, it was an expression common among naval strategic thinkers at the turn of the 20th century. Even Mahan used it. As Corbett grappled with the concept, he concluded that the object of the navy in war “must always be directly or indirectly either to secure the command of the sea or prevent the enemy from securing it.”9
“Command of the sea” served as Corbett’s metric to express how well a navy regulates maritime communications—precisely what the U.S. and partner navies are currently undertaking in the Red Sea. The Houthis lack the capability to secure command of the sea themselves but are attempting to do what weaker powers have sought for centuries: deny command of the sea to others who have an interest in using the sea lines of communication.
Traditionally, weaker powers at sea have sought to incur cost either by defeating their opponent’s isolated naval forces or, more often, attacking softer targets such as merchant shipping. This has historically forced stronger navies to expend disproportionate resources to protect maritime commerce.
Since the Houthis began to target commercial shipping in late 2023, the United States and other naval powers have sought to command the Red Sea. This is a chaotic environment in which the use of force has been routinely employed. Merchant ships have been repeatedly targeted. Some have been damaged and the Rubymar has even been sunk. The Houthis have also engaged the U.S. Navy. In one instance, the USS Gravely (DDG-107) was forced to destroy an incoming missile with its close-in weapon system. The risk remains high to both merchant ships and warships. The potential for catastrophic loss seems ever-present, yet this is what both Corbett and Mahan understood to reflect successful command of the sea.
Neither Mahan nor Corbett believed that command of the sea equated to absolute security for ships. It merely meant that the side that possesses command can maintain the flow of maritime commerce. Setbacks will occur. Mahan claimed, “Absolute immunity from injury, occasionally even grave, is a vain dream of those who would fain wage war without running risks. In sober conception, ‘control’ means such use of the water as a man has of a well-established business; not liable to failure, but also not exempt from reverses.”10 Corbett agreed: “We do not mean that the enemy can do nothing, but that he cannot interfere with our maritime trade and oversea operations so seriously as to affect the issue of the war, . . . . In other words, it means that the enemy can no longer attack our lines of passage and communication effectively.”11
When unpacking these quotes from both Mahan and Corbett, it is important to recognize that the world has changed in the last 100 years. Vincent Clerc, the CEO of Maersk, recently claimed, “The amount or the range of weapons that are being used for these attacks is expanding and there is no clear line of sight to when and how the international community will be able to mobilize itself and guarantee safe passage for us.” In this statement, Clerc sought a “guarantee.” This places the contemporary demand at odds with Mahan and Corbett. Both theorists recognized that the best that can be accomplished through command of the sea is to sustain the trading system, but it was impossible to avoid the risk to individual ships.
Certainly, there are significant differences between commercial shipping today and commercial shipping at the time that Mahan and Corbett wrote. The size of crude carriers and container ships has grown enormously. The value of these large ships and their cargoes dwarfs anything comparable from the turn of the 20th century. Whereas Mahan and Corbett could recognize that absolute security is an impossibility, the value of even a single large commercial ship with its cargo today forces modern audiences to grapple with the implication.
Looking Forward
Several factors make command of the sea difficult to impose and maintain. First, there is the risk to precious warships along with the expenditure of equally precious munitions. Moreover, there is the risk to maritime commerce. This is not just in terms of the ships and the cargoes themselves but the potential economic disruption stemming from shipping delays as well as increased insurance and transport costs.
Finally, and perhaps most importantly, Corbett claimed, “It may be taken as a law of maritime warfare, which cannot be omitted from strategical calculation with impunity, that every step towards gaining command of the sea tends to turn neutral sea powers into enemies.” Corbett further cautioned, “The prolonged exercise of belligerent rights, even of the most undoubted kind, produces an interference with trade that becomes more and more oppressive. But the process is usually accelerated as the sense of power inclines the dominating belligerent to push its privileges beyond admitted limits.”12 Thinking about the Red Sea today, it is important to consider what countries are willing to accept. Historically, Corbett reminds us that it is a difficult balancing act to command the sea while maintaining an international consensus to protect the free flow of commerce in a complex, often kinetic, international environment.
1. The positions expressed are mine alone and do not represent the Naval War College, the U.S. Navy, the Department of Defense, or the U.S. government, and my views are not necessarily shared by them.
2. For Mahan, see recent studies by John H. Maurer, “Alfred Thayer Mahan and the Strategy of Sea Power,” in Hal Brands, ed. The New Makers of Modern Strategy: From the Ancient World to the Digital Age (Princeton, NJ: Princeton University Press, 2023), 169–92; Nicholas A. Lambert, The Neptune Factor: Alfred Thayer Mahan and the Concept of Sea Power (Annapolis, MD: U.S. Naval Institute, 2024).
3. Alfred Thayer Mahan, Naval Strategy Compared and Contrasted with the Principles and Practice of Military Operations on Land (Boston: Little, Brown, 1911), 303; Mahan, Lowell Institute Lecture: “Naval Warfare,” circa 1897, pt. 3, Papers of Mahan, Library of Congress, Container 5, Reel 4.
4. Alfred Thayer Mahan, The Problem of Asia and Its Effect upon International Policies (London: Sampson Low, Marston, 1900), 52.
5. For Corbett, see the recent book by Andrew Lambert, The British Way of War: Julian Corbett and the Battle for National Strategy (New Haven: Yale, 2021).
6. Julian Corbett, England and the Seven Years’ War: A Study in Combined Strategy, vol. 1 and 2 (London: Longmans, Green, 1907), 1:5.
7. Corbett, England and the Seven Years’ War, 1:6; Kevin D. McCranie, Mahan, Corbett, and the Foundations of Naval Strategic Thought (Annapolis, MD: U.S. Naval Institute Press, 2021), 87–88.
8. Corbett, Some Principles of Maritime Strategy, reprint (Annapolis, MD: U.S. Naval Institute Press, 1988), 117.
9. Corbett, Some Principles, 91.
10. Alfred Thayer Mahan, “Torpedo Craft vs. Battleships,” Collier’s Weekly 33 (21 May 1904), 16.
11. Corbett, Some Principles of Maritime Strategy, 105.
12. Corbett, England and the Seven Years’ War, 2:5.
