On the night of 2 December 1944, Commander John C. Zahm took three destroyers of Destroyer Division 120 into Ormoc Bay, on the northwestern edge of Leyte Island in the Philippines. The invasion the previous October had triggered an attritional struggle, and the Japanese were reinforcing their garrison through a town at the bay’s northern end, Ormoc. Zahm’s sweep was an attempt to gain sea control, to make further reinforcement of Leyte prohibitively costly.
Zahm did not have it easy. Japanese planes attacked his flagship, the USS Allen M. Sumner (DD-692), during the approach, and for the next two and a half hours, he was in a running battle. The frequency and unpredictable timing of the aerial attacks overwhelmed combat information center personnel and their communication circuits, keeping Zahm from developing a clear picture. A radar-equipped patrol bomber sent ahead to prowl the bay reported it empty, so Zahm pressed ahead. Once inside the bay he encountered the convoy, escorted by two small Japanese destroyers.
The bay erupted as ships of both sides and Japanese shore batteries opened fire. Zahm’s three ships sank one enemy destroyer, but the other hit the USS Cooper (DD-695) with a torpedo. Her hull broken, the Cooper sank in less than three minutes. Zahm withdrew to clarify the situation and only belatedly realized one of his ships was gone. The Japanese suffered loss but succeeded in their resupply mission. Organized resistance on Leyte would not end for another three weeks.1
The Importance of Sea Control and Command of the Sea
Zahm’s battle in Ormoc Bay highlights the importance of sea control, which Julian Corbett defined as the ability to “control the maritime communications of all parties concerned.”2 Although the Battle of Leyte Gulf had been a major victory, success in the ground campaign required cutting the island off from reinforcement. Similar struggles had been waged before, off Guadalcanal in 1942 and during the advance up the Solomons in 1943. In the Pacific, success on land was guaranteed by sea control, and this had to be earned by seeking out and destroying Japanese ships and convoys.
The situation today feels very different. More than ten years ago, retired Navy Captain Robert C. Rubel observed that the U.S. Navy had “enjoyed total command of the sea” for two decades. Lengthy dominance had bred complacency, and, according to Rubel, the Navy had “stopped talking about sea control” and even forgotten “how to.”3 Command of the sea and sea control are linked. The former involves a “strength relationship in which the weaker navy elects not to directly contest the stronger.”4 It is fundamentally about deterrence, in both peace and war. When deterrence fails, navies fight to achieve sea control and gain a position of strength from which they can maintain command of the sea. Unfortunately, Rubel’s diagnosis remains salient. Sea control appears largely irrelevant. Command of the sea is taken for granted. This is a grave miscalculation.
The nation’s Sea Services must embrace the importance of sea control and command of the sea to reach their full potential. The two concepts operate on several levels, each entwined with the national objectives of the United States and its allies. First, command of the sea is real and tangible. It delivers measurable benefit by underpinning the economic prosperity created by the global trade network. Second, command of the sea is a valuable conceptual frame. It provides a way of understanding great power competition and an effective tool for crafting national strategy. Third, command of the sea is an ideal that reflects core U.S. values. Usually these are described as a commitment to a liberal, international rules-based order, but arguably command of the sea even bolsters the U.S. commitment to liberal, representative democracy. Together, these concepts create a potent mix that argues for positioning sea control and command of the sea at the forefront of the Navy’s thinking and strategic planning.
Command of the Sea Confers Global Power
With his classic work The Influence of Sea Power Upon History: 1660–1783, Alfred Thayer Mahan argued that global power derived from command of the sea. Mahan used the rise of Great Britain as a case study and linked its emergence as a great power to the Royal Navy’s ability to achieve sea control and exercise command of the sea. Others have followed Mahan’s lead and expanded on this concept to demonstrate that navies are “essential components of the modern global political system,” and that only those powers with “superior navies” have been able to claim a position of “world leadership.”5
These arguments flow naturally from an analysis of history and geography. The oceans are the “high ground of the global system,” and the ability to control them confers unparalleled advantage. Command of the sea allows a nation’s ships, goods, commerce, and military forces to move around the globe at will. Without the ability to fight for sea control, nations are relegated to “a passive role” and become “consumers” of the global order rather than drivers of it.
The Royal Navy demonstrated this during World War I. Despite the German investment in a Risikoflotte (risk fleet) that was expected to be a credible deterrent, at the outset of the war, the Royal Navy and its allies blockaded the German Navy in its ports, swept German commerce from the seas, and isolated and captured German colonies. Great Britain was then free to use the sea to bring to bear the resources of its vast empire. The Indian Army fought in Europe, Africa, and the Middle East. On the Western Front, soldiers from Canada, Australia, and New Zealand played a vital role in defeating German forces in the campaigns of 1918. Without the Royal Navy’s command of the sea, it would have been impossible to employ these forces.
By 1918, U.S forces were fighting in Europe as well, demonstrating another truth about global power. Command of the sea enables coalition warfare; those who have it are better able to “organize and lead coalitions” against their enemies. Together, the U.S. Navy, Royal Navy, and other Allied navies overcame the U-boat threat, ensured Britain’s survival, and delivered the American Expeditionary Forces to France without losing a single soldier. The Germans were overwhelmed on the Western Front by Allied strength, but command of the sea enabled the Allied coalition and allowed its strength to be brought to bear.6
The Contest for Sea Control Enhances Strategic Thinking
The relationship between command of the sea and global power offers a useful lens for refining national strategy. One of Mahan’s main objectives was to facilitate this. He presented “general principles” from the “school of history” that might be used to enhance the planning and conduct of future wars. Mahan’s successors used this perspective to craft maritime strategies based on sea control and command of the sea. They clearly identified how the U.S. Navy could further national policy and help the United States achieve its strategic goals.7
The General Board crafted the first of these strategies in June 1915. With World War I raging in Europe, the Board submitted a new naval policy to Secretary of the Navy Josephus Daniels. The Board hoped to secure freedom of the seas for the United States by increasing the size of the Navy and making it “equal to the most powerful [navy] maintained by any other nation in the world.” Although not specifically mentioned, the other nation of concern was Great Britain. The Board’s draft then informed the dramatic increase in shipbuilding authorized by the 1916 program, which sought to create a navy “second to none.”8
The Board’s arguments in favor of this massive increase in spending derived directly from the importance of command of the sea. The Navy was an “instrument of diplomacy” that “must be strong enough to ensure a respectful hearing in the councils of the world.”9 The German Risikoflotte had attempted this and failed. It was too small by comparison with the Royal Navy. The answer, the Board argued, was a Navy large enough to alter strength relationships and guarantee the nation’s ability to act freely and pursue policy goals—enforcement of the Monroe Doctrine, the Open Door in China, and continued control of the Philippines—without entangling alliances. The size of the 1916 naval appropriation logically followed; by creating a fleet on par with Great Britain’s, the United States could compete for command of the sea and achieve its policy goals even in the face of potential British opposition.
Ever since then, the importance of command of the sea has informed U.S. naval strategies. During the interwar period (1919–39), the struggle for sea control was a core component of War Plan Orange, the U.S. Navy’s concept should a war against Imperial Japan be fought. Although the plan went through a series of revisions, the basic conceptual outline endured. First the U.S. Navy would retain control of the eastern Pacific, and then it would—gradually or quickly, depending on the variation of the plan—achieve sea control in the western Pacific. After that, command of the sea would allow U.S. naval forces to eradicate Japanese commerce and impose a strangling blockade on the Home Islands. That would achieve victory without having to fight the Imperial Japanese Army on the Asian mainland. Refined over many years, this basic form provided the foundation for success in the Pacific during World War II.10
In the 1980s, the Maritime Strategy continued the emphasis on sea control and command of the sea. By using its maritime dominance and the forward presence of its ships, the U.S. Navy could support diplomatic initiatives and help maintain alliances committed to resisting Soviet aggression. The Maritime Strategy integrated allied partners into a coherent strategic framework designed to convince the Soviet Union that any attack would be extremely costly. In the event of war, the U.S. Navy would quickly transition to a wartime footing, use command of the sea—the “global high ground”—to surround the Soviet Union, and employ superior electronic warfare and deception capabilities to seize the initiative. At the right moment, the fight would be taken to the enemy. Soviet ballistic missile submarines would be destroyed in their bastions. Vital targets ashore would be attacked. Sea control offered the potential to strike deep into enemy territory.11
In each of these examples, the U.S. Navy anchored its plans upon national policy goals and used the importance of command of the sea as a frame to identify and articulate coherent strategies. Today, with critics suggesting that the Navy is “strategically bankrupt,” sea control and command of the sea offer a way to overcome this dilemma and once again craft strategies that identify clear and compelling missions for the nation’s Sea Services.12
Sea Control Is More Than Shipping
To succeed, the Sea Services must update Mahan’s theories to account for the increasingly diverse ways that command of the sea influences the nation and its commerce. Mahan emphasized the flow of commercial goods because in 1890 sea control could stop that flow. Seaborne commerce remains vital—as the 23 March 2021 grounding of the Ever Given in the Suez Canal demonstrated—but sea control involves more than controlling the movement of container ships and tankers. Significant economic benefit also derives from services that flow under the sea on fiberoptic cables.
Undersea cables have been employed for more than a century, and the ability to use them—or to sever them when necessary—relies on sea control. During the Spanish-American War of 1898, the U.S. Navy cut cables to Spanish colonies to enforce blockades and disrupt enemy command and control. When the Spanish governor-general refused to allow Commodore George Dewey to use the submarine cable running between Manila and Hong Kong to send word of his victory at Manila Bay, Dewey cut the cable, thereby making the U.S. revenue ship McCulloch the best way to communicate with the capital of the Philippines. In the Caribbean, cables connecting Cuba with Spain and other Spanish colonies were located and severed, isolating the island and augmenting the U.S. blockade.13
Great Britain conducted similar operations at the outbreak of World War I, cutting undersea cables that connected Germany with the outside world. This step forced Germany to rely on powerful wireless transmissions to communicate with its colonies, and to use alternative cables for diplomatic messages to other nations. Because of Britain’s dominant position in the international cable network (even cables owned by other nations passed through British stations), both mechanisms were susceptible to signals intelligence. The British exploited that fact aggressively. Their most famous success was intercepting the Zimmerman Telegram, which, in January 1917, proposed a Mexican-German alliance should the United States enter the war against Germany. The fallout from the telegram’s discovery helped contribute to the U.S. decision to enter the war.
Today, undersea cables play a vital commercial role. Of all international communications, 99 percent is carried over submarine cables. They are both essential infrastructure and a crucial vulnerability.14 Most between North America and Europe run through a relatively narrow corridor, making them easier to locate, and—if necessary—attack. The transpacific cable network is more dispersed. Cables run from numerous points along the U.S. West Coast and connect to Japan, Hawaii, Australia, New Zealand, Guam, and the Philippines. The South China Sea, however, is full of cables that, in the event of war, could be cut, disrupting communications—and the flow of commercial traffic—between Malaysia, Indonesia, Vietnam, the Philippines, Taiwan, China, Japan, and South Korea. Modern conceptions of sea control must account for these cable networks, their place in the global economic system, and their vulnerability.
Command of the Sea Enables Economic Warfare
Historically, naval officers have adjusted their vision of sea control to account for new technologies such as cable networks, and they have revised their sense of its potential based on the changing nature of economic and commercial traffic. Early in Mahan’s career, command of the sea led to the Civil War’s “Anaconda Plan,” to cut the rebellious Southern states off from commercial traffic at sea and on inland waterways. Half a century later, the Royal Navy expanded command of the sea to include the flow of credit through the global banking network.
In his book Planning Armageddon, Nicholas Lambert contends that before World War I, the Royal Navy planned to combine its naval supremacy with Great Britain’s “near monopoly on the infrastructure of the global trading system” to force a collapse of the German economy soon after the outbreak of war, by triggering “financial derangement.” This “economic warfare” was an enhancement of more traditional forms of naval war that destroyed commercial shipping and blockaded enemy ports. By the eve of war, economic warfare had become the “cornerstone of British grand strategy.”15 However, the attempt to destroy the German economy failed, because the implications of the British strategy—especially its impact on important neutrals, such as the United States—were not fully recognized or appreciated. Nonetheless, Royal Navy creativity during this time shows the broad potential of command of the sea and the rich advantages it can confer.
In the years before World War II, the United States pursued similarly aggressive economic strategies against Japan. Admiral Harold R. Stark, the Chief of Naval Operations, believed the best approach for deterring Japanese expansionist aims was “economic starvation.” President Franklin D. Roosevelt agreed, and, after the Japanese invasion of southern Indochina in July 1941, he imposed a financial freeze on Japan that pushed the country into international bankruptcy. However, the Navy’s inability to project power into the western Pacific meant it was impossible to combine this economic pressure with a credible deterrent. Aggressive economic action without command of the sea only served to accelerate Imperial Japan’s determination to seize by force vital resources, such as Indonesia’s oil.16
During this same period, Japan was much more successful coupling naval power with economic outcomes. In 1937, the Japanese effectively imposed a blockade of China by insisting that foreign vessels not operate in the proximity of Japanese warships. Although this clearly violated existing international agreements, there was little the United States or Great Britain could do—despite the large size of their navies—because they could not exercise sea control along the Chinese coast. The Japanese could. They demonstrated the strength of their position by sinking the gunboat Panay (PR-5) and attacking the Royal Navy’s gunboat HMS Ladybird in December. Although diplomatic action convinced the Japanese to lift their blockade, without the capability to contest Japanese naval dominance, diplomacy and “economic warfare at a distance” were the only strategic tools available to the United States.17
Command of the Sea Defends Liberal Democratic Ideas
Command of the sea confers global power, but it is also important to recognize, as Andrew Lambert argues in his book Seapower States, that power manifests in a particular way and that liberal democratic ideas and freedom of the seas are inextricably linked. Command of the sea does not just create strategic alternatives and deliver economic benefit, it also differentiates open, free-market societies from repressive authoritarian regimes. Lambert believes the struggle between these types of governance is “the single greatest dynamic in human history.”18
While elements of Lambert’s thesis have been criticized, his argument that free navigation of the seas encourages “political inclusion, the rule of law, free-market economics, [and] overseas trade” is worth considering.19 The strategic contest confronting democracies—the return of great power competition—is rooted in alternative visions of how to organize and structure societies. Lambert argues that failure to maintain free navigation of the seas would threaten the “coherence of the Western liberal consortium” and undermine the legitimacy of democratic models of governance.20
If we accept the link between command of the sea and democratic ideas, then the importance of this command becomes overwhelming. It benefits the nation economically, helps craft more effective strategies, and facilitates the spread of democratic ideals. These concepts make command of the sea—and the ability to achieve sea control—a compelling interest, for the nation’s Sea Services and for the nation itself.
Unfortunately, since the Goldwater-Nichols Act of 1986, the U.S. Navy has found it difficult to craft a comprehensive naval strategy. The adoption of a particular vision of “jointness,” one that divides the world into regional combatant commands and allocates naval forces to them, has obscured the centrality of command of the sea and the nature of the “global high ground.” The Navy has struggled to articulate the vital importance of its mission and relevance to national policy goals.21
Reinvigorating the concepts of sea control and command of the sea by placing them at the forefront of “a new maritime strategy” is the clearest way to overcome this challenge. Representative Elaine Luria (D-VA) has called for such a strategy, noting the importance of creating options that allow the nation to engage in limited war and flexibly deter potential adversaries.22 Command of the sea is essential to securing these alternatives, and, unsurprisingly, Luria’s vision melds well with Lambert’s. He emphasizes that command of the sea affords engagement along a spectrum from “diplomacy, deterrence, and constabulary functions” to “economic warfare” and the projection of military power from the sea. It creates more options for strategists to employ, and many of those options are as effective in peacetime as they are in war, if not more so.
It is clear sea control and command of the sea remain decisively important. They should become the foundation of a new, comprehensive naval strategy articulating how the nation and its allies will secure freedom of navigation, further the nation’s strategic goals, and aid the spread of liberal democratic ideas. They have served this purpose before. They should do so again.
1. “Action Report,” Commander Destroyer Division One-Twenty, 6 December 1944.
2. Quoted in Kevin D. McCranie, Mahan, Corbett, and the Foundations of Naval Strategic Thought (Annapolis, MD: Naval Institute Press, 2021), 107.
3. Robert C. Rubel, “Talking about Sea Control,” Naval War College Review 63, no. 4 (Autumn 2010).
4. Email from Robert C. Rubel to author, 15 June 2021.
5. George Modelski and William R. Thompson, Seapower in Global Politics, 1494–1993 (Seattle, WA: University of Washington Press, 1988), 3.
6. Modelski and Thompson, 11, 14, 22.
7. CAPT Alfred Thayer Mahan, USN, The Influence of Seapower Upon History: 1660–1783, reprint (New York: Dover Publications, 1987), 2.
8. “Naval Policy with Present Requirements,” 30 July 1915, G. B. No. 420-2, General Board Records, Record Group 80, General Records of the Department of the Navy, National Archives, Washington, DC, Box 61.
9. General Board, Navy Department, “Confidential Memorandum Adopted by the Executive Committee,” 6 August 1915. G. B. No. 420-2, General Board Records, Record Group 80, General Records of the Department of the Navy, National Archives, Washington, DC, Box 61
10. Edward S. Miller, War Plan Orange: The U.S. Strategy to Defeat Japan: 1897–1945 (Naval Institute Press, 1991).
11. Dmitry Filipoff, “Peter Swartz on Defining the Maritime Strategy,” Center for International Maritime Security, 22 March 2021.
12. Christopher Dougherty, “Gradually and Then Suddenly: Explaining the Navy’s Strategic Bankruptcy,” War on the Rocks, 30 June 2021.
13. Jonathan Reed Winkler, “Silencing the Enemy: Cable Cutting in the Spanish-American War,” War on the Rocks, 6 November 2015.
14. “Submarine Telecoms Industry Report,” 2020–21 edition, Submarine Telecoms Forum, Inc., 23 October 2020.
15. Nicholas A. Lambert, Planning Armageddon: British Economic Warfare and the First World War (Cambridge, MA: Harvard University Press, 2012).
16. Edward S. Miller, Bankrupting the Enemy: The U.S. Financial Siege of Japan before Pearl Harbor (Naval Institute Press, 2007), 117–18, 236–43. David Morgan-Owen and Louis Halewood, eds., Economic Warfare and the Sea: Grand Strategies for Maritime Powers: 1650–1945 (Liverpool: Liverpool University Press, 2020), 219.
17. Morgan-Owen and Halewood, eds., 220–25.
18. Andrew Lambert, Seapower States: Maritime Culture, Continental Empires and the Conflict That Made the Modern World (New Haven and London: Yale University Press, 2018), 325–29.
19. For a criticism, see Lincoln Paine’s 1 October 2019 book review at the U.S. Naval Institute Blog; Lambert, Seapower States, 325.
20. Lambert, Seapower States, 321.
21. Steven Wills, “The Effect of the Goldwater-Nichols Act of 1986 on Naval Strategy, 1987–1994,” Naval War College Review 96, no. 2 (2016): 21–40. Henry J. Hendrix, To Provide and Maintain a Navy: Why Naval Primacy Is America’s First Best Strategy (audiobook and hardcover, Focsle LLP, 2020).
22. Elaine Luria, “A New U.S. Maritime Strategy,” Center for International Maritime Security, 12 July 2021; Lambert, Seapower States, 321.