Although it is one of the most critical objectives in a war at sea, the U.S. Navy has difficulty properly understanding the true meaning of sea control and that of its counterpart, sea denial. Often sea control is confused with naval capabilities, and for the most part the service’s current doctrine and posture statements do more to obfuscate than clarify the purpose, attributes, and primary methods for obtaining, maintaining, and exercising sea control. Additionally, the Navy does not seriously consider sea denial as a possibility in a case of war with a strong opponent at sea.
In the past, the principal objective of a stronger fleet in a war was to obtain and maintain command of the sea in a given maritime theater. Such command aimed to ensure the free use of sea communications and to fully deny its use by the enemy. Narrowly defined, command of the sea was understood to be nothing more than command of sea routes.1
Following the realization that mines, torpedoes, submarines, and aircraft made it difficult—even for the stronger navy—to obtain absolute and permanent command of the sea for any extended time over a large part of the theater, the term sea control came gradually into use. Broadly defined, sea control refers to the ability to use a given part of a body of water and its associated air space for military and nonmilitary purposes in time of open hostilities. It more accurately conveys the reality that in a war at sea between two strong opponents, it is not possible—except in the most limited sense—to completely control the seas for one’s use or to completely deny an opponent’s use.
While sea control is an offensive objective, sea denial is invariably a defensive objective at the strategic level and is the principal objective of the weaker side. It aims to deny in part or full an adversary’s use of the sea for military and commercial purposes. The weaker side, however, may transition to the offensive at the operational and tactical levels. In some cases, a stronger side could temporarily be forced to be on the defensive strategically, either because of the large losses suffered in the initial phase of a war or its inability to be on offensive in a given maritime theater or in two wide separate theaters.
Current Doctrine
The 2010 Naval Doctrine Publication 1: Naval Warfare (NDP-1 2010) notes that the purpose of sea control is to allow U.S. naval forces “to close within striking distance to remove landward threats to access, which in turn enhances freedom of action at sea” and enables “the projection of forces ashore.”2 This thinking, however, puts the cart before the horse. Enemy land-based aircraft, air defenses, and coastal defenses must be destroyed or neutralized before sea control is actually obtained. The 2010 Naval Operations Concept: Implementing the Maritime Strategy (NOC 10) contends that “our [U.S.] ability to establish local sea control is fundamental to exploiting the maritime domain as maneuver space, protecting critical sea communications, and projecting and sustaining combat power overseas.”3
In addition to denying the enemy military and commercial use of the sea, the true purposes of sea control are to provide support to friendly ground forces operating on the coast, pose the threat of attack—and actually attack—the enemy’s shore, and ensure uninterrupted flow of friendly military and commercial shipping. By possessing sea control, the stronger side can have a major, and often decisive, influence on the course and outcome of war on land. Sea control also can lead to drastic shifts in political and military alignments in the maritime theater.
Misconceptions and their Problems
In the U.S. Navy, sea control is often considered essentially the same as sea denial. While it is true that possessing sea control means at the same time denying that control to one’s opponent, there is a fundamental difference between these two concepts. Theoretically, the act of obtaining or gaining something is a positive objective, while denying or preventing it is a negative objective. From this stems different operational realities, as the methods used for obtaining sea control are considerably different from those used in sea denial.
Viewing sea control primarily as a capability and not as an objective to be accomplished, the Navy, in its 2010 capstone doctrinal document, NDP-1, includes sea control along with forward presence, deterrence, power projection, maritime security, and humanitarian assistance/disaster relief (HA/DR) among its core capabilities.4 The doctrine explains that power projection “in and from the maritime domain includes a broad spectrum of offensive military operations (aimed) to destroy enemy forces or logistics support or to prevent enemy forces from approaching within enemy weapons range of friendly forces.”5 Specifically, power projection pertains to “the ability of a nation to apply all or some of its elements of national power–political, economic, informational or military—to rapidly and effectively deploy and sustain forces in and from multiple dispersed locations” in responding to a crisis, contributing to deterrence, and enhancing regional stability. It consists of two components: sea power and air power.6 Forward presence of naval forces is an integral part of power projection, yet it does not follow that power projection itself consists of actions aimed at obtaining or denying sea control.
The more serious problem, though, is that while the Navy firmly believes sea control exists in peacetime by virtue of its combat potential, reality tells a different story. If the Navy possesses and exercises sea control in peacetime, how was it possible for U.S. naval vessels to be harassed with impunity by five high-speed Iranian boats in the Strait of Hormuz in January 2012? Moreover, during the Syrian crisis, in September 2013 a Russian helicopter carrier and five other warships operated in the proximity of five U.S. destroyers and an amphibious ship. At the same time, China sent an amphibious dock landing ship and other vessels to observe U.S. and Russian actions off Syria’s coast.7 In peacetime, sea control is not a prerequisite for the service’s forward presence, nor it is required for providing HA/DR. It may, however, be required in some operations, such as supporting counterinsurgency or conducting counter-piracy.
In reality, during peacetime, no navy possesses sea control, but instead only exerts a certain degree of naval influence. Both naval combat potential and naval influence are relative, and no clear relationship exists between the capability to act and the probability of exercising influence. Naval influence is more subtle and more ambiguous than naval combat potential. Forward presence is only one of several aspects of naval influence. For example, a weaker navy operating from a more favorable geographic position might have greater naval influence than the U.S. Navy, which must project power over distances of several thousands of miles.
Naval influence is the sum of one’s naval combat potential and non-naval capabilities, such as air forces and land-based ballistic or cruise missiles as well as the quality of leadership and personnel. The Chinese navy, by augmenting the combat potential of its naval forces by air forces and land-based medium-/short-range ballistic missiles, might have a greater naval influence in the western Pacific than the U.S. Navy. Naval influence, though, encompasses more than just hardware and includes many difficult or impossible to measure elements.
The perceptions of one’s naval combat potential and willingness to use it in time of crisis often differ among the friends, potential enemies, and neutral parties in a given maritime theater. Naval influence is generally greater if the stronger side at sea has a history of following through on its statements with actions rather than merely issuing empty threats. If, for instance, China were to establish sovereignty on some, or all, of the disputed lands in the South China or East China seas it may benefit from greater naval influence in territorial disputes than the United States, which may be unwilling to assume a more forceful stance to protect the interests of its friends and allies.
Degrees of Control
Too broad and imprecise, the term sea control fails to appropriately convey the reality that in a war between two strong opponents sea control is relative. One of Sir Julian S. Corbett’s greatest contributions to naval theory is his emphasis that command of the sea “may exist in various degrees” but that it “can never in practice be absolute.”8 Likewise, French strategic theorist Vice Admiral Raoul Castex argued that command of the sea is “not absolute but relative, incomplete and imperfect.”9 Sea control can be general and/or local. General sea control pertains to a state in which the stronger side exercises a rather loose and incomplete control of a large part of a maritime area without significant challenge from its opponent.10 Local sea control exists when one side has high degree of control in a relatively small part of a maritime theater, such as the amphibious objective area, that is considered critical for accomplishing an operational objective.
Sea control encompasses control of the sea surface, subsurface, and associated air, with overall control depending on the degree of control over each of these three dimensions.11 Control of the air greatly affects control of the surface, and in many ways the control of subsurface. In the same way, control of subsurface affects control of surface, and to some extent control of the air. For example, nuclear-powered attack submarines could be used to suppress an enemy’s ground-based air defenses. In the information era, control of cyberspace, which is neither absolute nor permanent and exists only in degrees, plays a part, too.
The struggle for sea control, or denying control, cannot be successful then without full unity of command. This means that a joint force maritime component commander, supported by a joint force air component commander, must be solely responsible for planning and executing major naval/joint operations and other tactical actions in this effort.
Sea control can be permanent or temporary, limited or absolute. Permanent sea control exists when the stronger side completely dominates a given maritime theater, either because the other side does not have any means to deny that control or because its fleet has been destroyed. Corbett wrote that permanent sea control does not mean that the opponent can do nothing, but rather that it cannot interfere with shipping or amphibious landings in such a way as to seriously affect the course of the war.12 In practice, however, it is more common that the weaker side still has some means at its disposal to challenge the stronger side’s control.
Temporary sea control exists when one side possesses a high degree of control over surface, subsurface, and air for a limited time. When possessing limited sea control one side has a high degree of freedom to act on the sea while the other side operates with high risk. It is inherently transitory and unstable.13 Absolute sea control means that a state’s naval forces can operate without major opposition, and their adversary cannot operate at all.
Winning the Struggle
The fight encompasses three distinct but closely related and overlapping phases: obtaining, maintaining, and exercising. In operational terms, the strategic objective is accomplished by obtaining sea control, which is followed by one’s efforts to consolidate strategic or operational success to maintain control through destruction of the remaining enemy’s forces. Exercising sea control entails exploiting these strategic or operational successes. There are no clear lines separating these phases: Some actions are predominantly carried out during the exercising phase and are conducted as soon as the sufficient degree of sea control is obtained.
Interestingly, there are no specifics outlined in the U.S. Navy’s doctrine as to how to obtain and maintain sea control, nor do they use the terms exercising or exploiting, but instead focus almost exclusively on power projection. For example, the NOC 10 explains that U.S. naval forces would “achieve sea control by neutralizing or destroying threats in the maritime, space, and cyberspace domains that constrain our freedom to maneuver, conduct follow-on missions, or restore maritime security.”14 Generally, the main methods for obtaining sea control are destruction and/or containment (or neutralization) of the enemy’s naval- and/or land-based air forces; weakening the enemy’s naval forces over time; seizing control of choke points; and capturing the enemy’s naval- or air-basing areas. Exercising sea control includes both the threat and execution of amphibious landings on the unopposed or opposed shore, destroying the enemy’s coastal area and facilities/installations, conducting commercial blockade, and providing support to friendly ground forces in their offensive (or sometimes defensive) operations on the coast.
The principal methods of combat employment of naval forces in obtaining, maintaining (or denying), and exercising sea control are tactical actions and major naval/joint operations. Tactical actions, such as attacks, strikes, raids, engagements, and battles, aim to accomplish minor or major objectives. In contrast, a major naval operation consists of a series of related tactical actions sequenced and synchronized to accomplish an operational, and in some cases a partial strategic objective. They are planned and conducted by a single commander in accordance with a common operational idea. In the littorals, major naval operations will be conducted in cooperation with sister services and the services of other nations. Each major naval/joint operation would strive to have a decisive impact on the course and outcome of the struggle for sea control. In addition, it would be necessary to conduct numerous tactical actions within a given operational framework.
One of the enduring and most serious problems is the failure to recognize major naval/joint operations as the principal method for U.S. naval forces to accomplish operational objectives at sea in wartime. For example, NDP-1 2010 and NOC 10 refer to a sea control operation as “the employment of naval forces, supported by land, air, and other forces as appropriate, in order to achieve military objectives in vital sea area.”15 However, this definition does not include either tactical methods or the scale of the objective to be accomplished. It is also too broad because it encompasses multiple objectives, which would require a major naval/joint operation. Both documents also specify that a sea control operation would include “destruction of enemy naval forces, suppression of enemy sea commerce, protection of vital sea lanes, and establishment of local military superiority in area of naval operations.”16 “Suppression of enemy sea commerce” is not a method for obtaining sea control, but an objective to weaken the enemy’s military-economic potential.
The NOC 10 explains that U.S. naval forces conduct sea control operations in environments ranging from uncertain to openly hostile, where they often contend with adversarial tactics such as opposed transit, anti-access, and area denial.17 The authors of the document obviously consider sea control operations as the method to be used in peacetime as well and assert that U.S. “naval forces will for the foreseeable future conduct sea control operations to enforce freedom of navigation, sustain unhindered global maritime commerce, prevent or limit the spread of conflict, and prevail in war.”18 In what seems to be purely tactics, NDP-1 2010 specified that sea control operations “involve locating, identifying and dealing with a variety of contacts.”19
The U.S. Navy’s current understanding of sea control and sea denial needs to be brought in line with widely accepted views, and it must be recognized that these are two distinct concepts to be accomplished through different methods. As the service reduces the size of its battle force, it must understand that it may be forced, at least temporarily, to be strategically on defensive, that is, to conduct sea denial. At the heart of any sound doctrine at the operational level of a war at sea are operational concepts. Although U.S. joint doctrine recognizes major operations as the primary method of combat employment to accomplish operational objectives, the U.S. Navy does not and focuses on so-called strike warfare, or tactics. Such a disconnect will likely negatively affect the development of needed operational concepts. Despite the passage of time, the views of naval classical theoreticians, notably Mahan, Corbett, and Castex remain highly relevant in our information age, and the service should pay far more attention to the education of its officers in the study of naval and military history, and naval theory in particular. Using proper operational terms and fully understanding their true meaning is not a matter of semantics but a prerequisite for an effective communication within a service and among services.
1. Otto Groos, Seekriegslehren Im Lichte Des Weltkrieges. Ein Buch fuer den Seemann, Soldaten und Staatsmann (Munich: E.S. Mittler & Sohn, 1929), 43.
2. Naval Doctrine Publication 1: Naval Warfare (Washington, DC: Department of the Navy, March 2010), 27.
3. Naval Operations Concept 2010: Implementing the Maritime Strategy (Washington, DC: Department of the Navy, 2010), 53.
4. Naval Doctrine Publication 1: Naval Warfare, 25.
5. Ibid., 29.
6. Naval Operations Concept 2010: Implementing the Maritime Strategy, 60.
7. “Russian Carrier Scheduled to Sail to Syrian Coast,” Military.com, 4 September 2013, www.military.com/daily-news/2013/09/04russian-carrier-scheduled-to-sail-syrian-coast; Mark Adomanis, “Russian Ships off Syria Will Likely Do little,” USNI News, 9 September 2013, news.usni.org/2013/09/09russian-ships-will-likely-little
8. Julian S. Corbett, Some Principles of Maritime Strategy (London: Longman, Green and Co., 1918), 89–90.
9. Raoul Castex, Strategic Theories. Selections translated and edited with an introduction by Eugenia C. Kiesling (Annapolis, MD: Naval Institute Press, 1994), 53
10. Guenther Poeschel, “Ueber die Seeherrschaft (II),” Militaerwesen (East Berlin) 6 June 1982, 72.
11. Guenther Poeschel, “Ueber die Seeherrschaft (I),” Militaerwesen (East Berlin) 5 May 1982, 42.
12. Corbett, 91
13. Guenther Poeschel, “Ueber die Seeherrschaft (II),” 71–72.
14. Naval Operations Concept 2010: Implementing the Maritime Strategy, 57.
15. Naval Doctrine Publication 1: Naval Warfare, 27–28; Naval Operations Concept 2010: Implementing the Maritime Strategy, 51–52
16. Naval Doctrine Publication 1: Naval Warfare, 28; Naval Operations Concept 2010: Implementing the Maritime Strategy, 51–52; Joint Publication 1-02: Department of Defense Dictionary of Military and Associated Terms, 8 November 2010 (As Amended Through 15 March 2013), 252–53.
17. Naval Operations Concept 2010: Implementing the Maritime Strategy, 53–54.
18. Ibid., 52.
19. Naval Doctrine Publication 1: Naval Warfare, 28.