Semaphore: Sea Control and Surface Combatants

Concepts which have evolved from the maritime strategic school of thought include command of the sea, sea control and sea denial. Command of the sea is an absolute concept, which espouses free, and unchallenged maritime operations by a nation, while at the same time ensuring that an adversary is incapable of using the sea to any degree. However, although the concept might be valid in a theoretical sense, practical experience demonstrates that achieving command of the sea has become increasingly difficult, if not unattainable. The evolution of the submarine and aircraft, for example, have made it clear that the value of maritime operations is in relation to the use of the sea and not for the possession of the sea itself.

Sea Control

Acknowledging the vital lessons of history and the overarching importance of strategy, the contemporary term sea control was coined to encompass the modern realities of war at sea. Australian Maritime Doctrine defines the concept of sea control as “that condition which exists when one has freedom of action to use an area of sea for one’s own purposes and, if required, deny its use to an adversary.” It is a relative rather than an absolute concept and one that may be achieved through key battles, such as Matapan (1941) and Coral Sea (1942), or through prolonged campaigns, such as the convoy battles in the Atlantic (1939-45) and off the east coast of Australia (1942-43). The enduring feature in all these operations, however, was that sea control was a transient achievement, aiming to establish sufficient control, in a particular area, for a period of time, to enable the Allies to use the sea for their own purposes. This use of the sea reflects the fact that the ability to facilitate maritime power projection is, in many ways, the most fundamental thing that sea control enables. As Professor Colin Gray has noted: “navies fight at sea only for the strategic effect they can secure ashore, where people live.”

Sea control today is very much a multi-dimensional concept as it encompasses control of the air; control of the surface of the sea; control of the undersea water column; control of the littoral (if operating in that environment); and, control of the electro-magnetic spectrum. Each of these multi-dimensional aspects are important in each warfare discipline. For example, in maritime air warfare, which may involve a credible threat environment involving operations in close proximity to an adversary with a viable strike capability, the absence of air power and air warfare will almost inevitably prevent a force achieving sea control. Sea control is essential for the projection of maritime power, especially for the conduct of Amphibious and Sea Transport Operations and for the support of forces operating ashore.

Related to sea control is sea denial. Sea denial as a maritime strategic concept may either be used independently or as a subset of sea control. Sea denial on its own may be defined as the capacity to deny an adversary the ability to use the sea for their own purposes for a period of time. The U-boat campaigns of both World Wars are examples of a sea denial strategy, as were the minefields laid by Iraq off the Kuwaiti coast during the Gulf War. Despite some initial success, most denial strategies ultimately fail. In most cases these failures can be attributed to the one-dimensional nature of the strategy. Once effective countermeasures to the U-boat had been introduced, for example, the Germans had no other effective method with which to continue their sea denial strategy. By contrast, the successful campaign waged by the US against Japanese shipping during World War II was multi-dimensional, involving both submarine and air assets, and acting as a subset of their overarching strategy of sea control.

The Role of the Surface Combatant

Sea power is rightly recognised for its flexibility, in particular the ability of surface combatants to change their readiness swiftly between different levels of operations and apply graduated force commensurate with the situation and across the spectrum of conflict. In the diplomatic role, surface combatants make a psychological impression through their perceptible presence and powerful appearance. They have similar visibility in the policing role and possess inherent capabilities for interdiction and boarding. In higher intensity operations surface combatants combine readiness and global reach with sustainability and controllability, which can be noninvasive and easily withdrawn if required. Deployed in the protection of sea lines of communications they have multi-dimensional capabilities and are essentially weapons of sea control rather than denial. In support of land operations, surface combatants are likewise capable in a wide range of tasks including escort, bombardment, supply and on occasion lift - including where necessary evacuation. In amphibious operations, especially in conjunction with maritime air power, surface combatants can facilitate approach with manoeuvre and surprise. All these functions relate directly to Australia’s national and regional circumstances and make surface combatants essential to the central concept of sea control.

The modern surface combatant therefore retains a vital, indeed fundamental, role to play in the future maritime force structure. Their mobility and endurance allows the flexibility to maintain a continuous presence in moving scenes of action. Their sensors and weapons work throughout the maritime battlespace and span operations against aircraft, ships and submarines, and against forces and assets ashore. Moreover, mobile naval platforms have the ability to poise and persist in theatre, often for months at a time. The surface combatant thus remains a potent and flexible capability to execute the sea control requirement, particularly when they lever off other assets and advanced intelligence, surveillance fusion and dissemination systems. Indeed, the flexible response options and sustained presence of surface combatants in periods short of open hostilities may help to control or prevent escalation, particularly in complex or ambiguous circumstances where submarines and aircraft are not free to make full use of their primarily offensive potential.

Australian surface combatants must be capable of operating throughout the maritime approaches and beyond. Project Sea 4000, the Air Warfare Destroyer (AWD), is the project which will ensure that Australia will acquire and maintain a sea control capability into the future. Able to act across all environments simultaneously, the ships will provide a variety of capabilities appropriate to securing sea lines of communications, the projection of power ashore, the provision of fire support, and the protection of friendly sea, land and air forces in the open ocean and the littoral. The mission requirement is to provide a sea control capability for the ADF. In this way the role and mission of the AWD could perhaps better be understood in terms of a sea control combatant.

Future Events

King-Hall Naval History Conference 24 and 25 July 2003

RAN Sea Power Conference PACIFIC 2004 3-5 February 2004