Gretton: Reflecting on his Enduring Lesson about Sea Control


November 11this a significant day in the calendars of the British and Commonwealth states. It is principally Remembrance Day, commemorating the end of the First World War and reflecting upon the great cost in human life.

It is also a significant date for scholars of maritime strategy. November 11th1992 was the date on which the British naval officer and academic, Vice Admiral Sir Peter William Gretton, died at the age of 80. Gretton led a distinguished career, having joined the Royal Navy as a cadet at the Royal Naval College, Dartmouth, in 1926. During his time in the navy, he served aboard a variety of vessels, such as the battle cruiser Renown in 1930, the royal yacht Albert and Victoria in 1934, the aircraft carrier Courageous, and the cruiser Durban during the Abyssinian Crisis and the Spanish Civil War. The Second World War saw him stationed on numerous destroyers, where he was involved in anti-submarine operations. Post-war, he continued to rise through the ranks until eventually retiring from the Royal Navy in 1963 due to ill health. Following his naval service, Gretton turned to academia: he held the positions of Domestic Bursar and then Senior Research Fellow at University College, Oxford.

Gretton’s principal work, published in 1965, was Maritime Strategy: A Study of British Defence Problems. Writing in the midst of the Cold War, he was very much concerned with identifying Britain’s maritime strategic priorities in the face of the Soviet threat. The objectives he identifies might therefore be seen as a product of their time, strongly connected to a very particular strategic context. Yet there is something else that can be found in Gretton’s work, the nature of which is essentially timeless: his view of command of the sea, or as we more commonly refer to it today, sea control. It is interesting to reflect upon this when surveying the maritime environment of today

Command vs Control:

Command of the sea and sea control are key terms found in maritime strategic literature. The former has been superseded by the latter, but they are viewed in similar terms. Traditionally, they are the first priority of naval forces: to exert sufficient control over a maritime space for certain amounts of time, in order to attain goals such as ensuring the unimpeded flow of merchant shipping (and thus the unimpeded flow of a national economy’s lifeblood), denying the free movement of an adversary’s merchant fleet, denying the free movement of an adversary’s navy, maintaining access to marine resources and locations of strategic importance, and/or enabling projection of military force against another territory.

Such terms conjure images of key thinkers on the subject of maritime strategy. Mahan, Corbett and Colomb, to name just three, all discussed the concept of command of the sea. One might also consider the US Admiral Stansfield Turner, who coined the term ‘sea control’ in 1974 as a way of acknowledging the limitations placed upon attaining command of the sea by advances in air and submarine capability.

Gretton was writing before Turner outlined his concept of sea control, but it is interesting to reflect upon what he wrote concerning command of the sea – especially in light of today’s maritime environment. His view of command of the sea can be regarded as both a reiteration and a refinement of Corbett’s view that command merely meant control of sea communications. Corbett, writing earlier in the century, had identified the strategic character of maritime communications (the importance of maritime commerce to national economies). He rightly identified that the protection of this commerce was essential, but for Gretton, who was reflecting upon writers before him, merely expressing the task in terms of controlling communications was too vague and did not shed sufficient clarity on the matter. For in Gretton’s eyes, there was a potential pitfall: control of communications could be mistakenly assumed to simply mean the task of securing a fixed geographical space. For Gretton, this form of control was only part of the picture. Command of the sea was not simply about attaining and sustaining a degree of control over a static physical space. At its heart, it was about the protection of ships.

In this respect, Gretton’s conception of command of the sea acknowledges that control must shift and adapt as the objects of protection (whether they be civilian merchant vessels or transports carrying military forces) move through the maritime environment. In much the same vein as both Corbett before him and Turner afterward, Gretton’s conception of command of the sea implies that control of maritime geographical spaces is thus fluid and temporary. It implies that it evolves as the objects of protection move between different areas. In that respect, Gretton’s view can be seen as a reiteration of Corbett’s earlier teaching that command of the sea is about influencing maritime commerce and movement; but at the same time, it can also be seen as a refinement of Corbett’s view. By framing it in terms of protecting shipping, Gretton is clarifying exactly what control of communications ought to mean in light of a perceived concern that the term could be misunderstood.

This is not to suggest that control of a fixed geographical space might not be necessary in certain circumstances; merely that navies do so not for the sake of controlling the space in question, but for the sake of exerting some form of influence on the ships transiting that space (Gretton speaks of protecting ships, though to this one might also add denial of movement, should the controlling actor have a more offensive objective in mind).

Contemporary Relevance:

It is interesting to remind ourselves of Gretton’s view of command of the sea in light of today’s maritime environment. The strategic realities we face now are different in various ways to the Cold War context in which Gretton worked. Contemporary Russia may be increasingly seen as a threat once more despite the collapse of the Soviet Union, but the bipolar international order of the Cold War has been replaced – first by the US’ unipolar moment in the 1990s, and now by a growing multipolarity as states such as China and India (to name just two notable examples) ascend both economically and militarily.

Yet whilst certain states are seen as actual and/or potential adversaries by governments such as those of the US or the UK, non-state threats have also seen a greater focus. Terrorism and insurgencies remain enduring problems, with violent groups displaying some capacity to strike at maritime targets (such as the hijacking of the Achille Lauro by Palestinian militants in 1985, the bombing of the SNLS Sooraya and Ranasuru by Tamil militants in 1995, the bombing of the USS Cole by Al-Qaeda in 2002, or the attack on a Saudi oil tanker by Houthi rebels in July). Piracy has also been an ongoing issue in certain regions, such as the Horn of Africa or the Gulf of Guinea, with various estimates putting the costs incurred by ship hijackings anywhere from $1bn to $16bn per year.

At the technological level, the notion of sea control has been complemented with the notion of battlespace control. The development of air and submarine capabilities in the early 20th century made the maritime environment multidimensional, with navies able to operate above and below the ocean surface as well as upon it. However, with the growing importance of space-based platforms for communication, reconnaissance, navigation and surveillance, as well as the increasingly interlinked nature of trade, economics and social life due to advances in information, communications, Internet and social media technologies, the maritime environment now has additional dimensions in the form of space and the cyber realm. It is thus increasingly necessary for navies to see the maritime environment today as a battlespace consisting of multiple, interlinking domains, just as the navies of the early 20th century found themselves having to deal with the threats of air and submarine platforms.

All of these new realities combine to pose potential challenges for the safe movement of shipping in today’s world. China is asserting itself in its adjacent waters; its naval modernisation, capacity for sea denial and claims to contested territorial waters have elicited much attention in US defence circles. Ships and port facilities around the world are now vulnerable to non-kinetic attacks in the cyber realm as well as physical threats from piracy or terrorism. The proliferation of weapons capable of denying maritime access (such as naval mines, unmanned aerial vehicles and ballistic missiles that can target ships or even satellites upon which ships depend for navigational data) raises questions about how secure civilian shipping would be in a hypothetical conflict scenario, or how successfully naval forces could project force into territories contested by adversaries with significant anti-access capabilities.

In such an environment, the ability of a naval force to exert control over a particular fixed maritime space for a prolonged period of time becomes even less certain. Weapons proliferation allows actors to contest maritime access, whilst the greater reliance on space and cyber technologies adds new, less tangible dimensions to the maritime environment; dimensions which cannot be easily ‘controlled’ in the same sense as the land domain. It is therefore important to remember Gretton’s assertion that ultimately, command of the sea (and its conceptual descendants, sea control and battlespace control) is about protecting the movement of ships. This is a truth that remains relevant in the face of changing strategic priorities, expanding threats and proliferation of certain technologies. No matter what a state’s maritime strategic ambitions are – whether they aim to be a global force capable of projecting power across entire oceans, or a regional power exerting influence in adjacent maritime spaces – ensuring the ability of naval and civilian fleets to move unimpeded remains the important prerequisite to further operations and exploitation of the sea. Gretton’s enduring lesson is to remember this when asking ourselves what it is we want our navies to do, especially in a world where sea control seems ever less certain.

Image: HMS Victorious leads Ark Royal and Hermes, 1961, via wikimedia commons

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