Corbett Down Under: Sir Julian Corbett, Maritime Strategy, and Australian Land Power in the Indo-Pacific Arc

Introduction

The global distribution of power is shifting to Asia, and Australia’s strategic risks are rising. With reduced warning time, emerging great power competition, and expanding regional navies, Australia’s risks are growing within the maritime domain of its immediate region. Australia’s 2020 Defence Strategic Update (DSU) and 2023 Defence Strategic Review (DSR) marked significant changes in its strategic approach, identifying the growing potential threat from China and shifting from multiple competing interests to a focus on the Indo-Pacific, ‘ranging from the north-eastern Indian Ocean, through maritime and mainland Southeast Asia to Papua New Guinea and the Southwest Pacific’.[1] Worsening geostrategic circumstances have hastened an explicit security commitment to the vast two-ocean maritime region of the Indo-Pacific. However, according to Dr Michael Evans, despite being an island nation situated at the base of the Indo-Pacific, Australia lacks a ‘maritime consciousness’ to guide its defence policy, which has traditionally been defined by low spending, alliance dependence, and the contribution of its army to continental commitments and coalitions.[2] 

Evans has long argued that Australia suffers from a dissonance between its geographically derived strategic theory and its actual operational experience. In peacetime, Australian military doctrine has generally adhered to static geographic notions of ‘air-sea gaps’ and moat-protected ‘naval bastions’, only to be continually confronted in times of crisis with a requirement to deploy its military forces overseas.[3] Although strategy should not be a ‘fixed blueprint’, he says, it should nevertheless provide a guiding framework for envisioned military practice, based on the strengths and values of its people and the geopolitical realities of the environment in which it is formed.[4] 

With the challenge from revisionist great powers like Russia and China, the post-World War II Western-ordered system is under threat. Australia remains a liberal outpost committed to the prevailing order’s design and purpose. A strategic doctrine of exclusively continental defence stands in contrast to Australia’s Western culture and liberal-democratic values. These values underscore its century-old tradition of committing military forces in support of its allies and lines of communication with them, as well as imperial or liberal interests abroad in places like Europe and the Middle East. Theoretical distinctions between continental defence and expeditionary strategy have, until recently, hindered any requirement to develop a regional maritime tradition based on what Peter Dean calls ‘true’ expeditionary and amphibious operations.[5]

The regional interventions and stability operations in Fiji in 1987, Timor-Leste in 1999, and Solomon Islands in 2003 demonstrated the need for functional force projection capabilities. These operations highlighted the difficulty in quickly projecting forces offshore in response to crises. The former Chief of Army, Lieutenant General Peter Leahy, argued that decades of purely continentalist strategic guidance impaired force generation, hollowed units, and degraded the ability to operate away from Australian support bases.[6] The Kanimbla-class Landing Platform Amphibious entered service in the 1990s, and growing operational demand for amphibious shipping led the Howard Government to commit to the purchase of two amphibious assault ships—the Canberra-class Landing Helicopter Dock (LHD)—in the 2000 Defence White Paper.[7] These procurements represented a growing awareness of Australia’s regional responsibilities and its need for means to meet them. However, from the early 2000s, Australia’s commitment to coalition operations in Iraq and Afghanistan once again reinforced the dichotomous nature of Australia’s ‘way of war’ and the inherent tensions in its defence policy: the need to develop single-service force packages to support alliance partners in distant operational areas while maintaining the necessary capabilities for continental defence and to meet strategic interests in the Indo-Pacific region.[8]

With the cessation of combat operations in the Middle East and Central Asia, Australian defence planners are refocusing the island nation’s strategic approach for the ‘Asian century’.[9] To address a lack of ‘maritime consciousness’ and provide clarity to competing priorities, strategic debate will benefit from a synthesis of Australia’s geographic reality, strategic culture, and historical experience, with the theoretical framework of a maritime tradition it has hitherto ignored. The doyen of British maritime strategists, Sir Julian Stafford Corbett, was an activist of this tradition, and his ideas remain widely applicable for the 21st century.

This essay contextualises Dr Evans’s lamentation and considers how Corbett’s work serves as a useful framework for informing Australian defence strategy. In the absence of a maritime tradition, Corbett’s strategic theory offers historical guidance and theoretical grounding for Australian defence planners. This guidance provides a path for the development of a coherent maritime approach to national security, increased regional influence, management of great power competition, improved force design, and preparation for future war. 

This analysis has three parts. Part 1 reviews the geostrategic challenge posed to Australian defence planners by the confluence of economic and military power in maritime Asia, the rapid expansion of regional navies, and the apparent disconnect between the growing strategic risks and Australia’s limited maritime tradition. Part 2 examines Corbettian strategy: the relevance and writings of Corbett, specifically his theories of limited war, joint expeditionary operations, and sea denial. It posits that his ‘British way of war’ offers useful insights for 21st century Australian strategists and policymakers. Part 3 synthesises Corbett’s strategic theory with contemporary defence policy and the geopolitical circumstances of the Indo-Pacific. Within part three, this essay concludes with insights and ideas for Australian defence strategy, operational concept development, and force design. Corbett’s ideas are particularly useful to the Australian Army as it seeks to employ land power as part of a joint force in the Indo-Pacific.

Part 1—Australia, the Indo-Pacific, and ‘Maritime Consciousness’

Australia looks out on the world in two directions. On the one side lies the Indian Ocean and the developing monsoon lands of Asia. On the other lies the Pacific and the affluent ‘new world’. Australia does not have to choose between these two worlds. It can act as a bridge between them.[10]

Indira Gandhi, 1968

Australia and the Indo-Pacific

Australia sits at a crossroads. Adam Lockyer argues Australian policymakers have traditionally conceived defence strategy in ‘vertical’ geographic terms. They have assumed an expansionist threat would emerge from Australia’s north and advance south through the Asian archipelago to threaten invasion of the continent. The experience of fighting the Japanese in the Second World War reinforced this notion. In the emerging regional maritime competition, Lockyer says, it is more helpful to think of a ‘horizontal’ axis. Australia sits at the base of the 21st century’s most valuable maritime gateway—the Indo-Pacific Arc. This geographic framing reconceptualises Australia’s strategic geography as part of a buffer region separating the Indian and Pacific Oceans, placing it on the front lines of any potential contest between current and emerging regional hegemons. The geopolitical value of chokepoints through the Indo-Pacific will increase as rising Asian powers seek to challenge the American-led status quo and enlarge their naval spheres of influence.[11] 

In 1942, American political scientist Nicholas Spykman explained Australia’s intimate relationship with maritime Asia. He argued that the ‘middle sea’, the ‘Asiatic Mediterranean’, ‘lay between Asia and Australia, and between the Indian and Pacific Oceans, and was rich in resources, trade, and labour supply’. This ‘Mediterranean buffer zone’ was the scene of great competition between the greatest naval power of Asia, Japan, and the Western nations of Europe and America, who were forced to operate far from their sources of military strength. He compared the geopolitical value of the Malacca Straits to the Panama Canal, noting they were both critical strategic and commercial passageways and chokepoints for their respective regions.[13]

Spykman argued that Australia did not exist in terms of its own strength, but as a part of the British Empire, enjoying considerable protection due to its geographic location. Australia’s primary security relationship with the United States has since supplanted that with Britain, but it remains an isolated Western outpost at the base of Spykman’s buffer zone, flanked by its vast two-ocean maritime domain.[14] Spykman predicted China’s displacement of Japan as the Asian hegemon and called for a postwar alliance to balance against its rise: ‘A modern, vitalized, and militarized China’, he said, ‘is going to be a threat not only to Japan, but also to the position of the Western Powers in the Asiatic Mediterranean’. He correctly projected that China would control a ‘large section of the littoral of the middle sea’, and that its economic penetration into maritime Asia would take a political form, with the military instrument at its centre.[15] At the heart of this struggle lay energy resources, fisheries, economic and diplomatic influence, control of sea lanes, and the regional balance of power—issues that continue to deeply affect Australia’s strategic outlook.

The rise of China, coupled with a more general shift in wealth and power to Asia, has been profound, with historian Niall Ferguson claiming it represented ‘the end of 500 years of western ascendancy’.[16] This shift in economic weight has altered the strategic calculus of ‘the lucky country’ and its largest ally, the United States. Beijing has leveraged its economic growth to embark on an ambitious military modernisation program, acquiring advanced long-range weaponry and expanding its bluewater fleet. Stephan Frühling predicts that Australia will no longer enjoy its geographic isolation and instead will ‘increasingly join the ranks of those countries around the world for which the possibility of direct attack on their population or territory is part of an uncomfortable geostrategic reality’.[17]

Economic growth in Asia has swelled defence budgets. Navies have claimed a growing share of national expenditure to acquire new vessels and capabilities. A high proportion of the money spent on naval development in the Indo-Pacific is focused on capabilities for high-intensity combat, such as ballistic missile defence, nuclear deterrence systems, sophisticated submarines and anti-submarine platforms, anti-ship and land-attack cruise missiles, and electromagnetic and cyber capabilities. Indo-Pacific navies are acquiring ever more sophisticated weapons and systems seemingly intended for use against other navies and military targets on land, rather than against more commonplace archipelagic security threats such as piracy, drug smuggling or human trafficking.[18] Asia is now home to five of the world’s top seven most powerful navies.[19]

‘Maritime Consciousness’ and National Strategy

Despite the clear maritime emphasis of the 2023 DSR and the shifting global power structures, there remains considerable disagreement over appropriate strategy and joint force design. This debate reflects the diverging requirements of addressing Australia’s geopolitical vulnerability and performing Australia’s duty as a middle power contributing to the preservation of a rules-based global order. Australia’s historical identity and strategic traditions also hinder its response to 21st century geopolitical conditions. As Michael Evans has oft observed, a curious paradox of Australian national culture is the absence of a significant maritime tradition. As an island-continent dependent on sea communications, trade, and alliances, Australia should be the ‘archetype of a liberal maritime nation’.[20]

Despite Australia’s oceanic trade dependence and geographic relationship with littoral Asia, a maritime character has not found its way into the national consciousness. The maritime historian Frank Broeze lamented that Australians are a ‘coastal people with a continental outlook’—an island-nation with an inward focus.[21] Evans observed that continental awareness defines Australian literature and art, which often portray ‘sunlit pastoral landscapes … [and the] levelling romantic egalitarianism of the bush … paintings of Ned Kelly capture the interior world of the bushranger, not the seafarer’.[22]

The dearth of maritime character in the national psyche has arguably coloured Australia’s strategic culture. Two subcultures have thus shaped Australia’s ‘way of war’: first, a continentalist view of naval strategy and homeland defence; and second, dependence on great power allies, who have guaranteed Australia’s maritime security in Asia in exchange for expeditionary participation in offshore coalition operations. On the first subculture, Evans argues that when Australia has considered the strategic use of the sea, it has tended towards a doctrine of ‘naval’ rather than ‘maritime’ power—a critical distinction. What has often passed as maritime doctrine in Australia has in fact been a ‘continentalist’s idea of maritime strategy’, a conceptually narrow view of national security where the sea is viewed as a ‘defensive moat’ rather than manoeuvre space.[23] This strategic approach tends to see an ‘air-sea gap’ to Australia’s north, an unfortunate term which obfuscates the reality of the complex maritime environment of the archipelagic approaches. These approaches are home to a large number of islands that necessarily require the operation of joint military forces in the maritime tradition of theorists such as Corbett.[24]

Second, Australia’s expeditionary approach to strategy, which necessarily seeks maritime security through the alliance of a great naval power, has meant there has been both minimal requirement and limited opportunity to develop a sovereign maritime tradition. Australian discourse on ‘expeditionary operations’ is often complicated by terminology, with the phrase used to describe the deployment of niche, single-service forces to distant contingencies, most recently to Central Asia and the Middle East, as part of coalitions with major alliance partners. This is not expeditionary operations in the maritime or joint sense, but it rather describes an expeditionary strategy.[25] This strategy has a long tradition that has seen Australian forces deploy far abroad to Europe and the Middle East in both World Wars in support of the British Empire, and to the Persian Gulf, Afghanistan and Iraq in support of its larger American ally.

With the exception of the ‘Forward Defence’ strategy of the 1950s and 1960s, the seemingly opposed ‘continentalist’ and ‘expeditionary’ distinction has recently obscured the ongoing requirement for the Australian Defence Force (ADF) to operate in the space between the Australian continent itself and other distant offshore theatres—that is, in the South-East Asian and South-West Pacific littorals.[26] In addition, it has hitherto slowed the development of joint expeditionary operations and amphibious capabilities in the maritime domain, despite their historical importance in New Britain and Gallipoli in the First World War, in the South-West Pacific in the Second World War, and more recently in interventions in Timor-Leste and the Solomon Islands.[27]

Even though ANZAC sacrifice on the beaches of Gallipoli, the largest amphibious operation of the First World War, looms large in Australian national identity, neither the 1915 Dardanelles campaign nor a more general maritime consciousness has ever come to define strategic thought.[28] Gallipoli’s legacy is instead a harbinger of the nation’s continued commitment to expeditionary strategy whereby Australian land forces often supplement a larger ally in distant campaigns. Even the extensive division- and corps-level amphibious operations performed in New Guinea and Borneo between 1943 and 1945 have not found their way into what Evans calls the national ‘strategic psyche’. Rather, they are popularly overshadowed by the Army’s ‘continental ethos’ born from the exploits of the 1st Australian Imperial Force on the Western Front in the First World War, and the jungle fighting along the Kokoda Trail in 1942.[29] Even popular memory of the Gallipoli campaign invokes images of trench warfare and months of grinding attrition, rather than the operation’s intended strategic dislocation through maritime manoeuvre. In 1994, then Australian Chief of General Staff Lieutenant General John Grey lamented the ‘disconnect’ between the Army’s amphibious experience and its tradition.[30]

As Russell Parkin points out, every time Australia has faced a genuine regional crisis, it has repeatedly deployed its military in an ad hoc reaction rather than as part of a coherent strategic policy. These responses have always required the projection of forces ashore, a task for which they are often ill prepared. Sea power, he says, can project, protect, and sustain them, but only land forces can take and hold territory.[31] 

Adam Lockyer conducted a thorough and nuanced analysis of a variety of Australian defence strategies using the lens of Richard Rumelt’s strategy evaluation model and by conceptualising Indo-Pacific power competition as a prisoner’s dilemma.[32] His work is a sophisticated and convincing study in deterrence and it led him to conclude that a ‘Corbettian’ approach of maritime denial focused on the immediate region is a sound Australian defence strategy.[33] His conception of Corbettian strategy, however, is inspired by macro concepts of sea denial, blockade, and disruption of trade routes, and is specifically applied to threatening a great power’s ‘Malacca dilemma’.[34] While Lockyer is clearly familiar with Corbett’s strategic theory, his proposed strategy does not explore the details of the Englishman’s work. It is instead a logical synthesis of general maritime denial ideas. By extending his concept and engaging directly with the writings of Corbett, the following review seeks to reveal in greater depth what the early-20th century English historian and theorist might offer 21st century Australian defence planners.

Part 2—Sir Julian Stafford Corbett and Maritime Strategy

In the splendid words of Sir Edward Grey: ‘The British Army should be a projectile to be fired by the British Navy.’[35]

Admiral Sir John Fisher GCB, 1919

The Relevance of Sir Julian Corbett

Sir Julian Corbett was an early 20th century naval theorist. Born in 1854, he studied at Cambridge University and enjoyed a career in law before retiring from it in 1888 and assuming a second career as a writer and historian. He introduced historical scholarship and legal expertise into the education of the Royal Navy, influenced British national policy and war planning, and produced a series of naval histories and strategic analyses that have come to serve as foundational texts in the maritime canon.[37] His work appears to have undergone a recent renaissance. His theories are increasingly debated within the US Navy, which is grappling with naval strategy in an age of great power competition.[38] It is less immediately apparent how his theories might inform the strategies of smaller states with modest navies and an absence of any maritime tradition.

For Australian defence planners, Corbett is worth studying for several reasons. First, Australia’s geostrategic realities are maritime in nature, even if its tradition is not. Both the 2020 DSU and 2023 DSR are emphatic on this point, and the maritime domain features as a common theme throughout the various ‘schools’ of Australian strategic thought. Australia has long taken for granted its ability to deploy expeditionary land power because its allies have provided the sea control necessary to do so. In the deteriorating regional strategic environment, those circumstances are less assured. The absence of any meaningful maritime tradition risks blinding strategy-makers to what Corbett called the ‘striking and comprehensive new outlook which is almost always to be obtained from the sea’.[39] Corbett, who wrote with a deep sense of history and with the perspective of an island maritime power, can offer much to another island nation seeking to redefine its identity, strategy and value in the Asian century.

Second, the 21st century Indo-Pacific region is characterised by emerging disruptive technologies, contested and crowded seas, interconnected security guarantees, complex diplomacy, political sensitivities, and large states with hegemonic ambitions. Corbett thought deeply and wrote at length about these issues from the perspective of British maritime power. In the last decades of the 19th century, rapid progress in military technology and tectonic shifts in the global political landscape forced nations to reconsider strategy and how best to educate their officer corps in preparation for future wars. Following the German wars of unification, and in the relatively long period after any major conflict in Europe, it proved difficult to develop tactical and operational concepts, not least strategic doctrine. The solid theoretical base developed by Corbett, tested in his interactions with senior naval officers, provided a coherent framework to overcome the lack of tangible experience in military-strategic affairs and the employment of new technologies.[40]

Third, Corbett was a rationalist who focused his study on inter-state conflict. He had little to say on the modern naval conduct of peacetime diplomacy or humanitarian assistance missions. This omission may appear a limitation, but it is precisely why his theory is so insightful for the great power competition and inter-state brinkmanship that will define the foreseeable geostrategic future. The preponderance of global wealth and power is now in Asia—it lay in Europe in Corbett’s lifetime—and the region is home to a substantial maritime environment where national strength is expressed in growing navies. 

Fourth, Corbett was, in former naval officer James Holmes’s words, a ‘prophet of jointness’ before the neologism was invented.[41] Indeed, if he had written Some Principles of Maritime Strategy today, he would undoubtedly have integrated air power into his maritime doctrine. Corbett understood the limits of the naval instrument alone, observing that the fleet’s victory at Trafalgar mattered less to the outcome of the Napoleonic Wars, and more for allowing the Duke of Wellington’s successful land campaign on the Iberian Peninsula.[42] Because of his joint framework and the value he placed on multiple instruments of power in national strategy, practitioners and planners from all services and branches of government will benefit from revisiting his theoretical work and historical case studies.[43] While inter-service rivalry endures in a starkly deteriorating strategic environment, it is worth reminding policymakers of what a relatively small maritime power achieved in a period of intense great power rivalry and war.

Fifth, following a lengthy period of counterinsurgency operations in Iraq and Afghanistan, it is worth returning to first principles for a grounding in theory to guide praxis in strategy, and to provide clarity to a complex discussion in which there is little agreement on ways and means. While Corbett wrote about recent conflicts such as the Spanish-American War (1898) and the Russo-Japanese War (1904–05), there were few other contemporary examples for him to consider. Both models at his disposal were regional conflicts fought for limited political aims, and neither involved Britain herself.[44] With limited contemporary case studies available, Corbett was concerned that readers would become ‘entangled in erroneous thought’ and misapply lessons that were outliers derived from ‘special conditions’ and not common to all wars. Corbett considered the deep engagement of history necessary in the development of a meaningful theory of war. For the Australian Army, for example, an institution that was ‘profoundly changed’ by its two decades in Afghanistan, the long arc of history viewed through Corbett’s lens will likely prove instructive.[45]

Engaging directly with Corbett’s work reveals invaluable insights for contemporary strategists. Its enduring significance rewards those who can place his strategic framework in context. The following review is not exhaustive, but rather it is in the spirit of Corbett himself, who adopted the less ambitious title of ‘Some’, and not ‘The’, Principles of Maritime Strategy. A review of three of Corbett’s core ideas is sufficient to demonstrate his theoretical utility for contemporary Australian strategy. They include his concepts of limited war, joint expeditionary operations (the ‘combined approach’), and sea denial (‘disputing command of the sea’).

Corbett, Clausewitz, and the Theory of Limited War

Corbett’s 1911 book Some Principles of Maritime Strategy can be read as an investigation into how Britain, a modestly sized maritime state, was able to overcome the competition from larger continental powers and build a global empire. Corbett argued that maritime powers like Britain should wage war differently to continental powers like Imperial Germany, using limited contingents to secure limited objectives and prevent escalation through the leverage of strategic isolation and sea control. To frame his conception of limited war, Corbett turned to the Prussian theorist Carl von Clausewitz and his celebrated book On War.

Corbett observed that, late in his intellectual career, Clausewitz had distinguished between two kinds of war, where the objective could either be to destroy or completely ‘overthrow the enemy’, or ‘merely to occupy some of his frontier-districts’ for annexation or bargaining.[46] Corbett classified these two types of war as ‘unlimited’ and ‘limited’ war, respectively.[47] In Corbett’s view, unlimited wars occurred when ‘the political object was of so vital an importance to both belligerents that they would tend to fight to the utmost limit of their endurance to secure it’ in a manner approaching the Clausewitzian ideal of absolute war. Limited wars, on the other hand, occurred when one or both sides limited their aims, or when the political object was not worth ‘unlimited sacrifices of blood and treasure’.[48]

Corbett’s rationalism led him to assume that states engaged in limited war would conduct a cost-benefit analysis which would dictate circumstances where one side would rather cede the object than continue to fight beyond its worth. Yet he thought that the circumstances for limited war differed between maritime and continental nations. Corbett believed Clausewitz had in mind war between neighbouring land powers, such as France or Prussia, when he had explained his conception of limited war. In a war between continental states, he asserted, ‘the principle of the limited object can rarely if ever assert itself in perfect precision’.[49]

Corbett offered two reasons why wars waged for territory between neighbouring states could not truly be limited, believing geography would encourage escalation to unlimited war. First, such territory was usually an ‘organic part’ of a belligerent’s country, and its importance would demand escalation in order to retain it. A continental state pursuing a limited object would likely encounter an enemy pursuing an unlimited one. Second, lacking a ‘strategical obstacle’ or geographical barrier, the belligerent pursuing limited aims would be forced to create an artificial one in the defence of his homeland to prevent an ‘unlimited counterstroke’, using ‘his whole force to that end’. Austria failed to do this in the Ulm-Austerlitz campaign, when the Archduke Charles had been sent to seize North Italy from the French Empire. Instead of protecting the limited object, Napoleon marched on Vienna, destroying the Austrian home army and occupying the capital before the Archduke could respond.[50]

Although the tendency for escalation was inherent in continental warfare, Corbett believed Clausewitz had stumbled across the answer to the paradox of British ascent—that is, how ‘a small nation with a weak army’ had gathered ‘the most desirable regions of the earth’ at the expense of other great powers. ‘It is clear that Clausewitz himself never apprehended the full significance of his brilliant theory’, Corbett claimed: ‘he was unaware that he had found an explanation of one of the most inscrutable problems in history—the expansion of England—at least so far as it has been due to successful war’. Clausewitz’s continental outlook, thought Corbett, had blinded him to the application of limited war by maritime states.[51]

Corbett compared British maritime strategy to the continental way of war: 

Our own idea has long been to attack the enemy at the weakest point which would give substantial results, and to assume the defensive where he was strongest. The continental method was to strike where the enemy’s military concentration was highest and where a decisive victory would end the war by destroying his armed forces. 

That Britain had never adopted this ‘quicker and more drastic’ method was because it had never wielded sufficient military force to do so.[52] Corbett termed his modification of Clausewitz’s limited war as ‘war limited by political object’.[53]

Corbett offered two conditions necessary for limited war to be practical. First, the object must be both limited in area and ‘of really limited political importance’. On the continent, such territory was rare, but overseas possessions and colonies were available for capture by maritime powers with the means to do so. Second, the object must be capable of strategic isolation both to prevent the territory itself from being reinforced, and to act as a buffer to protect the homeland from the ‘unlimited counterstrike’. This buffer was particularly powerful if it was a vast ocean at the edges of empire, or a moat like the English Channel.[54]

Corbett saw that isolation through naval action revealed the value of ‘true limited objects’. He cited the British capture of French Canada and Spanish Havana in the Seven Years War and the American seizure of Cuba in 1898 as examples where naval power secured the home defence and isolated the territorial object. Thus, Corbett came to his conclusion that: 

limited war is only permanently possible to island Powers or between Powers which are separated by sea, and then only when the Power desiring limited war is able to command the sea to such a degree as to be able not only to isolate the distant object, but also to render impossible the invasion of his home territory.[55]

Corbett viewed the offensive, being positive in its aim, as ‘the more effective form of war’ because it led directly to a decision. However, he shared Clausewitz’s assessment that the defensive was ‘the stronger form of war’ because it required less force, conferred the benefits of time and proximity to supply lines, and afforded the opportunity for counterattack on familiar ground. Specifically, Corbett praised Helmuth von Moltke the Elder’s interpretation of Clausewitz’s defensive maxim: the power of the strategic offensive combined with the tactical defensive. Corbett thought these were the conditions afforded by limited war when correctly employed.[56]

What Corbett called the ‘limited form’ is based on the advantages of adopting the offensive or defensive at different levels of war and in different phases. By alternating between the two, the limited form raises the enemy’s costs of winning while employing relatively smaller forces efficiently. Corbett’s three phases afforded the maritime state the advantages of defence while acting offensively to secure the limited object, and the Russo-Japanese War provided him a valuable example to demonstrate his theory. 

In the first phase, the maritime state would use speed and surprise to seize an object from an unprepared opponent—in this case, the Japanese capture of Seoul and occupation of Korea in April 1904, supported by the naval Battle of Port Arthur.[57]

In the second phase, switching to a tactical or operational defensive allowed the stabilisation of the captured object and forced the strategic defender to exhaust himself in offensive operations to regain what he had once possessed. The operational defensive was not passive, Corbett emphasised, but an opportunity to seek a decisive counterattack.[58] In 1904, this phase included Japanese victory on land at Liaoyang by threatening the encirclement of the Siberian Army Corps and by securing command of the sea through the naval blockade of Port Arthur and crippling the Vladivostok raiding squadron.[59] By the Battle of Tsushima in May 1905, the territorial object was completely isolated by the sea, and the Japanese position in Korea was ‘rendered as impregnable as that of Wellington’s [in Portugal]’.[60] 

The third phase involves a recommencement of the operational and strategic offensive, which, Corbett explained, was a ‘stage of general pressure in which [the maritime power] would seek … to demonstrate that her enemy stood to lose more than he could gain by continuing the war’.[61] In the Russo-Japanese War, this was accomplished by the final advance to Mukden and invasion of Sakhalin Island, where Japan ‘obtained her end far short of having overthrown her enemy’.[62]

The limited form, when applied in a limited war, or a ‘war limited by political object’, therefore offers a method for smaller maritime states to prevail over larger continental powers. Corbett thought this ‘British way of war’ afforded unique advantages when fighting for limited objects, but could not account for every contingency. Specifically, political circumstances might dictate that Britain intervene for unlimited ends, or geographic conditions might prohibit the application of the limited form. To solve this dilemma, Corbett sought to apply the limited form to unlimited wars in a method he termed ‘war limited by contingent’.[64]

Clausewitz had commenced examining the concept in Book 8 of On War.[65] Corbett argued the Prussian had encountered difficulty incorporating it into his theoretical system but was forced to deal with it because it was so common to the European experience of war. He thought this concept represented the wars of intervention in which Britain thrived, the form of war ‘which most successfully demonstrated the potentiality for direct continental interference of a small army in conjunction with a dominant fleet’.[66] Corbett saw that wars limited by contingent provided the British the means to use their powerful navy to deploy expeditionary land forces into vulnerable theatres where disproportionate impact could be achieved in support of their continental allies.

The British called this method ‘combined operations’. Corbett noted there were two types of such operations. First, there were those ‘designed purely for the conquest of the objects for which [Britain] went to war, which were usually colonial or distant overseas territory’. Second, there were ‘operations more or less upon the European seaboard designed not for permanent conquest, but as a method of disturbing [the] enemy’s plans and strengthening the hands of [Britain’s] allies and [its] own position’. This second type could range from ‘insignificant coastal diversions’ to those of such unlimited importance that they became ‘indistinguishable in form from regular continental warfare’.[67]

Corbett offered the Duke of Wellington’s experience on the Iberian Peninsula in the Napoleonic Wars as a persuasive example of unlimited war waged by a limited contingent—in Corbett’s parlance, a ‘disposal force’. ‘Our object was unlimited’, he explained: ‘It was nothing less than the overthrow of Napoleon’. While victory at Trafalgar had failed to achieve this goal, it secured the sea control necessary for Wellington’s Peninsula campaign, which was ‘the most decisive form of offence within [British] means’.[68] With Napoleon preoccupied in Russia, Wellington could land his combined army in Portugal and, applying the offensive-defensive limited form, hold his lines at Torres Vedras and then win a series of victories which forced the retreating French over the Pyrenees in the winter of 1813–1814. 

Wellington’s invasion of south-western France supported his eastern Coalition allies who, following their victory at Leipzig in October 1813, crossed the Rhine and captured the French capital. The occupation of Paris resulted in Napoleon’s abdication, the Treaty of Paris, and the end of the War of the Sixth Coalition. Alexander Mikaberidze explains that Wellington’s victories were a distraction for the French Emperor as he campaigned in Germany: ‘[Napoleon] understood the urgency of delivering a decisive blow to the coalition in Germany so that he could turn his attention to the Pyrenees’. The Allied Trachenberg Plan denied the opportunity to land such a blow. Diplomatically, Wellington’s military presence, along with London’s vast subsidies, gave Britain considerable bargaining power within the Coalition, despite campaigning in a ‘peripheral’ theatre.[69]

Corbett viewed the value of the limited form primarily in its contribution to alliances. Whereas Clausewitz thought it ‘tidier’ if a contingent was ‘placed entirely at the ally’s disposal’ where he would be ‘free to use it as he wished’, Corbett instead saw that using the British Army as a mere auxiliary had historically been wasteful or accompanied by failure. Corbett argued that the use of a disposal force as an ancillary from the sea provided disproportionate value to coalition strategy. It was in Portugal, the defence of which was a true limited object, and where the British had ‘a sea-girt theatre independent of extraneous allies’, that the real power of sea control and strategic isolation had brought coalition success.[71]

War limited by contingent allows a maritime state to ‘wrest the initiative from the land Powers … by giving the Continental war a new direction’. Sea control enables the use of ‘naval and military force against the point where [the enemy] … was weakest, while standing securely on the defensive in the main theatre, where [the continental power’s] strength was greatest’.[72] Use of the limited form both weakened the enemy and strengthened the maritime state’s position among its allies at the postwar negotiating table. The deployment of expeditionary contingents thus offers a way for a maritime state to make an outsized and independent contribution without the attendant costs that landlocked allies are forced to pay. This approach had been an integral part of Britain’s historical grand strategy in managing the continental balance of power.

The Anglo-American Combined Chiefs of Staff pursued such a peripheral strategy in the Second World War. Allied Force Headquarters (AFHQ) launched a maritime campaign in the Mediterranean in 1942 with Operation TORCH (North Africa), followed by HUSKY (Sicily) and AVALANCHE (Salerno) in 1943. The lengthy decision-making process that led to the Mediterranean campaign was informed, in part, by a desire to relieve pressure from the besieged Soviet Union, the continental ally. Joseph Stalin argued instead for intervention in western France and the opening of the promised ‘second front’. Few serious historians would claim that Anglo-American combat power would have been better used as an auxiliary reinforcement to the Red Army in the ‘main’ theatre in the east.[73]

Corbett’s strategic doctrine was ignored in the First World War. The commitment of the British Expeditionary Force (BEF) to France in August 1914 separated it from the fleet it was designed to support and abandoned its doctrinal role in Britain’s chief strategic interest: securing and exercising sea control. The initial diminutive contribution of Britain’s six divisions added to the 90 divisions fielded by the French and became a guarantee of ongoing British commitment to the continent.[74] The opportunity to employ the limited form and deploy a combined maritime contingent of a ‘weight and mobility … beyond its intrinsic power’ had been lost. British experience in the First World War is instructive. To contextualise it, it is first necessary to explore Corbett’s views of combined operations in greater detail.

The Positive Object: Corbett on Expeditionary Warfare and the Maritime Approach

Corbett was an avowed advocate of the strategic value of joint expeditionary operations, or ‘the maritime approach’. His contribution to the concept’s development is marked by the prominence of three of his core arguments. First, Corbett’s extensive historical study led him to understand the limits to the naval instrument alone. A navy with command of the sea had significant advantages, of course, including the ability to control the lines of communication and prevent an enemy from interfering in the operational theatre. However, Corbett argued that this was not enough to achieve victory, noting that war with Napoleon continued for nine more years following the French fleet’s decisive defeat at Trafalgar.[75] Writing in 1900, Corbett observed that Elizabethan England’s naval dominance had failed to secure victory over Spain. ‘The navy maintained a high level of efficiency’, he wrote: 

[I]t was almost continually at work under fairly capable officers, and yet the war seemed to draw no nearer to its end … It was an army that was wanting … a force that could reap what the fleet had sown.[76]

The descent into naval commercial warfare against Spain, Corbett argued, was indecisive and wasteful, and it permitted the Spanish to build a large navy and fortify their ports. In reference to the writings of his near-contemporary Alfred Thayer Mahan, Corbett concluded:

We speak glibly of ‘sea-power’ and forget that its true value lies in its influence on the operations of armies. For a defensive war a navy may suffice alone; but how fruitless, how costly, and how long drawn a war must be, that for lack of an adequate army is condemned to the defensive …’[77] 

It was the disconnect between naval supremacy and military victory that led Corbett to see the value in the maritime approach: multiple instruments of national power in joint pursuit of the state’s goals.

This second idea, ‘the maritime approach’, Corbett argued, exemplified the advantages of a combined effort in national strategy. He explained: 

We are accustomed, partly for convenience and partly from a lack of scientific habit of thought, to speak of naval strategy and military strategy as though they were distinct branches of knowledge which had no common ground.

He sought to encourage a discussion among naval officers of ‘a larger strategy which regards the fleet and army as one weapon’.[78] Command of the sea was a necessary precondition to successful expeditionary warfare, and Corbett explained that maritime states achieved their greatest success when their ‘major strategy’ applied a joint approach in which the navy enabled and supported decisive operations on land.

Much of Corbett’s strategic theory was out of step with his contemporaries. His argument that navies were best employed as strategic enablers found little support among navalists who were accustomed to British oceanic dominance and the popularity of Mahan. His maritime doctrine affronted army officers who believed the best way to defeat Germany was through a large land commitment to the European continent.[79] But his deep study of history left Corbett adamant. ‘Since men live upon land and not upon the sea’, he said: 

great issues between nations at war have always been decided—except in the rarest cases—either by what your army can do against your enemy’s territory and national life, or else by the fear of what the fleet makes it possible for your army to do.[80]

Third, Corbett championed the flexibility afforded by amphibious warfare at the operational level. He advocated keeping the expeditionary force in close communication with the fleet. If the army advanced too deep into an enemy’s territory, it lost the advantages granted from being ‘in touch with the sea’, and its operations would come to resemble the continental form of war. Wellington had made this mistake in Iberia, overreaching in the disastrous Siege of Burgos, which one historian described as ‘Wellington’s only serious mistake on the Peninsula’.[81]

Thomas Edward Lawrence (of Arabia), an occasional dinner guest, once described to Corbett how his campaign in the Hejaz had been supported from the sea by the East Indies and Egyptian Squadron, which supplied him with ‘arms, money, fire support, and hot baths’. Like Corbett, Lawrence was an advocate of sea power; fire and air support from the Royal Navy Red Sea Patrol had defeated the Ottoman attack on the Arabian port of Yanbu in December 1916, while amphibious manoeuvre allowed the Sharifian army to outflank the much larger Turkish garrison at Wejh.[82] Lawrence had little taste for the Western Front attrition he called ‘murder war’, and realised victory in the desert meant obviation of Ottoman strategy, not just destruction of Turkish forces.[83]

The Arab army’s mid-1917 seizure of the sleepy port town of Aqaba transformed the character of the Hejaz rebellion, which until then had been contained in the Arabian Peninsula by the Ottoman garrison at Medina. Possession of Aqaba allowed the Royal Navy to transport the Arab striking force directly into Palestine to support General Edmund Allenby’s planned campaign.[84] Corbett saw this as ‘British’ war properly waged, and the antithesis of the continental strategy he, like Lawrence, detested on the Western Front. He called it ‘a most interesting case of the value of command of the sea as a factor in shore operations against an enemy depending entirely on land communications for his maintenance’.[85]

Corbett praised Japan’s development of a joint staff for the conduct of its maritime campaign in Korea. He noted that from April 1904, the Japanese war plan became ‘essentially amphibious’, and the combined forces of the Japanese Navy and Army were so ‘intimately … knit together in a single theatre that the work of the one service [was] unintelligible apart from the other’.[87] Amphibious operations provided Japan with ‘strategical surprise’, due to the ‘impossibility of forecasting with any certainty the lines of operation of an enemy attacking overseas’.[88] Similarly, the 1759 British combined force operation to Quebec, under General James Wolfe and Admiral Charles Saunders demonstrated the ‘baffling’ and ‘bewildering’ power that was ‘the strength of troops afloat’.[89]

By 1914, Corbett’s views on maritime strategy were at odds with the British cabinet and the senior officers who came to dictate the war plan. As much as modern Australian strategy is arguably the victim of experiential dissonance, British strategy in the First World War represented a dramatic and costly divergence of doctrine, experience and practice. The decision of the War Council to commit the BEF to France represented a distinct break from prewar policy. Britain’s grand strategic interest was keeping a prospective hegemon out of the Low Countries, but there was no binding commitment to France, and the army’s expeditionary structure was specifically designed to act in tandem with the fleet.[90] Corbett’s experience crafting and arguing for the aborted Baltic strategy holds valuable lessons in combined operations and maritime strategy.

Unable to recover the committed expeditionary force, created to conduct joint expeditionary operations in support of national maritime strategy, First Lord of the Admiralty Winston Churchill had no option but to plan purely naval offensives that did not require the use of troops. His First Sea Lord, Admiral John ‘Jacky’ Fisher, instead wanted to regain control of national strategy, along with the use of the BEF, to wage a maritime war that accorded with his conception of British doctrine, strengths and interests.[91] Consulting Corbett personally, and relying upon his analysis in England in the Seven Years’ War, Fisher focused his strategy on the Baltic. The First Sea Lord understood Germany’s dependence on oceanic trade, particularly with Sweden, and German difficulty in securing the twin coasts and Jutland Peninsula.[92]

Fisher’s intended Baltic strategy eschewed the need for a mass continental army, but it required a credible expeditionary force and an additional Baltic fleet. Fisher’s envisaged ‘siege fleet’ would consist of around six hundred specialist coastal vessels, submarines, and minesweeping sloops, designed to navigate the Danish Narrows and to lodge amphibious forces within narrow seas. The innovative low-draught Courageous­-class battlecruisers were the largest vessels of the specialist Baltic maritime force, specifically constructed to traverse the unmined Swedish side of the Sound, where Britain’s larger vessels could not go. They combined the firepower to deal with older German battleships, the speed to outrun newer ones, and the endurance to remain forward in the Baltic for prolonged campaigning from Russian ports. The siege fleet would complement the sea control focused Grand Fleet of battleships, cruisers and destroyers, while merchant vessels laid mines in the North Sea.[94] Intending to launch the Baltic campaign in 1916 when his new fleet would be ready, the First Sea Lord’s strategy consisted of two phases.

First, Fisher would recover the Belgian coast. Informed by Corbett’s analysis, he viewed its loss as a ‘strategic disaster’. The first new monitors, obsolescent warships, and a British Army contingent would secure the channel, as well as closing the German naval bases at Ostend and Zeebrugge. The BEF would then be withdrawn from the French line. This strategy would reconnect the military and naval instruments of British maritime power for the Baltic operation. Second, with minefields denying the North Sea, the siege fleet would advance on the Narrows, while a British amphibious force stood ready to secure the Danish islands of Funen and Zealand. In this way, the two main routes of entry into the Baltic (the Great Belt and the Sound) would be kept open.[95]

Fisher’s strategy was focused on forcing a German response. He sought to unsettle and confuse the German High Command, anticipating that a threat to the Danish Narrows would provoke a reaction. This reaction, he thought, would likely bring the High Seas Fleet to battle beyond the Baltic where the Grand Fleet could destroy it, or alternatively prompt a German invasion of Jutland, pushing Copenhagen’s sympathies towards the Entente. This response would enable the British Army to ‘aid’ Denmark, securing the islands that held open the Baltic, and threatening Nordic trade with Germany. If Germany did not react as he expected, Fisher’s siege fleet would enter the Baltic and use Russian bases to blockade Germany’s coast and cut the supply of metals, food and fuel, and threaten further amphibious lodgement. Thus, more than naval and technical innovation alone, the credibility of Fisher’s plan depended on the availability of an expeditionary landing force.[96]

Naval historian Andrew Lambert rejects the common interpretation that the Baltic plan was an ‘unrealistic fantasy’, or that commitment to the Western Front was ‘inevitable’, blaming Churchill, among others, for either blocking or misrepresenting Fisher’s proposals.[97] Churchill, having supported the commitment of the BEF to France, was thereafter compelled to pursue limited but costly naval offensives. Lambert argues that Churchill’s naval advance through the Dardanelles, using obsolete warships and ammunition unsuited to the destruction of forts, was ‘testament to his rejection of maritime strategy’ and represented an ‘anxiety to do something’.[98]

Corbett and Fisher had urged complementing the initial naval attack with a large landing force—the combined strategy they had both long advocated. The Allied fleet, under-resourced as it was, failed in forcing the Dardanelles by March 1915. Subsequent amphibious operations performed no better, arriving both too late and too limited in strength. By April 1915, Churchill had rendered the Baltic strategy all but impossible, reinforcing failure at Gallipoli and stripping key resources, vessels and submarines from the fleet reserved for Fisher’s planned campaign. Fisher resigned, unable to influence national strategy, while the Dardanelles fiasco also cost Churchill his appointment at the head of the Admiralty. With the loss of both men, there remained no alternative but continued continental commitment in France. Their departure ensured no maritime strategy would be further entertained, and single-service interests would thereafter dictate national effort in the ‘decisive theatre’ of the Western Front.[99]

The failure to realise the Baltic strategy was, in Corbett’s opinion, the central tragedy of the war. Writing during the war he lamented: ‘Now there was to be a complete divorce, and each service was to play a lone hand.’[101] While Corbett believed the central concept of the Dardanelles campaign was consistent with maritime doctrine, he thought it was a poor example of strategic and operational practice, and that the amphibious weapon had been wasted in a secondary theatre.[102] He wrote to Fisher in 1918:

I wept when I knew our whole Expeditionary Force was going to France, and felt what it would mean, and how Pitt would turn in his grave… when the time came to strike amphibiously for a decision, we had nothing to strike with.[103]

Britain would ultimately emerge victorious over Germany, but it would cost her a million lives and a global empire. As Lambert argues, British war-making had departed from its established grand strategy that prioritised the security of the Low Countries, the balance of power, and the combined employment of the naval and military instruments that best supported Britain’s interests and her continental allies.[104] The plight of Corbett and Fisher, the failure in the Dardanelles, and the human cost on the Western Front call into question the Baltic plan and maritime strategy. Joint expeditionary operations afford flexibility, surprise and strategic isolation of an opponent or territorial objective, but their ultimate success relies upon adequate resourcing, expertise, sea control, and an operational alignment with strategic ends.

The Negative Object: Sea Denial and Disputing Command of the Sea

In modern nomenclature, ‘sea denial’ can be described as ‘preventing partially or completely the enemy’s use of the sea for military or commercial purposes’. Milan Vego of the US Naval War College explains the difference between sea control and sea denial in terms that both Corbett and Clausewitz used: ‘Obtaining sea control is a positive object while denying that control is a negative object.’[105] Corbett rejected the simplistic binary distinction that either a navy had command of the sea, or it did not. Instead, he argued that ‘the normal condition in war is for the command to be in dispute’. This perspective offered defensive naval strategy as an option for forces confronting stronger opponents. Corbett explained that a ‘Power too weak to win command by offensive operations may yet succeed in holding the command in dispute by assuming a general defensive attitude’.[106]

When a navy’s relative strength was not sufficient for either securing command through battle or exercising it through blockade, it might be satisfied to hold the command of the sea in dispute. Disputing command of the sea affords options that ‘endeavour by active defensive operations to prevent the enemy either securing or exercising control for the objectives he has in view’. In general, Corbett offered two such methods for the weaker navy. First, operating a ‘fleet in being’, which buys time to address a temporary imbalance in naval force; and second, ‘minor counterattacks’, a protracted asymmetric campaign of attrition from a position of permanent inferiority.[107]

A ‘fleet in being’ is the strategy of a fleet that must accept temporary inferiority in certain locations.[108] Corbett thought it an effective stratagem that employed an ‘active defence’ to postpone a decision until the fleet was in a position of advantage. He explained: 

[W]here the enemy regards the general command of the sea as necessary to his offensive purposes, you may be able to prevent his gaining such command by using your fleet defensively, refusing what Nelson called a regular battle, and seizing every opportunity for a counterstroke.[109] 

The use of the phrase ‘fleet in being’ can be attributed to a study conducted by Admiral Philip Colomb of an event in 1690. Following the Glorious Revolution, contending with a French threat and the deposed King James II in Ireland, the Royal Navy was dispersed in multiple squadrons from the Irish Sea to the Mediterranean, each of which alone was inferior to the large French fleet under Admiral de Tourville. The largest force in the Channel was the Anglo-Dutch fleet commanded by Admiral Lord Torrington. In King William’s absence, the English Government was not persuaded by Torrington’s argument that to engage in battle would risk his smaller fleet and open England up to invasion. In any event, following his orders, Torrington knew that to avoid battle was untenable, and he was defeated at the Battle of Beachy Head on 30 June 1690. At his subsequent trial, Torrington remarked to Parliament in his defence: 

As it was most men were of the opinion the French would invade; but I was always of another opinion; for I always said that while we had a fleet in being they would not dare to make an attempt.[110]

Corbett saw the fleet in being as an effective strategy of deterrence. He praised Torrington’s judgement in holding command in dispute: ‘A temporary defensive was the only way to win the command, while to hazard a decision in inferior strength was the best way to lose it.’[111] To emphasise the value of a naval defensive, he cited French strategy during the Seven Years War, with its relative naval weakness, as an example: 

It was their wise policy to avoid a decision at sea, and to keep the command in dispute as long as possible, while they concentrated their offensive powers upon the army ashore. 

He added: 

[T]he essence of the defensive is to pass to the offensive, and we cannot look back upon the struggle which the French attitude so skilfully prolonged without a shudder to see how nearly they were rewarded.[112]

For Corbett, consistent with his broader theory of war, effective defensive naval strategy required more than simply passive defence. ‘The essence of defence’, he argued, ‘is mobility and an untiring aggressive spirit rather than rest and resistance’. It meant ‘keeping the fleet actively in being—not merely in existence, but in active and vigorous life’.[113] A fleet in being was not useful if it was protected within the safety of a port or anchorage; it ceded command of the sea, as the battles of Aboukir Bay and Louisbourg had demonstrated. Reflecting on the French loss of Louisbourg, the ‘key of Canada’, Corbett observed: 

No rule of strategy could appear more rigid than that a squadron must not be tied to the defence of a maritime fortress … Few naval actions had ever hit [the French marine] so hard, and it was directly due to [Augustin de Boschenry de] Drucourt’s refusal to allow the fleet to go to sea.[114]

Corbett thought the Torrington affair and the overarching French approach in the Seven Years War demonstrated the potential of defensive naval strategy, especially where political or military circumstances afforded the luxury of time.[115] Such strategy has endured beyond the age of sail and past Corbett’s lifetime. In the First World War, for example, the German High Seas Fleet was not large enough to engage the Grand Fleet in decisive battle, but it was too large for the British to contend with in reckless offensive operations. The German naval strategy, a strategic defensive while acting tactically, prevented the Royal Navy from taking decisive action against the U-boat threat at its source on the Belgian coast for the duration of the war. The German fleet in being forced sufficient dispersal of the Royal Navy to deny it the full rewards of its oceanic superiority.[116]

Following the attack on Pearl Harbor in 1941, the strategic concept adopted in the Pacific theatre by the Chief of Naval Operations, Admiral Ernest King, was essentially an active fleet in being. Awaiting the assumption of a strategic offensive in the Pacific theatre while the European war was prioritised, the United States Navy’s fast carrier fleet forces and destroyers conducted strikes and bombardments in the central and south Pacific, while submarines attacked Japanese merchant shipping and troop transports ferrying reinforcements and supplies to newly occupied positions.[117] More recently, naval historian Geoffrey Till has argued that the employment of precision-guided weaponry, launched from both land and sea as part of an anti-access area denial (A2AD) strategy, acts as a missile-age fleet in being.[118]

Corbett’s second method of disputing command, the ‘minor counterattack’, is employed when confronted with a position of permanent inferiority. He explained: 

Where a Power was so inferior in naval force that it could scarcely count even on disputing command by fleet operations, there remained a hope of reducing the relative inferiority by putting part of the enemy's force out of action. 

In 1911, he noted this had rarely occurred in history and, when it had, he could find no case ‘where the ultimate question of command was seriously affected by a minor counterattack’.[119] However, Corbett studied the age of sail, where the speed, protection, and armament of smaller vessels proved no match for large ships of the line.[120]

The rate of technological change in the years leading up to the First World War afforded ‘new possibilities for minor counterattacks’ through employing the ‘flotilla’.[121] Corbett viewed the flotilla, along with battleships and cruisers, as one of the primary types of fighting ships which constituted a fleet.[122] The flotilla consisted of many smaller vessels, used for controlling lines of communication and for ‘coastwise and inshore work’ within the littorals.[123] By the early 20th century, small surface warships were fitted with torpedoes, which gave the flotilla ‘battle power’, a ‘feature of warfare that was entirely new’. In addition to the emergence of submarines, numerous inexpensive warships armed with torpedoes were now able to sink capital ships. Strategically, a smaller fleet became capable of employing asymmetric methods to inflict losses on a stronger opponent. As Corbett observed, ‘the old principles of [battlefleet] design were torn to shreds’.[124]

In his official chronicle of the First World War, Corbett compared Germany’s strategic challenge of disputing Britain’s command of the sea to the predicament faced by France in the Seven Years War. Mines, torpedoes and submarines had given Germany a historically anomalous opportunity as an inferior navy: ‘By the enormously increased power of minor attack Germany could at least hope to reduce our margin of superiority.’ Corbett said of Germany’s ‘guerrilla warfare’ at sea: ‘Indeed, we were faced with a new problem in naval warfare for which our old experience would not serve.’ Germany’s strategy of ‘minor offensives’, explained Corbett, had been difficult to counter and had shaken Britain’s ‘national faith’ in the ‘old power of commanding the sea’.[125]

The late Admiral Stansfield Turner shared Corbett’s view that sea denial was essentially ‘guerrilla warfare at sea’. He argued that numerical advantage mattered less against an opponent pursuing such a strategy, because technology had increased both ‘vulnerability and potency’. He explained: 

The denying naval commander strikes at a time and place of his choosing to achieve maximum surprise; he does not have to stand his ground toe to toe with the enemy, but instead hits and runs. In this way a markedly inferior force can successfully thwart a superior force.[126] 

Thus, for some navies, confronting permanent inferiority with an unconventional or asymmetric war at sea presents an alternative to sea control.

Whether by design or obligation, for some states the ability to prevent an adversary from using the sea to harm their interests is all that is necessary.[127] Former Israeli Navy officer Moshe Tzalel argues his nation is one such example. ‘Israel had never needed to command the sea in order to prevail in wartime’, he says, ‘and an attempt to secure such a position at this day and age is a luxury she cannot afford’.[128] Other smaller, defensively minded navies have benefited from the development of smart mines, anti-ship missiles, unmanned aerial vehicles (UAV), and maritime special operations forces. By the 1970s, the exploits of the Bangladeshi Mukti Bahini frogmen and their riverine guerrilla war in the Sunderban delta demonstrated the growing capacity to inflict asymmetrical harm on larger navies.[129]

Figure 1. HIMARS from the United States Army 17th Field Artillery Brigade at Shoalwater Bay Training Area during Exercise Talisman Sabre 2023. (Source: Australian Defence Force image gallery)

Iranian strategy in the Strait of Hormuz is equally instructive. The Iranian Navy plans for ‘swarming attacks’, in which small, fast boats hidden among littoral inlets and anchorages launch concentrated anti-ship missile strikes from dispersed locations with the aim of overwhelming a missile defence system. Swarming speedboats could be accompanied by unmanned aerial, surface or sub-surface vehicles, a high-tech unconventional approach against large surface combatants.[130] The rise in sea denial capabilities, which Corbett foreshadowed, is especially evident in the congested Indo-Pacific region, making outright sea control increasingly difficult even for powerful navies.[131] For Australia, a middle power with a modest navy and a vast two-ocean operational theatre, sea denial capabilities represent both a threat and an opportunity. Achieving sea denial requires more than nuclear submarines. Only a focused maritime strategy, joint in nature, as part of a consistent national defence policy, is capable of meeting such challenges.

Part 3—Insights

All forms [of war] alike demand the use of battles … however great the controlling influence of the political object, it must never obscure the fact that it is by fighting we have to gain our end.[132]

Sir Julian Corbett, 1911

Developed through writing strategic analyses of wars from the age of sail and producing maritime doctrine for the First World War, Corbett’s theories may appear anachronistic at first glance, particularly when they are afforded only a cursory review or reduced to caricature. But a holistic view of his strategic doctrine reveals several applicable insights for contemporary Australian defence planners.

Australian Maritime Strategy and Doctrine

For a nation to have a maritime ‘consciousness’, it should also have a maritime strategy. It can be argued that Australia has multiple maritime strategies, some that appear in various forms in Defence White Papers or behind higher security classification. Yet there is an apparent absence of a systemic view of the fusion of land and sea power in Australian strategy.[133] Corbett’s intellectual career was defined by his development and advocacy of a national maritime strategic doctrine. He observed that it was Britain’s application of a coherent maritime approach over several centuries, backed by a dominant fleet, that had secured it the riches of empire and the protection of its island home. For Australian military professionals, there are at least two ways to contribute to the development of a cohesive maritime strategy.

First, Australian Maritime Doctrine would benefit from joint revision. The ADF proudly espouses a joint approach, particularly at the tactical level owing to its modest size and considerable experience operating as part of coalition task forces. However, there is a paucity of joint maritime doctrine at the operational and strategic levels. The Royal Australian Navy (RAN) exclusively owns and authors Australian Maritime Doctrine, employing the document as its capstone doctrinal authority. It describes the nature of the ‘RAN’s contribution to Australia’s national security and how the Navy goes about its business’. While the document covers joint maritime concepts, including amphibious operations, its primary function is to act as ‘an authoritative guide to current naval thinking’.[134] The substitution of ‘naval’ for ‘maritime’ terminology in its title obscures the single-service nature and methodological approach of the doctrine. While it is an excellent document, penned as it was by the late naval historian and Rear Admiral James Goldrick, Corbett would probably have described it as a ‘minor’ strategic doctrine and not a true ‘major’ framework which fuses multiple instruments of national power.[135]

In its own words, Australian Maritime Doctrine fits alongside such publications as Land Warfare Doctrine (LWD) 1: The Fundamentals of Land Power and Australian Air Publication (AAP) 1000-D: The Air Power Manual. This is not to suggest that the document is flawed for its stated purpose, only that it is conspicuously lacking a higher doctrinal authority—the multi-service coalescence of capstone joint maritime doctrine. Australian joint doctrine exists for amphibious operations, but it is limited to tactical concepts rather than contributing any broader maritime doctrine to national strategy.[136] In addition, Australian Maritime Doctrine’s most recent review occurred over a decade ago; it antedates the acquisition and integration of the Canberra-class LHDs, the maturation of the joint Amphibious Task Group Headquarters, and the development of amphibious operating concepts and force structures. At the time of writing, the RAN’s Plan MERCATOR: Maritime Domain Strategy 2040 appears to be a step in the ‘joint direction’.[137] The Australian Army should contribute to iterations of this strategy as an essential—even central—stakeholder.

Second, operating concepts should be nested under a shared—that is, joint—understanding of Australian maritime strategy. Technological advances may radically alter warfare at the tactical and operational levels, but strategy is more enduring.[138] Development in sensors, electronic warfare capabilities and weapon systems, particularly missiles, have shifted the risk calculus for modern navies, but maritime strategy retains its critical relevance. Sea lines of communication, trade and commerce, and securing sea control remain necessary for freedom of action and regional security. But a sparse amphibious tradition has hitherto meant a limited understanding of how land forces contribute to a wider maritime strategy.

Joint amphibious operations and their tactical and operational application are increasingly well understood in the ADF. Corbett, meanwhile, offers a holistic and historical view of their strategic utility, emphasising the primacy of the political object. The ADF’s current amphibious capability, expressed through the acquisition of the LHDs and in its rapidly developing tactical doctrine, requires a clearly articulated expression of its strategic purpose. This should consider operations beyond humanitarian and disaster relief missions, critical as they are, and contemplate Australian contributions to general conflict. As Peter Dean says, ‘warfighting should not be overlooked … Australia’s maritime strategy should not be one of peacekeeping’.[139]

Had the ADF not joined the wars in Afghanistan and Iraq in support of American grand strategy in 2002 and 2003, the nascent concepts of joint expeditionary operations might have developed as intended by Army leaders following the 1999 Timor-Leste intervention. Instead, the attention of strategists, commentators and practitioners turned to counterinsurgency and security operations, curtailing any further expeditionary concept development despite further regional crises in Solomon Islands in 2003 and Timor-Leste and Fiji in 2006.[140] More recently, increased strategic competition in the region has important implications for strategic policy—it increases the difficulty for any Australian Government to participate in expeditionary deployments outside the Indo-Pacific region. In adopting a maritime strategy, defence planners should consider the following.

Figure 2. Joint Pre-Landing Force prepares to evacuate the beach after handing over control to the Amphibious Beach Team during Exercise Sea Raider 2023. (Source: Defence image gallery)

First, in addition to its primary mission of preparing for joint land combat, the Australian Army needs to consider how it will support sea control and fleet manoeuvre. These operations occur in the ‘near seas’, littorals and remote islands. This operating environment calls for further concept development, capability acquisition and standard operating procedures. Expeditionary basing, counter-access, counter-landing, and littoral operating concept development should be ostensibly sponsored by the Army but co-authored from a joint panel of the ADF’s best thinkers and informed by the world’s best contemporary practice. The United States Marines Corps Littoral Operations in a Contested Environment (LOCE) concept and the Tentative Manual for Expeditionary Advanced Base Operations (EABO) are useful frameworks to explore while commencing the Army’s own journey.[141] These operating concepts should be nested within authoritative joint maritime doctrine, which in turn supports a broader articulation of Australian national defence strategy.[142]

Second, the ADF’s international engagement and exercise program should be considered a principal instrument of maritime—that is, ‘combined’—strategy. If the ADF is to embrace a ‘third way’ in a truly joint strategy that regards, in Corbett’s words, ‘the fleet and the army as one weapon’, then historically naval exercises like Indo-Pacific Endeavour would benefit from routinely embarked landing force contingents.[143] These prospective routinised regional deployments might not have the warfighting capacity of a Marine Expeditionary Unit, but they provide the opportunity for normalisation of Australian land force presence in the region, rapid reaction to natural disasters and humanitarian efforts in peacetime, and the pre-positioning of ‘disposal forces’ in the event of security crises and war-like contingencies. Furthermore, they inculcate a culture of joint integration beyond the annual amphibious force generation exercises and afford an opportunity to train and certify additional landing forces; in Lockyer’s words, to ‘pump saltwater into soldiers’ veins’.[144]

Australian security professionals and military practitioners would benefit from an ongoing discussion on their way of war for a maritime age that transcends any distinction, however contrived, between continental defence and expeditionary strategy. Corbett’s theoretical framework reveals that the ‘continentalists’ and the ‘expeditionaries’ are mutually complementary when it comes to maritime strategy. Limited war demands strategic isolation, not only of the intended territorial object but also by securing the homeland from any ‘unlimited counterstrike’. ‘Forward presence’ is inseparable from home defence. Sea denial capabilities are as important as those for force projection, and counter-landing operations require credible land forces. In addition, an effective maritime strategy demands astute leverage of, and support to, an alliance framework. This involves ‘paying a bill’ in military contributions. Corbett might have advised that Australia can expand its options for the way this bill is paid.

Warfare and the Limited Form

Corbett’s employment of disposal forces in wars ‘limited by contingent’ affords ways for smaller maritime states to make independent and outsized contributions to coalition strategy. These contributions, properly employed, may avoid the excessive costs of otherwise surplus auxiliary addition to campaigns under foreign command. There is a particular significance and urgency to reviewing this idea and considering with strategic clarity how best to manage great power competition, and, if necessary, meaningfully contribute to alliance war-making.

In late 2021, in response to heightened tensions between Washington and Beijing over Taiwanese sovereignty, the Australian Minister for Defence, Peter Dutton, promised military commitment in the event of war. US Secretary of State Anthony Blinken said the United States and its allies would act if China were to use force to alter the status quo over Taiwan. ‘It would be inconceivable’, Dutton said, ‘that we wouldn’t support the U.S. in an action if the U.S. chose to take that action’.[145]

Military contribution in this scenario could take several forms. In his analysis and review of potential naval conflict in East Asia, Benjamin Schreer explored Australia’s options for contributing to a US-led naval counter-anti-access strategy. One option includes forward deploying Australia’s limited air and naval assets to participate in coalition operations in East Asia and the Indian Ocean.[146] The RAN routinely participates in freedom of navigation operations in the South China Sea, and the original ‘AirSea Battle’ concept envisaged a critical role for Australia.[147] As a deterrent strategy, high-tech, missile-rich, counter-anti-access concepts act as a ‘big stick’ but have thus far proven ineffective at discouraging small-scale Chinese maritime aggrandisement—what Thomas Schelling called ‘salami slicing’ or ‘tactics of erosion’.[148]

Should deterrence fail, however, contribution to high-intensity naval warfare is a different matter for Australia’s modest military capabilities. Australia has the option of leveraging bases and airfields operated by the US and other allies to contribute to such a concept. For example, a rotation of a squadron of F-35 Joint Strike Fighters (JSF) or submarines through Guam and Japan would be achievable within the current force structure and budget.[149] However, while an auxiliary contribution would make for good politics, Corbett might have argued that it is not necessarily good strategy. Exposing key capabilities to high levels of operational risk and attrition, particularly in the early stages of a protracted military conflict, would need to be weighed against Australia’s long-term strategic interests. Three critical factors require consideration.

First, an enduring commitment of aircraft and navy vessels would strain Australia’s limited military forces and risk a large portion of the nation’s relative combat power at a time when greater regional instability would likely accompany a Sino-American confrontation. Separating key capabilities of the military instrument leaves few options for combined strategy in Australia’s immediate region. Moreover, new surface warfare vessels like the Hobart-class air warfare destroyers were acquired partly to protect the new amphibious assault ships, which are not intended for high-intensity operations anywhere near China or other anti-access states.[150]

Second, Lockyer argues that throwing Australia’s modest strategic weight into East Asia would do little to tilt the military balance in Washington’s favour, or to shape Beijing’s behaviour and military calculations. Any contribution would be largely symbolic under the ADF’s current force structure and size.[151]

Third, as a minor player in great-power rivalry, Australia would have little role in the direction or application of strategy. In the Second World War, for example, the Australian Army had deployed five divisions during the 1943 New Guinea offensives and contributed the preponderance of Allied land forces in the South-West Pacific Area (SWPA) until 1944. Yet Australia was excluded from the discussion about Pacific strategy at the Sextant conference in Cairo, November 1943, just as its troops commenced opening the Markham-Ramu Valleys and securing the Huon Peninsula.[152] The Australian Government also faced difficulty in dealing with the arrangement whereby the Commander-in-Chief SWPA, General Douglas MacArthur, determined the employment of its forces. According to David Horner, in 1945, MacArthur ‘sidelined Australia’s troops into campaigns that could not affect the outcome of the war’.[153]

By 1944, the Australian War Cabinet had departed widely from MacArthur’s plans to drastically reduce Australia’s offensive role in the Pacific. General Thomas Blamey warned the War Cabinet that any reduction would threaten Australia’s voice and weight in the post-war peace settlement. Though there were designs for Australian participation in the Philippines campaign and in the planned invasion of Japan, neither eventuated for various reasons.[154] Instead, in the final days of the war, the 7th and 9th Australian Divisions conducted amphibious operations in Borneo—costly, if operationally successful, actions now widely condemned as strategically unnecessary.[155]

According to Horner, the Borneo landings differed from the other late-war Australian campaigns in the South-West Pacific in at least one aspect. The Borneo ‘Oboe’ operations were proposed by MacArthur and conducted for strategic purposes of ‘doubtful merit’. By contrast, the Aitape-Wewak and Bougainville operations were not supported by MacArthur but were conducted for Australian strategic and political purposes. The controversy over the Borneo operation was, in Horner’s words, ‘a telling commentary on the shortcomings of Australian strategic decision-making’.[156]

Australia’s experience in the Pacific theatre from 1944 supports Corbett’s notion that contingents allocated as auxiliaries to larger allies do not necessarily materially alter the broader outcome of a war but do tend to limit that contributor’s strategic freedom of action.[157] Corbett’s conduct of war limited by contingent, however, offers alternatives for credible support to Washington in escalating great power competition, should the Australian Government require it. Apart from providing basing, logistics support, maritime and space surveillance, and strategic depth beyond missile range to US war efforts, Australian contributions could take more meaningful military forms in support of a prospective alliance strategy.

First, an Australian contribution could constitute peripheral operations by sea and air.[158] As we have seen, ‘peripheral’ in this sense refers to geography or proximity to a ‘main’ theatre; the term does not minimise the importance of such operations to an alliance’s strategic object. These operations might include intercepting an adversary’s merchant shipping through a distant blockade: air interdiction from aircraft operating from Australian bases, including the Cocos Islands, and striking at task forces returning from or entering the Indian Ocean with air, land, sea and littoral capabilities.

Such operations have three key benefits. One, they dispute command of the sea—the Indo-Pacific maritime ‘gateway’—and threaten the ‘Malacca Dilemma’. A joint, ideally multilateral, blockade causes economic and social harm to an adversary due to the significant amount of energy and hydrocarbons that transit through the region. Two, they afford an escalation continuum of options short of and including general war by delaying initial direct hostilities in a ‘main’ theatre further offshore.[159] Three, this option is closer to the Australian mainland, meaning the ADF can leverage its own sovereign strategic effects and capabilities, including over-the-horizon radar, peripheral naval and air bases, and regional security partnerships and joint access.

The proximity of these operations to Australian supply lines and support bases would mean the ADF could employ its joint force synergistically, in the manner it is trained and designed for, even were it to remain part of a larger coalition task force in the US Indo-Pacific Command theatre. A number of capabilities could contribute to peripheral operations at once, including the new air-warfare destroyers, Joint Strike Fighters, long-range maritime surveillance aircraft, land-based missile forces and armoured formations, Army-operated littoral vessels, and the new nuclear submarines acquired under the AUKUS security pact.

Second, a more ambitious strategy could see Australia leverage local sea control in South-East Asia or the Melanesian arc to conduct combined expeditionary operations in Corbett’s limited form, dismantling a belligerent Asian power’s ‘string of pearls’.[160] Depending on the object, this might see a division-sized landing force, with augmented littoral manoeuvre capabilities, operating as part of a joint force maritime component command. Any great-power escalation or outbreak of war lowers the diplomatic cost of seizing limited objects, far from the source of a burgeoning Asian hegemon’s source of power.[161] The ability to seize distant and strategically isolated facilities across the Indian Ocean, the Indo-Pacific arc or the Melanesian arc, particularly in concert with other Indo-Pacific allies, represents a potential deterrent to any great power’s expansionism.

Third, a mature anti-ship missile network, whether the missiles are employed from the land, sea or air, could enhance the density of existing counter-access capabilities employed by Australia’s partners and allies. For the Army, this will challenge thinking about land combat: traditionally a land force unit of action would be supported by joint enablers to achieve decisive effects on shore; a maritime strategy may instead call for land forces to support and protect joint capabilities—potentially some afloat. Amphibious expertise and littoral manoeuvre will be necessary to support the employment and survivability of maritime strike weapons. The requirement for close combat will remain. Ground-based systems cannot be employed until ground is seized.

The character of modern maritime warfare is such that achieving outright sea control is exceedingly difficult over vast distances against peer threats. But localised control close to Australia and its island partners might be accomplished through long-range fires, air power, and large maritime task forces, along with land-based sea denial capabilities deployed farther offshore.[162] Such a layered posture represents a negative object at the strategic level and a positive object at the operational level, consistent with Corbett’s phasing in his limited form. This strategic approach could conceivably secure vital lines of communication in the lower Indo-Pacific and free larger US forces and niche capabilities for commitment to a ‘main’ theatre. Ancillary operations by a unilateral contingent might be currently beyond the scope of Australia’s amphibious capability, but their feasibility improves as acquisition projects mature, as force structure grows, and should they be deployed as part of a broader regional multilateral effort. Such operations therefore represent a prospective leadership role for Australia, with a greater attendant say and stake in strategy, and a stronger diplomatic position in any political bargaining that were to follow a regional conflict.

Force Design and Operating Concepts

It can be reasonably asserted that the nature of war is unchanging, especially those Clausewitzian aspects of human nature, uncertainty, friction and politics. Corbett’s affinity for the Prussian’s work largely accounts for the enduring quality of his own theory of maritime strategy. However, as Michael Handel explained, ‘In all other respects technology has permeated and irreversibly changed every aspect of warfare’[164] War’s grammar is shifting rapidly in the Indo-Pacific, and the ADF’s current force structure requires evolution to match the strategic guidance in the 2020 DSU and 2023 DSR. The 2020 strategic guidance was accompanied by the Force Structure Plan, a document which explained the Australian Government’s intentions ‘for new and adjusted ADF capability investments to implement the new strategic objectives contained within the 2020 DSU’.[165]

With the government’s provision of $575 billion to the ADF over the next decade, including $270 billion to capability investment, Australia intends to procure some of the most advanced military equipment it has ever fielded. Albert Palazzo notes, however, that while this is an important accomplishment, these acquisitions are occurring in ‘an intellectual vacuum’.[166] He contends that while the DSU outlined broad strategic direction and intended investments, it fell short of articulating a ‘philosophy of war’ by which the ADF will secure the nation’s sovereignty, or any metrics to measure that goal’s success.[167] The 2023 DSR went further with its articulation of a denial strategy and urging transformation to a multi-domain ‘integrated force’.[168] An opportunity thus exists to develop a ‘strategy of denial’ informed by Corbett’s deep historical analysis and maritime theory.

Palazzo observes that the region’s development trend lines are deeply unfavourable to Australia from the perspective of strategic risk assessment and the generation of military power. The demographic, economic, technological and educational trends all suggest the rapid waning of Australian relative military power, and the increasing likelihood that Australia will be unable to secure positive—that is, ‘offensive’—success in future wars. He proposes a philosophy of war that seeks victory through a negative object—maintaining the status quo through strategic defence and limited operational interventions. This strategic approach is not unlike Britain’s interest in maintaining the European continental balance of power while securing the British Isles, from which Corbett derived his maritime theory. Consistent with Corbett’s limited form, Palazzo argues that such a strategy requires ‘aggression’, ‘initiative’ and the operational and tactical offensive.[169]

In an echo of Corbett’s observation on the years of warfare that followed Trafalgar, Palazzo rejects the Western emphasis on ‘winning battles’ and notes strategic victory is predicated only on securing a state’s goals. In Australia’s case, these goals include continental security and maintenance of the regional order.[170] His analysis raises a series of questions regarding Australia’s overall strategic culture and the investments articulated in the 2020 Force Structure Plan.[171] Guided by Corbett and the analysis thus far, for defence planners considering force design, two broad questions are worth asking.

First, where does the Army’s conception of land power fit into a prospective maritime strategy? As Thomas Lonergan points out, ongoing intellectual defence debate should focus on ‘strategy and force structure … not tactics and tanks’.[172] Leading up to the release of the 2023 DSR, a public debate occurred over a plan to remodel the Australian Army as a predominantly armoured force. This includes Project Land 400 (Phases 2 and 3—Armoured Combat Reconnaissance Vehicles (CRV) and Armoured Infantry Fighting Vehicles), and Project Land 8116 (Protected Mobility Fires—Self-Propelled Artillery), and the decision to purchase additional armoured vehicles from the United States.[173] Over the coming years, Australia is likely to spend tens of billions of dollars on armoured vehicles.[174]

Figure 3. Boxer CRV disembarks from HMAS Adelaide in Singapore as part of urban warfare training during Indo-Pacific Endeavour 2022 (Source: Defence image gallery)

The Army’s current and future envisaged force structure allows it to act as a close combat auxiliary to a coalition joint task force. Indeed, the Army foresees a role for the 1st Division as a subordinate formation to the US Army’s I Corps. However, due to Australia’s unique way of war, it is often easy to lose sight of a few considerations. Because of its modest size and extensive operational experience, the Australian Army has traditionally focused on tactical expertise—perhaps at the expense of strategic thought. Palazzo points out that, as a junior coalition partner in all the wars it has fought, the Australian military has not had the opportunity ‘to foster an understanding of how to wage war above the corps level’. In its most recent conflicts, Australia’s military commitment has been defined by the actions of combat teams and battle groups and an over-reliance on special operations forces.[175]

Palazzo argues that, while the Australian Army prides itself on its tactical prowess, this focus has muddied a deeper discussion on strategy. Experience in Iraq and Afghanistan in support of American strategy over the preceding two decades against non-existential threats has distorted Australian strategic thinking. These operations detracted from the ADF’s ability to develop capabilities, operational concepts, strategies, and partner relationships specific to Australia’s geography and sovereign purpose.[176] Corbett’s study revealed that alliances were critical but that effective strategy and doctrine were uniquely national constructs.

Bureaucratic and budgetary considerations tend to drive the development of a ‘balanced’ force that can meet the entire operational spectrum of potential coalition demand. The existing long acquisition and development lead times might also demand certain ‘off the shelf’ purchases and niche capabilities to meet urgent threats specific to Australia’s regional operating environment.[177] The Army’s armoured acquisitions have occurred against the backdrop of expensive long-term projects for new frigates and nuclear submarines for the RAN, and the JSF for the RAAF.[178] Indeed, recent conflicts have reaffirmed the utility of armoured forces based on tanks and infantry fighting vehicles in high-intensity combat and security operations.[179] These platforms are critically necessary, particularly for forward presence, but the Army requires an expanded suite of new capabilities to maximise its value proposition to a joint maritime campaign.

With relatively limited strategic weight and finite economic resources, it is important that the ADF does not forsake the pressing demand for capabilities, in sufficient quantities, for medium- and long-range air defence, long-range maritime and land strike, offensive electronic warfare, littoral manoeuvre, and sea denial.[180] The military’s arsenal is home to a number of sophisticated systems that remain at the forefront of strategic competition, largely due to its relationship with the US. But, as Lonergan argues, recent procurement has increasingly led to a boutique force structure that lacks mass in warfighting capabilities and depth in combat enablers, logistics, and materiel holdings.[181] In addition, despite the formidable combat power and protection afforded by the new vehicles, they will require careful integration into a maritime strategy if they are to be employed beyond the Australian continent. If the ADF is to reduce its strategic risks and assert influence in the region, especially in times of crisis or war, it needs to consider how to project a large, credible armoured force over the ocean, and how to protect and support it, in circumstances that are certain to feature contested control of the sea.

A land force requires protection as part of maritime manoeuvre. The RAN operates both patrol vessels and frigates, but the addition of an intermediate capability—stealth corvettes like the Swedish Saab Visby class, for example—would enhance the survivability of a landing force afloat, particularly among the archipelagic littorals.[182] Either a corvette-type vessel or other advanced, off-the-shelf small surface combatants would provide the amphibious force with ‘distributed lethality’ and survivability—that is, dense signature proliferation for overwhelming a defending adversary’s sensors and systems—as well as enhanced capability for offensive strike and intelligence, surveillance, and reconnaissance (ISR) missions.[183] In time, a littoral-capable corvette fleet could provide the amphibious task force with advanced force protection capabilities including loitering munitions, swarm technology, lasers, unmanned picquet drone vessels, inflatable missile decoys, and additional electromagnetic countermeasures.[184] 

Hugh White’s complaint that the LHDs are too large and vulnerable for high-intensity warfare may be addressed through the future acquisition of several smaller dock landing ships (LSDs), or variations of the joint support ship (JSS) under Project SEA 2200, or Army’s littoral manoeuvre vessels under Projects Land 8170 and 8702, which allow the landing force to be dispersed in smaller packages afloat, enhancing its survivability and post-lodgement integrity.[185]

A land force also requires mobility in the maritime domain. The M113 armoured personnel carrier, in service since the 1960s, weighs 18 tonnes. Its replacement under Land 400 Phase 3, the Hanwha Redback, weighs more than double that at over 40 tonnes. The Australian Light Armoured Vehicle (ASLAV), in service since the 1990s, weighs 13.5 tonnes, and its replacement, the Rheinmetall Boxer CRV, is over three times heavier, at 38 tonnes depending on its configuration.[186] A 2018 Australian Strategic Policy Institute report noted that this additional weight constrained the Boxer’s strategic deployability. Its author, Ben Coleman, analysed airlifting these vehicles to countries within Australia’s immediate region, noting that a C-130J Hercules could carry an ASLAV but not a Boxer. The ADF’s C-17A Globemaster III could carry four ASLAVs but it was capable of lifting only one CRV.[187] Furthermore, a paucity of C-17-capable airfields across the Indo-Pacific archipelagos constrains options for the deployment of combat power.

While the Boxer CRV and infantry fighting vehicle (IFV) replacement are undoubtedly valuable capabilities for the ADF, their weight and size constraints highlight the importance of sea power for their force projection, as well as the need for mature amphibious and littoral operating concepts for their lodgement and employment. Designing a force structure around the explicit purpose of auxiliary military contribution to a larger partner’s task force is, according to Clausewitz, ‘tidy’, but Corbett’s maritime doctrine reveals that there is more than one way to contribute to coalition strategy. This should include seeking ways to offset and complement a larger ally’s capability gaps and geographic focus and only supplement its existing strengths where necessary. According to Corbett, this was the purpose and method of Britain’s way of war. Maturing a unilateral amphibious capability is difficult, but forward-looking platform acquisitions, concept development and maritime doctrine will afford opportunities for disproportionately valuable contribution to alliance strategy while preserving a degree of defence sovereignty.

The second question worth asking is: consistent with Palazzo’s ‘status quo’ philosophy of war and with Corbett’s methods of the maritime strategic defensive, what strategic missions best leverage Australia’s geographic strengths while mitigating its weaknesses? Australia’s force structure should support the development of maritime operating concepts for offensive purposes (to gain access and to project force) as well as for negative ones (to deny access and dispute sea control). This should be the ADF’s goal for a ‘balanced force’, redefining ‘balance’ to mean that between military strategic missions, beyond simple equity between single-service expenditure. Despite longstanding concerns of the Australian Army’s service chiefs over budgetary allocation, the future character of war in the maritime domain is likely to demand an important place for land power.

At the outset of the First World War, Corbett forecast the growing asymmetric advantage of sea denial capabilities, crediting the German Navy’s ‘guerrilla warfare at sea’ with preventing the Grand Fleet from exercising outright sea control. In the Indo-Pacific arc, this asymmetry is represented by the proliferation of the Mature Precision Strike Regime (MPSR) and counter-access states. Numerous regional actors are increasingly demonstrating the ability to rapidly sense within the battlespace and strike across multiple domains with advanced weapon systems and capabilities previously exclusive to the United States and its privileged allies. The missile age was dramatically introduced in 1967 when the INS Eliat was struck by an Egyptian anti-ship cruise missile, and the 1973 Yom Kippur War featured the first all-missile naval engagement. Recently, the 2020 Nagorno-Karabakh War revealed what many consider to be a turning point in modern warfare: nearly all battle damage was inflicted by unmanned systems.[188]

Within the protection provided by the MPSR, potential adversaries employ actions at or below the level of violence to achieve their political goals. These actions amount to ‘salami slicing’ strategies that confront status quo powers like the US with the choice of waging or threatening war over relatively minor stakes or accepting faits accompli in the form of local encroachments, annexations, or other threats to liberal norms.[189] Deterrence-by-denial strategies are increasingly prevalent as adversaries wield sophisticated and long-range reconnaissance-strike complexes, augmented by irregular warfare and so-called ‘grey-zone’ activities. Consistent with Corbett’s limited war theory, if the value of the political object is low, incentive to overcome this deterrent effect is correspondingly reduced.[190]

Without persistent presence, the MPSR makes it difficult to re-establish access to a denied area or to gain the sea control necessary for decisive action. The US Marine Corps (USMC) has been considering this problem for some time and is redesigning its structure and operating concepts to ‘dispute command of the sea’ with ground-based forces and systems. While Australian defence planners should seek to innovate in Australia’s unique strategic context rather than imitate its larger partner, concepts such as EABO and distributed maritime operations (DMO) nonetheless offer a basis for historically grounded yet forward-thinking operational approaches that deserve exploration.[191]

EABO is a USMC operating concept born from a desire for institutional relevance following the cessation of operations in Iraq and Afghanistan, as well as a response to a strategic demand to maintain maritime access across the competition continuum. Corbett would recognise the US Navy’s and USMC’s system of naval advanced bases; it is not unlike the naval station system employed by Britain at the height of its empire. The ‘expeditionary’ advanced basing operating concept envisages the employment of a land-based reconnaissance force to act in tandem with the fleet and support its manoeuvre, consistent with Corbett’s conception of the ‘fleet and army as one weapon’.

There are two EABO-related concepts worth considering in Australian strategy and force design. The first is the concept of ‘stand-in forces’, in contrast to the strategic idea of ‘stand-off’. The comparable Australian nomenclature is ‘forward presence’. Stand-in forces are designed to maintain persistent access within an adversary’s weapons engagement zone, acknowledging that gaining access once hostilities commence is costly and difficult. According to General David Berger, Commandant of the US Marine Corps, stand-in forces are small, lethal, low-profile, reconnaissance elements that are ideally simple to maintain and based on simple operating concepts. They locate a potential adversary’s weapons platforms, sensor systems, submarines and other assets in a given area, then track them at a level that facilitates targeting by the fleet or joint fires until they depart. Stand-in forces are designed to be difficult for adversaries to locate by maintaining a low signature, moving frequently and unpredictably, and employing deception.[192]

If armed conflict breaks out, stand-in forces use their acquired knowledge of the adversary to support the fleet and other joint assets to attack quickly, blind or neutralise the adversary, and deny him areas within the maritime domain in order to disrupt his scheme of manoeuvre or move him to areas where the fleet and joint force have the advantage.[193] Building upon this concept, the Australian Army can leverage its existing regional partnerships with its ongoing development in unconventional warfare, division-level amphibious reconnaissance, and future littoral manoeuvre platforms to support escalation management and provide flexible deterrence or response options within a broader coalition strategy.[194]

The second concept worth reviewing is the Marine Littoral Regiment (MLR). The MLR offers a model for a sea denial focused task unit based on manoeuvre, air defence, fires and logistics within the contested maritime zone.[195] If Corbett’s ‘war limited by contingent’ offers a method for maritime strategy in the limited form, the MLR presents a contemporary model for what a contingent might look like. For the ADF operating within the Indo-Pacific littorals, opportunity exists to bolster its maritime contingents with the weaponisation of Project Land 8710 (Army Littoral Manoeuvre), the watercraft replacement program. Under Project Land 8702, Army will receive riverine patrol craft that will provide tactical support to troops ashore, but the Littoral Manoeuvre project offers the potential for more.

Army missile boats should be equipped to strike at both maritime and land targets. As Palazzo points out, there is no reason why Army watercraft cannot launch surface and sub-surface armed and sensor vehicles into sea lanes or send armed strike UAVs into the air, employing Land 129 (Unmanned Aerial Systems) in the maritime domain.[196] Loitering munitions might prove useful as a niche between cruise missiles and armed UAVs. Unmanned underwater vehicles, such as Boeing’s Orca or Anduril’s Extra Large Autonomous Undersea Vehicle (XL-AUV), could be employed as weapon systems, as decoys, or to resupply land forces ashore.[197] As robotic platforms become smaller, a single boat could launch and command swarms of unmanned vehicles. These missile boats and unmanned submarines represent the modern iteration of Corbett’s flotilla—‘torpedo boats’ with asymmetric ‘battle power’ that threaten larger navies by holding command of the sea and the littorals in dispute.

Conceptually, a holistic sea denial capability might include a missile-centric ‘littoral combat team’ consisting of infantry and rocket forces operating anti-ship missiles (including platforms like the unmanned Navy and Marine Corps expeditionary ship interdiction system, or NMESIS); the Spike NLOS ATGM (which can integrate with ground, aviation or maritime platforms for non-line-of-sight targets); and the long-range precision strike missile (PrSM).[198] With the arrival of Project Land 8113 (Long Range Fires), the ADF will strengthen its defensive zone with lethal fires over thousands of kilometres. Inherent in the proliferation of the MPSR, firepower has, arguably, once again tilted war’s character in favour of the defender. With the acquisition of land-based long-range precision strike capabilities, the Army will join the Navy and Air Force in contributing to strategic deterrence. This will reduce the security dependence on the US and enable a more sovereign and mature defence strategy.[199] But adopting an Australian A2AD system does not necessarily require the ADF to reduce its American security partnership. Instead, it could grow elsewhere.

For example, such littoral forces could complement a prospective USMC-Australian Army bilateral land-based naval strike network, based on other interoperable ground based anti-ship missile systems, common logistics, and larger littoral manoeuvre capabilities—offering the counter-access deterrence of a coalition-networked, missile-centric fleet in being.[200] These strike systems and littoral manoeuvre units represent a layered and powerful asymmetric sea denial capability that meaningfully employs Australian land power, protects Australia’s continent and its interests, and provides opportunity for partnership, shaping, deterrence, and response in the immediate region.

Figure 4. Soldiers from 9th Regiment, Royal Australian Artillery, prepare a drone during force protection operations as part of Exercise Talisman Sabre 2023. (Source: Defence image gallery)

To achieve Australia’s political ends through a maritime defence strategy, operational concepts require review and development. The guiding principles of Australian operational concept development and force design should include exploiting the strengths of Australia’s industry, culture, and regional relationships; covering gaps in alliance capability, rather than reinforcing existing ‘surfaces’; and seeking asymmetric offsets and solutions to a prospective adversary’s military strengths. Above all, operating concepts should be developed with the goal of combining land and maritime power—wielding the ‘fleet and army as one weapon’. By seeking balance in the dual strategic missions of maritime denial and combined expeditionary operations, Corbett’s doctrine offers a synthesis of Australia’s geographically derived strategic theory and its actual operational experience, and a way to conceptually reconcile two schools of strategic thought.

Conclusion

As expanding economies enlarge military budgets in the Indo-Pacific region, national strength is increasingly expressed in naval power. Regional navies are acquiring weapons and systems seemingly intended for use against other navies. Coupled with the growing strategic weight and coercive power of revisionist states like China, Australia’s geostrategic circumstances are deteriorating and its strategic risks are rising. The Australian Government recently announced a shift in focus to the immediate maritime region, which presaged increased defence expenditure and the AUKUS security alliance.

Yet this emerging security environment presents the ADF with a dilemma: its demands are at odds with its strategic theory, historical experience, and current force structure. Australia’s strategic culture is generally represented by two traditions: the routine expeditionary deployment of niche, single-service capabilities to contingencies in support of its maritime security guarantor’s grand strategy; and the continentalist ‘Defence of Australia’ tradition that perceives the littoral archipelago to Australia’s north as an ‘air-sea gap’ or defensive moat, rather than as manoeuvre space. Together, these seemingly competing strategic subcultures have formed a unique Australian ‘way of war’ that has hitherto stalled the development of a genuine maritime military strategy and amphibious tradition that meets the challenges of the ‘Asian Century’.

With the conclusion of combat operations in Iraq and Afghanistan, strategists and defence planners have an opportunity to redefine Australian strategy for the maritime contest that will define the Indo-Pacific in the 21st century. Despite a dearth of maritime ‘consciousness’, the ADF can look to theorists such as Julian Corbett to inform its strategy and force structure. Corbett’s ideas help to reconcile Australia’s geostrategic reality and historical warfighting experience. His theory remains widely applicable to the 21st century.

Corbett’s limited war theory offers a way for maritime states to provide independent and outsized contributions to coalition strategy. Corbett’s ‘contingents’, properly employing the limited form of war, eschew the excessive costs and strategic constraints of auxiliary contribution to foreign command. Corbett’s doctrine suggests Australian defence planners would best serve both national and coalition interests through complementing, rather than supplementing, any ostensible US strategy and capabilities in the US Indo-Pacific Command theatre. His combined expeditionary operations and sea denial doctrines afford indispensable guides for operating concept development for the Australian joint force. Applying Corbett’s maritime doctrine will challenge longstanding assumptions, organisational culture, and force design. But his strategic guidance allows defence planners to treat Australia’s risks, provide meaningful and credible support to its allies, preserve defence sovereignty, and systematically fuse land and sea power to align strategic ends, ways, and means.

Acknowledgements

The author extends deep gratitude to Dr Douglas Streus and Dr Michael Morris for their advice and mentorship, and to the Australian Army Research Centre for their support and review of this paper. All errors remain those of the author.

This paper does not represent any official positions of the United States Marine Corps or the Australian Army.

About the Author

Ash Zimmerlie is an infantry officer in the Australian Army. His operational service includes Iraq, Afghanistan, Timor-Leste, the South-West Pacific, and Queensland state recovery. He has fulfilled a range of regimental, training, representational and staff appointments. He holds a Bachelor of Arts and Master’s degrees in Military Studies, Operational Studies, and Strategy and Security. He is a graduate of the Australian Defence Force Academy, Royal Military College Duntroon, University of New South Wales, United States Marine Corps Command and Staff College (distinguished graduate), and United States Marine Corps School of Advanced Warfighting.

Endnotes