The (Re)Rise of the Archipelagic Army: Geography, History, and the Ongoing Utility of Land Power in Australia’s Littoral Arc—A Primer

Geography, History, and the Ongoing Utility of Land Power in Australia’s Littoral Arc — A Primer

Introduction

The platform for the current direction in Australia’s Defence policy was set down with the release of the 2020 Defence Strategic Update (DSU). With this document, the then Morrison Government made it clear that Australia’s strategic environment was rapidly changing, and along with it, the risks that the nation’s defence policy must manage. The DSU noted the key drivers of this revision of the nation’s strategic circumstances: intensifying great power rivalry between China and the United States; accelerating regional military modernisation; the deterioration of the ‘rules-based order’; and the rise of ‘grey zone’ activities—including cyber operations, foreign interference, economic coercion, and disinformation campaigns.^[i]

The DSU was accepted in a bipartisan manner by the then Labor opposition led by Anthony Albanese. After its election victory in May 2022, the new Labor government announced an independently led Defence Strategic Review (DSR). The starting point for the DSR was 2020’s DSU; however, the Force Structure Plan (FSP) completed in 2020 and launched concurrently with the DSU was not reflective of the strategic assessment.

The simultaneous, rather than sequential, nature of the development of the DSU and the FSP meant that in 2020 there was a dissonance at the centre of Australian strategic policy.

The DSR’s fundamental role was, the new Prime Minister announced, to:

prepare Australia to effectively respond to the changing regional and global strategic environment and ensure Defence’s capability and force structure is fit for purpose, affordable and delivers the greatest return on investment.^[ii]

The terms of reference for the DSR noted:

[M]ilitary modernisation, technological disruption and the risk of state- on-state conflict are complicating Australia’s strategic circumstances. These strategic changes demand the Australian government re-assess the capabilities and posture of the ADF and broader Department of Defence.^[iii]

Both the DSU and the DSR reaffirmed the end of the principle of a 10- year strategic warning time for major conflict in Australia’s region and the growing risk of major war. This will be the focus of this paper; however, the utility of land power in the Indo-Pacific across the spectrum of conflict must be acknowledged. While the threat of major war in Australia’s region is more acute than it has been for decades, it only remains a possibility. The major risk of such a conflict, however possible, is why Australian, US and Japanese strategic policy is now focused on deterrence by denial: aimed at preventing any such conflict from occurring.

What we do know is that climate change—driven by global warming, or global boiling as it is now being called^[iv]—adds further complexity to Australia’s defence equation. As the DSR states:

Climate change is now a national security issue. Climate change will increase the challenges for Australia and Defence, including increased humanitarian assistance and disaster relief tasks at home and abroad. If climate change accelerates over the coming decades it has the potential to significantly increase risk in our region.^[v]

This means that operations at the lower end of the conflict spectrum, especially humanitarian and disaster relief (HADR) operations, will only increase in frequency. In these, as in all operations—as ‘men live upon the land and not upon the sea’^[vi]—land power’s role is central to all forms of missions, including delivery of aid, evacuation of personnel, risk mitigation and recovery operations.

Here geography—both physical and human—is key. Since 2013, Australia has conceived its strategic geography in terms of the Indo-Pacific.^[vii] Within this vast theatre two key subregions, South-East Asia and the South Pacific, are the most significant. The DSR notes:

For military planning, in terms of our strategic geography, the primary area of military interest for Australia’s National Defence is the immediate region encompassing the north-eastern Indian Ocean through maritime Southeast Asia into the Pacific. This region includes our northern approaches.^[viii]

The physical and human geography of the Indo-Pacific and the subregions of maritime South-East Asia and the South Pacific are critical to understanding the role that Australian land power will play in operations across the spectrum of conflict, from military diplomacy and HADR operations through to major war. It is therefore critical to highlight the fundamental importance of the littorals in Australia’s immediate region and the archipelagos against which the nation nests.^[ix]

Approximately 70 per cent of the world’s population, 80 per cent of countries and virtually all centres of international trade are in littoral regions. Among the 63 most populated urban areas (with 5 million or more inhabitants), 72 per cent are located on or near the coast, with two-thirds in Asia. In the Indo-Pacific area, over three-quarters of the population live within 200 kilometres of the coast. In this zone reside 80 per cent of the region’s cities, most of its vital infrastructure, and most of its trade, industry and military power.^[x]

The more narrowly defined Asia-Pacific region contains 60 per cent of the world’s population, reaching 4.7 billion in 2022.^[xi] By 2050, some 64 per cent of Asia’s population will be urban, while Asia will be home to the largest share of people living in informal settlements, estimated to be 332 million in East and South-East Asia, and 197 million in Central and South Asia.^[xii] This means that the region’s terrain comprises a series of complex interconnected geographies within which land forces must operate. These are characterised by increasing urbanisation of the population and the proliferation of peri-urban areas (the transition zone between rural and urban that contains a mixture of both) in South-East Asia and the Pacific that are exemplified by areas of adjacent high-density jungle, largely confined to coastal and littoral areas. Further, these subregions in South-East Asia and the South Pacific are also overwhelmingly archipelagic in nature. Urbanisation and the proliferation of peri-urban areas has been rapid and significant; it is estimated that globally by 2050 2.9 billion people will live in urban areas, equal to the total global population in 1950.

Figure 2. Urban population (as a percentage) - Pacific island small states^[xiii]

Country	Population	% urban	Trend
Nauru	12,668	100%	↔
Palau	14,797	82%	↑
Marshall Islands	32.640	79%	↑
Tuvalu	7,412	66%	↑
Fiji	541,393	58%	↑
Kiribati	74,878	57%	↑
Solomon Islands	185,298	26%	↑
Vanuatu	84,351	26%	↑*
Federated States of Micronesia	26,505	23%	↑**
Tonga	24,711	23%	↓†
Papua New Guinea		20%[xiv]
Samoa	39,179	18%	↓

* although broadly similar in the past few years
**after a drop
†slight

Figure 3. Urban population (as a percentage)—South-East Asia^[xv]

Singapore	100%
Brunei Darussalam	78.3%
Malaysia	76.7%
Indonesia	56.6%
Thailand	54.8%
Philippines	47.4%
Vietnam	36.8%
Lao People’s Democratic Republic	36.3%
Timor-Leste	31.3%
Myanmar	31.1%
Cambodia	24.2%
Total	50.3%

The Indo-Pacific is also expected to become the largest contributor to global economic growth. Within that, Asia’s share of global GDP is expected to exceed 50 per cent by 2030 and will contribute to approximately 70 per cent of global growth in 2023.^[xvi] The key is where this economic and population growth is occurring. More than 77 per cent of South-East Asia’s population lives by the coast. It is estimated that by 2025, 75–80 per cent of humanity will largely be clustered in urban centres in ‘coastal areas’—the zone up to 150 kilometres inland. This is nowhere more concentrated than in the littoral areas of the Indo-Pacific, where most of the strategic infrastructure and population centres are located within 25 kilometres of the coast. Thus, the littoral regions and access to them are critical for any military operation across the full spectrum of conflict.

Impacts of Climate Change on Geography and Security

A few examples at the lower end of the conflict spectrum illustrate this point. The impacts of climate change will see the number and frequency of HADR operations rise. A significant percentage of Pacific island nations have urban land areas that are 5 metres or less above sea level:

Figure 4. Pacific island nations—percentage of urban areas 5 metres or less above sea level

Tonga	17.5%
Fiji	8.3%
Solomon Islands	7.3%
Samoa	7.1%
Vanuatu	4.2%[xvii]
Papua New Guinea	3.8%
Timor-Leste	1.6%

This makes such nations exceptionally vulnerable to the impacts on climate change, particularly sea level rise and the frequency of adverse weather events. In South-East Asia, major low-lying mega-cities such as Jakarta and Bangkok are also susceptible sea level rise. The most recent Intergovernmental Panel on Climate Change (IPCC) report notes that Asia’s urban areas are largely considered high-risk locations for projected climate change and extreme weather events.^[xviii] The IPCC’s assessment is that coastal cities, especially in South and South-East Asia, are expected to see significant increases in average annual economic losses between 2005 and 2050 due to the impacts of climate change induced floods.

The IPCC predicts that global boiling will become increasingly more likely and, if it continues to track into high-range predictions, will almost certainly lead to severe economic losses in East Asian cities due to climate impacts. Coastal city infrastructure is more at risk of climate change impacts due to its proximity to the ocean—especially key infrastructure such as power lines, transport by road and railway, and airports and harbours. It is almost certain that the ADF will be called upon to undertake increased numbers of climate change related deployments. In these operations, force projection assets, littoral manoeuvre, ships and aircraft are key, but ultimately they are supporting forces; land forces are critical because only troops on the ground can execute HADR and environmental operations in urban areas and among populations.

The broader, unknown question, for climate-related security risks is the longer-term impact of unchecked temperature changes and sea level rise on populations, resources and political outcomes. As the DSR notes:

If climate change accelerates over the coming decades it has the potential to significantly increase risk in our region. It could lead to mass migration, increased demands for peacekeeping and peace enforcement, and intrastate and interstate conflict.^[xix]

Such occurrences will likely be linked to climate-induced impacts on agriculture and food production in Australia’s region. This includes the potential for major declines in fisheries, aquaculture and crop production that will have major—and potentially devastating—impacts on food security. Food insecurity contributes to social unrest, which in turn can engender instability in insecure political systems, ultimately degrading regional security.

It is forecast that two of the hardest hit subregions in the Indo-Pacific will be South-East Asia and the South Pacific. There are predictions that fisheries output in South-East Asia will fall by 30 per cent by 2050, while during the same period this region’s population is expected to grow by at least 12 per cent by 2035. The unfortunate result is that climate volatility is likely drive an increase in the demand for food in South-East Asia by 40 per cent by 2050.^[xx] Things are projected to be little better in the South Pacific. There, 2050 projections suggest that local food accessibility could be significantly reduced in Fiji, Papua New Guinea, Solomon Islands, and other Pacific islands.^[xxi] For both regions, water security will also become increasingly fraught. In the Pacific Islands currently, only 55 per cent of people have access to basic clean drinking water—the lowest rate in the world. Papua New Guinea ranks ninth in the 10 lowest-ranked countries for access to potable water—the other nine being African countries.^[xxii] In South-East Asia, environmental risks in the Mekong Delta and broader water issues place nearly 200 million people at risk of serious water-stressed conditions.^[xxiii]

Archipelagos: the Nexus of Geography, History and High-End Operations

For Australia the defining geographical feature of the operating environment outlined in the DSR (centred on maritime South-East Asia and the South Pacific) is the archipelago—in essence, a series of interconnected littoral spaces whose defining feature is the relative ratio of land to water.

Archipelago: a group of islands closely scattered in a body of water^[xxiv] or more broadly ‘a collection of islands (including parts of islands, interconnecting waters, and other natural features) so closely interrelated that they form an intrinsic geographical, economic, and political entity, or which historically have been regarded as such’.^[xxv]

Littoral (from the Latin litus, meaning shore): a coastal region often defined as the space in the zone between the extreme high and low tides, consisting of a seaward area (open ocean to the shore) and a landward area (the area inland from the shore that can be supported from or defended from the sea). Littorals can also include ‘large archipelagoes ^[sic] completely or partially surrounded by open ocean, such as the Malay (or Indonesian) and Solomons Archipelagos’.^[xxvi]

Military operations in archipelagic regions are characterised by several features. Unlike open seas, the distances between various land points are short. Accordingly, land-based systems for surveillance, strike and presence play a more prominent role than in open ocean areas. Archipelagos are especially conducive to the deployment of small surface and subsurface vessels, as well as being able to facilitate the operations of larger vessels.

The proliferation of island land masses in close proximity (if accessible to a military force) means that fixed-wing aircraft, helicopters and autonomous systems can be used from both sea-based platforms and land-based facilities, allowing them to be deployed and redeployed quickly, increasing sortie rates.

In the immediate areas to Australia’s north, north-west and north-east, the range of archipelagos form a series of interrelated, contiguous littoral zones. Of four archipelagic states in the world with populations over

60 million, three—Indonesia, the Philippines and Japan—generate an almost continuous archipelagic operating environment stretching from Australia’s near north to the top of East Asia (the fourth is the United Kingdom).

A further 20 nation states claim archipelagic status, including Fiji, Indonesia, the Marshall Islands, Papua New Guinea, the Philippines, Solomon Islands, Tuvalu, and Vanuatu.^[xxvii] Thus Australia is bordered to its north by archipelagic states. Through these areas run all the major sea lines of communication to and from Australia to the north, north-west and north-east. These archipelagos are the maritime trade and military gateway to and from Australia. In planning or conducting everything from HADR missions to major war scenarios, archipelagos have, and will, dominate how Australia thinks about and conducts military operations in its immediate area.

Mining the Army’s History—Operations POSTERN and OBOE

The year 2023 is the 80th anniversary of the Australian Army’s amphibious landings at Lae in New Guinea. Operation POSTERN was the centrepiece of the broader Australian campaign in New Guinea between February 1943 and April 1944. This operation epitomises the dominant importance of littoral and archipelagic warfare in Australia’s north to Army’s operations in the South Pacific.^[xxviii]

The 1943 New Guinea campaign included the division-sized assault at Lae—the first major Australian amphibious assault since Gallipoli. This was the largest operation of this type in the South-West Pacific Area (SWPA) at this time and the largest joint and combined arms operation that the Australian Army has ever fought. It was the first air, sea and land operation of the Pacific War that included an amphibious assault, an airborne assault and an air landing assault. It involved elements of the 3rd, 5th, 7th, 9th and 11th Australian Divisions, No. 9 Operational Group from the RAAF, and the bulk of the RAN. It was also one of the most successful Australian campaigns ever fought and it represents the pinnacle of Australia’s influence on Allied coalition operations in the SWPA theatre.

These operations were, at their core, fundamentally joint and combined. Without the close integration of land, air and naval power, of modern communications, signals intelligence and joint logistics, the series of operations across 1943–44 would not have been a success. Further, none could have been undertaken if not for the close partnership with the United States and the outstanding support of the people of Papua and New Guinea who served both in and alongside Australia’s military forces in the region.

The Lae operations demonstrated the Australian Army’s ability to adapt to war’s changing character and deliver swift changes to force structure, force employment, doctrine and concepts of operations. The 2nd Australian Imperial Force (AIF) transformed itself from an Army attuned to desert warfare in north Africa to one able to perform complex amphibious and littoral operations in the SWPA. This change was unprecedented in the Australian Army’s history, providing an outstanding example of top-down, bottom-up and horizontal adaptation in war. The rapid conversion evolved existing operational concepts and doctrine in combined arms operations into a new environment, yet also represented a ‘disruptive’ change in Army’s structural and operational evolution in that, from a virtual standing start, it adopted a whole new way of warfare—littoral and amphibious.^[xxix]

The Lae operations provided a number of lessons. Once the 9th Division AIF had been landed by the Allied naval forces, it became dependent on the US Army’s Engineering Special Brigade of small watercraft for logistics and tactical manoeuvre. The greatest failing by the 9th Division and the Army at Lae was its underestimation of the required logistics organisation and its own lack of watercraft squadrons.^[xxx] This fundamentally undermined the combat power of the division when it was forced to withdraw a pioneer battalion and several infantry battalions from the front line to shift supplies and reorganise the beachhead. It was also not lost on the General Officer Commanding 9th Division, Major General George Wootten, that one well-placed Japanese Army Air Force bomb could have brought the whole division to a halt. Compounding this problem was the lack of organic littoral watercraft, which meant that the division had to stop its advance in front of the increasing Japanese resistance and make a full-scale assault across the Busu River rather than using the littoral spaces to outmanoeuvre the enemy.^[xxxi]

Nonetheless, the operation was an outstanding success. From fighting a land campaign in a maritime environment during the operations over the Kokoda Trail and at Buna, Gona and Sanananda in 1942, in 1943 the Allies in the SWPA were conducting complex combined arms and joint operations utilising manoeuvre warfare to shatter the enemy’s physical and moral cohesion. The magnitude of the assault’s success was clear: it took only 12 days from the 9th Division’s amphibious assault for Lae to fall, costing total casualties in I Australian Corps of 115 killed, 501 wounded and 73 missing.^[xxxii] By way of contrast, the battles for Buna, Gona and Sanananda had lasted 64 days and cost 6,900 casualties.^[xxxiii] 

After this lightning victory at Lae, the Commander of Allied Land Forces SWPA, Australian General Sir Thomas Blamey, authorised the 9th Division to make a second amphibious landing at Finschhafen while the 7th Division leapfrogged up the Markham Valley on foot or by air insertion. After the successful, although not unproblematic, amphibious landing and seizure of the high ground at Sattelberg, the 9th Division was tasked to ‘exploit along the coast’. By now the 9th Division were exceptionally tired, leading the Corps Commander, Lieutenant General Frank Berryman, to order a reduction in the 9th Division’s tempo to ‘ease the physical strain on the forward troops’ by ‘drastically reduc^[ing] the depth of the inland patrolling’ and leapfrogging units forward by sea.^[xxxiv]

The basic operational approach by the 9th Division in the Huon Peninsula was to advance using one brigade, generally with as little as only one company leading the coastal advance. Maximum use was made of tanks and artillery and, where possible, units and supplies were moved along the coast via landing craft.^[xxxv] To reduce Japanese rearguards, the basic tactical approach was to make contact with Japanese blocking positions, pin them in place with artillery, infantry and tanks, and then insert infantry and further armour in their rear via littoral watercraft. This forced the Japanese to withdraw or be destroyed in place. However, the division’s advance was limited to the extent to which its attached US Navy boat and shore regiment (from the Engineering Special Brigade) could provide support to its operations.

Subsequently to this campaign, Army very quickly raised two Beach Landing Groups, with each group capable of handling a division-sized assault to improve its logistical and beachhead organisation. A further two Army watercraft groups ensured that sufficient organic lift was available for operations across the archipelago. By 1945, the Army was operating over 1,800 small, medium and large littoral vessels. These craft were the lifeblood of logistics resupply and became the platform of choice for tactical manoeuvre by the Army in the South Pacific.

In the Army’s 1945 assault in Borneo, the 2nd AIF’s transformation in littoral and amphibious warfare was so advanced that it conducted the last of what US Marine Corps Colonel Joseph H Alexander described as ‘storm landings’. Storm landings are long-range amphibious assaults designed to land into the heart of an enemy’s defences, utilising overwhelming firepower through naval gunfire support, land- and carrier-based aviation, tracked armoured landing vehicles, and combined arms operations. This formidable strike-power was enabled through highly specialised equipment, tactics, techniques and procedures.^[xxxvi]

Australia’s operations were also one part of a much broader multi-theatre campaign plan. The 1943–1945 manoeuvres were truly multi-domain operations^[xxxvii] and the orchestration of this combat power was founded on network-centric warfare using the latest technology. While perhaps considered modern principles, multi-domain operations and network-centric warfare approaches were employed by Army in 1943. The enduring lessons from this period have been analysed by the People’s Liberation Army (PLA).

As Toshi Yoshihara has outlined, the PLA ‘have subjected the ^{[Pacific War]} maritime conflict and its campaigns to scrutiny’ and:

their writings frequently link the insights from the Pacific War campaigns to contemporary military affairs, including warfare in the information age, modern amphibious operations, shore-based firepower, and expeditionary logistics ^{[and thereby]} offer tantalising hints of the PLA’s deeply held beliefs, assumptions, and proclivities about future warfare, such as the penchant for striking first and attacking the enemy’s vulnerabilities. They also reveal the kinds of longstanding weaknesses that the PLA is seeking to reverse, including logistics.^[xxxviii]

Further, these World War II campaigns demonstrate that the concept of anti-access/area denial (A2AD) warfare is not new. In the maritime domain, this tension is as old as clashes between ships and forts. In the Pacific War, the Imperial Japanese Navy and Imperial Japanese Army (IJA) adapted and innovated in response to increasing Allied dominance at sea and in the air. Using land- and carrier-based aviation, the Imperial Japanese forces developed a system of A2AD warfare that analysed how to oppose and defeat Allied amphibious landings. In the IJA, the debate was focused on whether to defend the shoreline, or establish in-depth defences to denude Allied offensive operations. After failed attempts at defence on the shoreline, and the eclipsing of Japanese carrier- and land-based aviation, the Japanese moved to defence-in-depth ashore to impose attrition on the Allies and hold the Allied naval covering forces in place.^[xxxix] Holding Allied naval forces over extended lines of communication in the main battle space was designed to allow Japanese Army and Navy aviation to utilise its main anti-access platform: the kamikaze. Kamikazes can, in modern parlance, be considered as autonomous manned anti-ship cruise missiles. On 21 October 1944, HMAS Australia was ‘the first Allied ship to be hit by a suicide aircraft’—which killed the commanding officer and 29 crew and wounded 64.^[xl]

While the Pacific campaigns are part of Army’s history and culture, they are a wellspring for lessons to be relearned and rediscovered—from tactics and administration to operations and strategy. These campaigns are fundamentally important because of the enduring impact of geography on military operations. Their study leads to some key takeaways for the operating environment today:

• The importance of joint operations. As noted, the SWPA operating environment is an archipelago. All major military actions in the South Pacific theatre occurred in the ‘littoral zone’, where air, land and naval assets operating together are essential for success. All major naval battles were fought over land features or in sight of land. These observations also extend to the Central Pacific area of operations from 1943—from the defeat of the Japanese amphibious force bound for Port Moresby in the Coral Sea, to the operations at Midway, Guadalcanal, Tarawa, Saipan, Leyte Gulf, the Philippine Sea, Okinawa and Iwo Jima.
• The length of time required to develop new capabilities. The time, effort and cost of reconstituting major capabilities and platforms—especially major warships and amphibious shipping—is much longer than that required to develop small littoral craft and to put them into production.
• The critical importance of land-based air power to sea control, especially in archipelagos that were avoided by naval carrier battlegroups due to the lack of sea room.
• The critical importance of sea control so as to use the ocean as a manoeuvre space for land forces.
• The critical importance of land forces for persistence and to seize and hold the vital terrain, especially ports and airfields as well as towns and major cities, logistical hubs and critical infrastructure.
• The need for a functioning institutional (administrative, structural) system for littoral and amphibious warfare and the development of a ‘archipelagic army’—one that is as comfortable conducting jungle and urban operations ashore as it is manoeuvring and striking from the sea, and providing sea and air denial capabilities.

While these lessons are enduring, there are as many changes as there are continuities in this operating environment. This means that the Australian Army must also deal with some fundamental contemporary changes and challenges.

The SWPA was a region fought over largely by ‘external’ powers in a period still dominated by colonialism. Now, this region is home to sovereign states and vibrant economies that reflect the nature of our modern world. For instance, it is estimated that by 2050 Indonesia will be the fourth largest economy in the world.^[xli] Never have bilateral and multilateral regional partnerships been more key. In an era of strategic competition, the most effective means of prevention of war is the maintenance of a regional military balance that creates the conditions for all states to exert their sovereignty, free from coercion. Army-to-army contact, engagement, exercises and confidence-building measures are essential for Australia and all like-minded states in the region.^[xlii] As 2020’s Army in Motion states:

[B]uilding relationships, capacity and resilience with other land forces… demonstrates credible and potent land power to deter adversaries … and to respond to disasters, crisis and conflict. This is critical for Australia’s ability to support Allies and partners in the region and our support to helping maintain their sovereignty.^[xliii]

Just as profound as changes to human geography in the region are the changes to our ‘technological geography’. These challenges are, in some ways, the same yet different. While a World War II digger would, for instance, step onto a modern landing craft and be completely comfortable with its layout, operations and configuration, the digital landscape he would encounter would be completely new. Modern navigation and communications systems, the use of satellite and infrared et al. would be foreign to any member of the 2nd AIF. Trying to absorb the use of modern autonomous systems, artificial intelligence, quantum computing, robotics, hypersonics and human-machine teaming would be entirely alien. Similarly, the pervasiveness of command, control, communications, computers (C4) and intelligence, surveillance and reconnaissance (C4ISR) capabilities would vex the average soldier of the 2nd AIF.

Another significant factor is the growth of military lethality and precision guided munitions, as well as the re-rise of A2AD technology in a return to the long-running friction between access and denial—that is, between offensive and defensive firepower.^[xliv] This latter point is demonstrated by the ever-increasing range of strike capabilities that expands reach and seemingly shrinks the previous benefits of geographical distance. Where once Australia was a far-off and ‘safe’ bastion, it is now within range of critical capabilities from the region’s major powers.

The move to a multi-polar strategic environment and the rise of major power competition means that in any widespread major conflict there will be an open contest in all domains. Access and use of key domains by any belligerent is not assured, and control of the air, sea, land, cyber and space may well be temporal. This new reality will require relearning some old lessons and adapting some new ones. The impact of surveillance, reconnaissance and targeting over very long ranges is, however, nothing new. In the Papuan campaign of 1942, for example, and especially the beachhead operations from September 1942 to January 1943, neither side had air superiority or sea control. 

At best, both sides were able to achieve temporal air control, but it was always contested. The lack of air control meant that neither side could achieve sea control, thus confining the campaign to a gruelling attrition style of operations: a land campaign in a maritime environment. Most significantly, the limitations of sea control on logistics for the Army limited force flow and constrained its ability to conduct combined arms operations.^[xlv] It took 17 plane-loads, for instance, to move just one troop of two 25-pounder artillery pieces to the beachheads area from Port Moresby, including only 306 rounds of ammunition per gun. It was also an operation limited by the atrocious weather.^[xlvi] For the Japanese, this lesson led to a focus on supporting and reinforcing their land forces through infiltration—small barges and littoral craft were the means for logistics and reinforcement and their eventual withdrawal. Such platforms proved effective as they were low signature, low cost, mobile and fast moving, and used distributed manoeuvre. While large-scale shipping access was important at the operational and strategic levels, tactical littoral manoeuvre and supply was dependent on small craft. This is a lesson not lost on contemporary military forces in the Indo-Pacific region, who have adapted concepts and force structures to respond to these enduring operational challenges.^[xlvii]

Leading this intellectual reconsideration of littoral manoeuvre and the character of operations in the modern Indo-Pacific operating environment is the US Marine Corps. The Marine Corps has introduced numerous innovative warfighting concepts and stood up new Marine Littoral Regiments to carry them out. Its focus is on peer-to-peer warfighting, predominantly in the Indo-Pacific.^[xlviii] At the same time, the United Kingdom’s Royal Marines and the Netherlands Marine Corps have introduced similar littoral warfighting concepts in recent years. The Royal Marines proposal employs two Littoral Response Groups: one based in Europe and the other in the Indo-Pacific. However, these are not problems for marine corps alone. The vast bulk of the fighting, amphibious, littoral and archipelagic operations in the Pacific War were conducted by armies (including the Australian Army) that had to adapt to, and adopt, the same or similar operational concepts. By 1945, the Australian Army had its own extant amphibious doctrine and tactics, techniques and procedures for archipelagic warfare.^[xlix]

A Ship Is a Fool to Fight a Fort

This primer concludes with one of the most fundamental operational changes between the Pacific campaigns of World War II and today, which relates to the role of long-range land-based A2AD systems. This development has and is reshaping how modern high-intensity warfare could potentially play out in the Indo-Pacific. Weapons range was a key factor in determining the commitment and use of tactics to exploit and manoeuvre in the littoral. In 1942 at Rabaul, Australian forces melted back into the jungle or went into captivity because the absence of Allied air and naval power left them at the mercy of the Japanese naval force and landing force. At Port Moresby the same year, Australian militia units waited patiently for the outcome of the battle of the Coral Sea as their fate hung in the balance. If the Allied naval forces were defeated, the land force’s weapons were completely outranged by an IJN task force comprising carrier aircraft, cruisers and destroyers. At Lae in 1943, the 9th Australian Division landed just over 12 miles outside of the main objective—just outside the range of Japanese artillery. At Tarawa, Okinawa, Iwo Jima and all the major amphibious landings later in the Pacific War, the IJA’s coastal defence batteries could only engage Allied ships at very limited ranges and its anti-aircraft defence was measured in a small number of miles. The anti-access battle was at sea and in the air, while the land forces’ area denial capabilities against air and naval forces were limited to the very close-in fight, and were almost always outranged and outgunned.

During World War II, air control provided sea control, while sea control allowed the manoeuvre of land forces to bypass the enemy or to strike at key points of one’s choosing. Now, the proliferation of long-range surface- to-air, surface-to-surface and land-based anti-ship missile systems have the potential to be much more decisive, reshaping the role of land forces in the integrated force. Land-based systems are generally lower cost than naval or air platforms, can be replaced and reconstituted more easily, and have greater persistence that can be measured in weeks, months and years, as opposed to minutes, hours or days.

The provision of highly mobile land-based A2AD systems is now an essential competent of an integrated force. It gives the joint force commander an exponentially expanded range of options. This is because land power now has the potential to provide a major contribution to sea denial/control on the surface of the ocean for the navy to operate, or to provide air denial/ control to allow access for air forces and/or the manoeuvre of land and naval assets. Land forces also now have the ability to provide highly distributed and networked mobile land-based forces capable of utilising camouflage, concealment and deception in highly complex archipelagic terrain. In the littorals and especially archipelagos, with their much higher concentrations of land area to water, this provides an expanded range of options to complicate intelligence, surveillance and targeting. In many respects, land systems provide an asymmetric advantage to major adversary fleet units that are optimised for naval and air attack and defence. If land forces are equipped with mobility on land and at sea, they can be quickly positioned and repositioned using infiltration methods. By employing autonomous systems, they also have the potential to generate mass at critical operational points at sea, in the air and on land.

In any war involving major powers that becomes protracted—and history shows us that attrition and protracted conflict are the norm among such powers—land-based systems are highly capable of reconstitution, are cost effective and are relatively easy to replace. Interlocking land-based A2AD systems, working in an integrated fashion with naval and air power, and supported by cyber and space capabilities, offer the foundation to any major denial campaign at the strategic and operational level of war, which will be critical to establishing temporary sea and air control to achieve operational effects. This is at the heart of the strategy outlined in the DSR. Thus, localised superiority in the archipelago is not dependent on air power or naval power to provide sea control. Rather, it is about localised superiority that can be provided from all domains. This includes enabling by land forces to create synchronised effects from key terrain.

In totality, mobile, low-detection land forces can deliver a distributed system of ‘mobile forts’ in the littorals and archipelagos that have the ability to open and provide access to air and naval forces. Perhaps, in the contemporary battle between access and anti-access, we may well need to (once again) learn from Admiral Horatio Nelson’s reported dictum that ‘a ship is a fool to fight a fort’^[l]—especially one that is low detection and is constantly on the move in complex archipelagic terrain.^[li]

About the Author

Professor Peter J Dean PhD SFHEAP has an extensive background in military and defence studies. He is the Director, Foreign Policy and Defence at the United States Studies Centre at the University of Sydney. Professor Dean was Co-Lead of the 2023 Defence Strategic Review (DSR) Secretariat where he served as senior advisor and principal author for the Independent Leads, His Excellency Professor the Hon. Stephen Smith and Air Chief Marshal Sir Angus Houston AK AC AFC (Retd). Previously he was the University of Western Australia’s (UWA) first Chair of Defence Studies and the inaugural director of the UWA Defence and Security Institute. Professor Dean has authored numerous books and articles on the US-Australian alliance, Australian defence policy and military operations.

Endnotes