Stand-in Manoeuvre in a Contested Littoral Environment

Introduction

This paper explores concepts being developed by the United States Marine Corps, UK Royal Marines and Royal Navy (including the US Concept for Stand-In Forces, and the British Commando Forces concept), in order to inform an Australian approach to stand-in manoeuvre in contested littoral environments. The paper first examines the challenges and implications of a contested littoral environment, identifying the need to operate in a distributed, low-profile, mobile, modular and sustained manner inside the weapon engagement zone (WEZ) of a beyond-peer adversary’s anti-access/area denial (A2AD) bubble, within contested littoral or archipelagic space, through phases of competition, pre-crisis shaping, crisis, conflict and transition. Having defined the environment and its implied mission requirements, the paper then evaluates relevant US and UK concepts against that environment, to identify features for the Australian Defence Force (ADF) to consider emulating, along with aspects that would require modifications for Australian conditions. Finally, the paper applies the analysis to a potential Australian operating concept for stand-in manoeuvre in contested littoral environments, suggesting that such a concept would need to maximise survivability for deployed forces, sustainability across multiple phases within a campaign, use of robotic or autonomous systems and human-machine teaming, multi-domain or cross-domain deterrence, and interoperability/interchangeability with AUKUS partners.

Part 1—A Daunting Environment

The problem facing AUKUS partners in the Indo-Pacific is complex and challenging. It requires balancing survivability against mission success for forward-deployed forces, along with trade-offs among stand-in forces, follow-on forces and reach-back capabilities, across multiple warfighting domains and campaign phases. Choices made now—on capability acquisition, capacity, force structure, task organisation, the use of artificial intelligence (AI) and robotic and autonomous systems, operating concepts and campaigning constructs—will affect future conflict in ways that may be decisive, though hard to foresee. The Royal Marines and United States Marine Corps have each developed concepts that address this problem in broadly similar ways, though with important differences. 

This paper explores AUKUS partners’ approaches, with the goal of deriving useful insights for Australian forces facing the same environment.

Contested Littoral Environments and A2AD

A contested littoral environment is that portion of an operational theatre where the tactical effects of air, land and maritime domains overlap, so that land-based weapon systems can engage sea-based platforms and vice versa. In these environments, littoral hydrography, bathymetry, topography, weather, climate and human activity interact with military operations in complex, non-linear ways. Littoral environments are bounded by military effects as much as by geography: as longer-range weapons and sensors are fielded, emerging and disruptive technologies are developed, or new warfighting domains materialise, the littoral environment expands accordingly.[1]

Over the last 15 years, the Indo-Pacific theatre has seen extraordinarily rapid proliferation in A2AD and counter-intervention capabilities, driven by heightened strategic competition between the United States and China. In China’s case, A2AD systems are designed to hold US forces at risk at extended range from contested coastlines, blockade regional US allies and partners, and deter or counter US intervention to support them.[2] Within an overall A2AD construct, anti-access systems impede movement into a contested area while area-denial systems hamper manoeuvre within that area. A2AD generates operational friction through overlapping, cumulative tactical effects which, in combination, delay and disrupt an adversary’s operations by imposing costs in time, materiel and human casualties that deter or deny access to a contested area.[3]

A2AD capabilities include anti-ship ballistic missiles (ASBMs); cruise missiles; integrated air and missile defence; maritime patrol aircraft and ships; submarines; strike aircraft; crewed and uncrewed stealth systems; space and counter-space weapons; cyber and electronic warfare systems; integrated intelligence, surveillance and reconnaissance (ISR); and command and control (C2) networks (often, in combination, referred to as C4ISR).[4] Autonomous systems including drones, loitering munitions, uncrewed surface vessels and autonomous underwater vehicles play increasingly important roles in A2AD, alongside traditional approaches such as mining of harbours, approaches and chokepoints, and close or distant blockades.[5] Containerised missile systems such as China’s YJ-18C anti-ship cruise missile can be deployed stealthily under cover of civil shipping, enabling covert insertion of A2AD capabilities into secondary contested areas distant from an adversary’s main territory.[6] A2AD may incorporate integrated cyber and electromagnetic activities (CEMA) to degrade, deceive or disrupt C4ISR, data networks and communications, including civilian systems. It may target offshore installations, as highlighted by the destruction of the NordStream pipeline in 2022, underlining an increased threat to seabed telecommunications or littoral resource extraction infrastructure.[7]

A2AD also involves the space domain: in 2021, the People’s Liberation Army (PLA) demonstrated a fractional orbital bombardment system employing a space-based hypersonic glide vehicle to engage targets at sea.[8] The same year, China’s BeiDou global navigation satellite system (GNSS) became fully operational, reducing Beijing’s reliance on the US military’s GPS, and making attacks on positioning, navigation and timing (PNT) satellites, as well as satellite communications (SATCOM), more likely—with severe implications for civilian economic activity and military C2 alike.[9]

Weapon Engagement Zones and Stand-in Forces

The WEZ in a contested littoral environment is the zone within which forces can be engaged by adversary weapon systems. It is bounded by weapon ranges, ISR detection and discrimination thresholds, and the ability of sensor-to-shooter networks and C4ISR systems to track, locate and prosecute targets.[10] In the Indo-Pacific, given the proliferation of PLA ballistic and cruise missiles and the militarisation of disputed features in the South China Sea, the WEZ extends hundreds to thousands of kilometres offshore and includes numerous islands, reefs, atolls and other archipelagic features, inhabited or otherwise. In practical terms, given the density of ISR and long-range weapons in a mature A2AD complex, any force element detected within the WEZ can be expected to be targeted, and is highly likely to be defeated or destroyed. 

Traditionally, US forces (and US allies such as Australia and the UK) have sought to enter an adversary’s WEZ only to accomplish specific time-limited tasks, with support from enabling assets arrayed to deceive, suppress or destroy adversary A2AD systems long enough to ‘shoot in’ friendly forces to their objectives and, if needed, extract them afterwards.[11] Several concepts—including the US Department of Defense Joint Operational Access Concept, the US Army’s Multi-Domain Manoeuvre, the US Navy’s Air-Sea Battle, and NATO concepts for Multi-Domain Operations—take this approach. The aim of these concepts is to open a window in time and space, temporarily suppressing adversary A2AD systems across a cleared corridor, to enable manoeuvre to the objective. In effect, these concepts seek to solve the problem of the WEZ by first suppressing adversary ISR and A2AD defences, then applying massed forces or effects, at high tempo, focused in time and space, to achieve objectives at acceptable cost. 

By the 2010s it was becoming apparent that—at least for a portion of the force—the notion of selectively entering an adversary’s WEZ only after suppressing it, and then returning to sanctuary, was unworkable. A writer in the US Naval Institute’s Proceedings journal noted in 2011: 

[S]ince the end of the Cold War, the United States has entered the adversary’s WEZ selectively, but that era is coming to an end. As adversaries’ weapons envelopes expand, the U.S. military … needs to embrace life within the WEZ.[12]

Forces that can survive and operate inside an adversary’s WEZ for protracted periods are designated as ‘stand-in forces’ (SIF) to distinguish them from those that operate from safe havens outside the WEZ, entering only for specific tasks and with supporting enablers. ‘Life in the WEZ’ therefore implies the development of capable and survivable SIF able to communicate and operate in a high-threat, CEMA-denied environment. 

Implications for Australia

Australia’s formal adoption of a maritime strategy in 2013 led to the development of ADF capabilities for ‘joint archipelagic manoeuvre’. This approach recognised the increasing range and density of A2AD in Australia’s region, the complex archipelagic nature of the operating environment, the role of land-based systems (and hence, land forces) in maritime campaigning, and the need to ‘exert persistent control over population centres, forward base locations and other key terrain that contributes to the securing of maritime transit lanes’.[13] This concept, though acknowledging the survivability challenge of ‘living in the WEZ’, assumed Australia would field a: 

medium weight army [with] sufficient combat weight and highly survivable land based capabilities [to] contribute to sea and air control bubbles adjacent to key strategic maritime choke points [and] also provide a range of credible options for Government for other contingencies such as stabilisation missions in the crowded, connected urban (and peri-urban) littoral.[14] 

In effect, the concept envisioned an updated version of Second World War ‘island-hopping’ campaigns in which land forces would seize bases to enable application of naval and air power through archipelagic or littoral manoeuvre. This approach assumed that an Australian joint force, ideally operating in concert with allies and partners, could suppress adversary capabilities and so enable persistent presence and manoeuvre at scale, in a relatively overt manner, inside or on the edge of an enemy WEZ. The Australian Amphibious Force (AAF) and Joint Pre-Landing Force (JPLF) as they exist today, including manoeuvre elements and enablers from across the ADF, reflect this thinking.[15]

But in the decade since the adoption of Australia’s maritime strategy, two factors have undermined several of its key assumptions. Externally, the extremely rapid proliferation of adversary A2AD systems with longer range, greater lethality and enhanced sensors has continued to accelerate even beyond what was anticipated a decade ago, calling into question the survivability of any force element that operates overtly, concentrates in time and space, relies on external resupply and maintenance, or masses where it can be detected and killed. Internally, the Australian Government’s decision, in National Defence: Defence Strategic Review 2023 (DSR 2023), to radically reduce the number of protected mobility systems planned for acquisition under Project Land 400 Phase 3 substantially invalidates the assumption of a medium-weight ADF joint force with ‘sufficient combat weight and survivable capabilities’ to execute the government’s own maritime strategy.[16] While it is, unfortunately, not unusual for Australian governments to adopt strategies which they subsequently fail to resource, this combination of factors makes it especially urgent for the ADF (and Army in particular) to update its operating concepts for stand-in manoeuvre in contested littoral environments.

Essential Features of an Australian Stand-in Manoeuvre Concept

As this analysis suggests, in order to be viable, an ADF stand-in manoeuvre concept would need the following key characteristics:

• Distributed. Forces will need to disperse physically to avoid destruction, while still being able to mass effects, strike at range, and draw upon follow-on forces and reach-back capabilities to destroy targets and seize or hold objectives.
   
• Low profile. To survive, force elements will need to maintain a stealthy profile, remaining below adversary ISR detection/discrimination thresholds. In combination with distributed operations, this will invoke a ‘dispersion dilemma’ whereby forces that physically disperse must then communicate electronically, thereby risking detection and subsequent destruction.
   
• Modular. Unit and task organisations, logistic support, mobility assets and key equipment will need to be modular, to enable forces rapidly to aggregate and disaggregate fires and effects throughout a disaggregated battlespace. Greater modularity, interchangeability among force elements, and tactical self-sufficiency will also reduce the requirement to communicate, relieving (to some extent) the dispersion dilemma.
   
• Mobile. Distributed modular forces in littoral or archipelagic battlespace will be at risk of being isolated, fixed and destroyed in detail unless they remain mobile. Mobility in this sense implies the ability both to enter contested littoral environments from outside, and to manoeuvre within contested space. 
   
• Sustainable. Forces ‘living in the WEZ’ need to be sustainable across critical classes of supply, maintenance and transportation for protracted periods while remaining undetected. This implies self-sufficiency, pre-campaign operational preparation of the environment (OPE), and a light logistic tail.
   
• Survivable. SIF will need to be survivable against a range of adversary weapon systems and manoeuvre assets inside the WEZ, ideally by remaining undetected and hence untargeted but, in a critical subset of cases, through hardened installations, protected mobility and close-in defences.
   
• CEMA resilient. Forces in the WEZ will face intense disruption and degradation efforts from adversary CEMA. Cyberattack, degradation of radio, SATCOM and GPS, and loss of fibre-optic links will hamper C2 and increase detection risk. Forces must be resilient to CEMA disruption while possessing capabilities for cyber and electronic deception, to dissipate integrated enemy CEMA.
   
• Beyond-peer relevant. In contested littoral space, Australian forces will almost certainly face a beyond-peer adversary—larger, more capable and more technically advanced than the ADF in some key areas. As the underdog, ADF elements will need to optimise for delay, disruption and cost imposition, trading space for time while inflicting damage to deter further aggression.
   
• Multi-phase. To deter, delay, disrupt and damage an aggressor, stand-in manoeuvre must be effective across multiple campaigning phases, from competition through pre-crisis shaping, crisis, conflict and transition. Forces must be able to transition in an agile manner among phases as a campaign develops.
   
• Multi/cross-domain. Finally, stand-in manoeuvre needs to be effective across multiple domains (land, sea, air, space, cyber and the electromagnetic spectrum). In addition, cross-domain coercion (applying assets from one domain for leverage in another) and hybrid warfare (operating across a spectrum of military and non-military measures to achieve campaign goals) remain relevant to stand-in manoeuvre in contested littoral space.

Some or all of these elements are already present in Australian concepts, including Adaptive Campaigning, Joint Archipelagic Manoeuvre and Accelerated Warfare, and the foregoing list is not intended to supplant these. Rather, it offers a template against which partner concepts can be evaluated, given key requirements for ADF stand-in manoeuvre. The next section applies this template to two of the most relevant of these partner concepts: the US Marine Corps Concept for Stand-In Forces, and the Royal Marines Commando Force concept.

Part 2—Comparative Analysis—AUKUS Partners’ Concepts

USMC Concept for Stand-In Forces

Since 2020, the United States Marine Corps (USMC), under its Force Design 2030 program, has been developing a suite of concepts, capabilities, organisations and doctrine to enable Marines to survive and operate in the WEZ, as part of a broader reorientation towards great-power competition in the Indo-Pacific.[17] Though each USMC concept has much to offer the Australian Army, one in particular, the Concept for Stand-In Forces, is directly relevant to stand-in manoeuvre in contested littoral environments. In addition, the USMC in 2020 disbanded its three tank battalions, reducing protected mobility and optimising for stealth and distributed operations within a lighter force.[18] This decision offers lessons for an Australian Army whose protected mobility under Land 400 Phase 3 has just been dramatically reduced through DSR 2023.

The USMC concept defines SIF as: 

small but lethal, low signature, mobile, relatively simple to maintain and sustain forces designed to operate across the competition continuum within a contested area as the leading edge of a maritime defense-in-depth in order to intentionally disrupt the plans of a potential or actual adversary. Depending on the situation, stand-in forces are composed of elements from the Marine Corps, Navy, Coast Guard, special operations forces, interagency, and allies and partners.[19] 

Under this concept, SIF will be positioned in the WEZ, working with allies and partners. As stated in USMC Force Design 2030: 

[A]s the eyes and ears of the fleet and joint force, [SIF] have the enduring tasks of conducting reconnaissance and counter-reconnaissance for [a] naval campaign at every point on the competition continuum. If necessary, these forces will conduct sea denial in designated areas in support of the naval campaign.[20] 

SIF are postured to delay, disrupt and damage an adversary using organic weapon systems, but will also form nodes within ‘naval and joint kill webs, helping to bring all-domain effects to bear when needed. In doing so, Marines will extend the reach of the fleet and joint force from inside contested areas’.[21]

In this concept, SIF form the forward land elements of a multi-domain ISR network, seeking to identify adversary activity, building understanding of enemy capabilities, and helping the joint force to make sense of the environment (in physical, human and network terms). SIF operate from within an adversary’s WEZ, conducting multi-domain counter-reconnaissance during the competition and crisis stages of a campaign. In the conflict phase, they ‘remain forward in the contested area alongside allies and partners to support naval and joint campaigning’.[22] 

The Stand-In Forces Concept depicts an environment characterised by proliferation of a ‘mature precision strike regime’ in which adversaries of all kinds ‘are demonstrating the ability to accurately sense the battlespace in multiple domains and rapidly strike’ while continually improving ISR and targeting. One conclusion is that SIF must establish persistent presence in the WEZ, and that failure to do so would make it extremely difficult ‘to re-establish access from strategic distance … Trying to gain access to a denied area from the outside is a symmetrical response to a counter-intervention approach, which should be avoided’.[23] As discussed below, this aspect—the need to gain access to a denied WEZ from outside, rather than being pre-positioned inside the WEZ at the outset of a conflict—is a significant difference between the USMC concept and the Royal Marines Commando Force concept.

Figure 1. A Navy Marine Expeditionary Ship Interdiction System (NMESIS) launcher, 2021. (Source: U.S. Marine Corps)

The theory of success for SIF, across multiple campaign phases, is that SIF deter adversaries during competition by ‘establishing the forward edge of a partnered maritime defense-in-depth that denies the adversary freedom of action’. They operate by ‘gaining and maintaining contact (establishing target custody and identifying the potential adversary’s sensors) below the threshold of violence’, providing early warning of adversary action, disrupting it with organic weapons, or cueing follow-on forces and joint assets as part of a stealthy, forward-deployed kill web. If a crisis escalates into conflict, SIF conduct sea denial, focused on maritime chokepoints, again using a combination of organic and reach-back capabilities. 

In effect, SIF represent the contact layer of a maritime cost-imposition strategy that slows adversaries and requires them to commit larger forces, across a wider area, with greater risk and more supporting assets. An adversary surface action group attempting passage of a contested littoral chokepoint or archipelago, for example, would need to allocate more time and greater resources, and accept the possibility of heavier losses, in the face of forward-deployed SIF. In this way:

SIF become an operational problem an enemy must address to achieve its goals. SIF impose costs on the enemy by presenting operationally relevant capabilities that cannot be ignored, even as their low signature, high mobility, dispersion, and use of deception make them difficult for an enemy to find and target. Their small footprint and focus on partnership make SIF less burdensome on the host nation than larger U.S. formations.[24] 

(Note the assumption that SIF are declared to a host nation, rather than acting in a clandestine/covert manner in contested territory.) 

The concept seeks to deploy the smallest possible force forward, linked into a joint sensor-to-effector network, thus minimising the at-risk force and reducing logistic requirements. It envisions a layered deployment in zones, with the forward-most zone comprising autonomous systems, backed by a layer of human-machine teams to ‘control the forward elements, operate an additional layer of manned and unmanned sensors, integrate operations with allies and partners, and … provide direction and support to unmanned systems as they cycle forward’.[25] A rearward zone includes major weapon systems such as missile batteries, with logistics and C2 elements. The SIF concept assumes that anything ‘requiring significant sustainment or manpower support will ideally be postured afloat and/or ashore outside the contested area to minimize the footprint and signature inside the contested area’.[26] 

Beyond the force-multiplier aspect of their ability to draw on a distributed kill web, SIF achieve an awareness-multiplier effect by operating with host nation partners, conducting security assistance and joint exercises to build relationships and develop awareness of normality patterns, enabling them better to detect adversary hybrid or grey-zone activity. This preference for operating ‘declared’ to local partners distinguishes SIF from special operations forces or clandestine teams.[27] 

During major combat, SIF are envisioned as tipping and cueing a larger joint force positioned outside the WEZ (or beyond the contested area altogether) so that, as SIF disrupt and delay an adversary, joint forces can exploit windows of adversary vulnerability to enter the contested area. This tactic forms a series of ‘pulses of combat power’ in which manoeuvre into the WEZ is enabled by persistent SIF presence, feeding sensor data and intelligence to a joint force postured to exploit vulnerabilities, in an archipelagic version of recon-pull manoeuvre.[28] In effect, SIF fight in the manner of a traditional covering force, setting favourable conditions for manoeuvre by naval and joint forces.

In terms of survivability, SIF are ‘designed to survive inside a contested area through the application of a “hard to find—hard to kill” approach’ through signature management, remaining mobile, dispersing, and defeating adversary sensors. Deception, using physical decoys and cyber or electronic emitters to offer multiple ‘false positives’ to sensors, serves to dissipate adversary countermeasures, while providing sufficient background clutter for SIF to merge into the environment. This is an indirect protection approach, emphasising the outer layers of the ‘survivability onion’ (‘don’t be there, don’t be seen, don’t be hit’) rather than direct protection (‘survive a hit’). Modularity, dispersion and stealth thus play critical roles for lightly protected SIF unable to rely on hardened installations or protected mobility.

Royal Marines Commando Force Concept

Like the USMC, the Royal Marines (RM) are engaged in a strategic transformation. This was in response to decades of land-based counterinsurgency and irregular warfare. In 2003, RM Commandos were forced to set aside an earlier transformation effort in order to organise and operate in a broadly similar manner to the British Army battalions alongside which they rotated through Iraq and Afghanistan. Commencing in 2018, however, increasing great-power competition and the crucial importance of maritime and littoral space for a global maritime power like the United Kingdom prompted the RM, as part of a broader Royal Navy effort, to refocus on amphibious warfare, raiding and special operations. In pursuing this transformation, the RM recognised that while the current Commandos could successfully deliver raiding and special operations, there was a need to reinforce, distribute and modernise these capabilities. The goal was to give the amphibious commander greater flexibility to choose raiding or special operations, and to execute these at smaller (and thus, against today’s threat, more survivable) scales.[29] The result was the Commando Force (CF) concept.

Like the USMC concept for SIF, the CF concept involves small, stealthy, mobile, lethal force elements that can enter and operate within an adversary’s WEZ, supporting fleet operations and projecting land power as a Littoral Response Group (LRG). The LRG sits within the larger Royal Navy Littoral Strike Group (LSG) and integrates its effects into a distributed kill web in the form of the Naval Strike Network (NSN).[30] 

The goal is ‘a Commando Force that is more sophisticated, more lethal, more persistently forward and delivering special operations’.[31] The concept thus seeks to provide the one-star amphibious commander with choices beyond current norms. It allows the amphibious group to easily split into two vectors of military opportunity, with each as capable as the overall amphibious group but at reduced scale (and hence reduced signature and improved survivability). This also seeks to create resilience and redundancy. The ability to split and distribute the formation for tactical advantage creates opportunity to deploy task-organised, combined-arms increments of the LSG into contested areas as persistent-presence LRGs. Thus, in effect, the LRGs form an integral part of the Royal Navy’s formation-scale amphibious group, but offer the ancillary benefit of persistent presence or SIF action as required.

The CF concept has not been published in an unclassified version, unlike the USMC concept for SIF. However, it follows a similar logic: the need for small, modular, networked force elements that leverage autonomous systems and a wider kill web to operate in contested littoral space in a stealthy manner. CF seek to be agile across multiple domains, including the electromagnetic spectrum and cyberspace, drawing on joint and coalition capabilities for lethality and survivability. 

The CF organisational structure reflects this approach, with each of the two LRGs operating as RM Commando (i.e., battalion) sized organisations within the LSG, alongside Royal Navy amphibious ships, surface combatants, submarines and aviation elements, and able to operate in concert with a carrier strike group (CSG) built around one of the UK’s two aircraft carriers. The LSG is a joint one-star commanded grouping optimised for crisis response and joint theatre entry, either independently or to enable massing of other forces. Each LRG is assigned three CF strike company groups (SCGs) plus supporting elements from the RM, along with specialists from the British Army. The SCG, at approximately a reinforced company group in size, is the heart of the concept. It is structured to operate in a stealthy, distributed manner, organised into nine teams, each with its own organic mobility, fires and communications, specialised for specific combat or combat support tasks, and able to aggregate and disaggregate as needed to mass fires and effects. Each LRG maintains one SCG persistently forward-deployed, with another held at readiness afloat, on land or at a home base. Aviation, medical, engineers, reconnaissance and ship-to-shore connectors complement the SCG, forming a land component optimised to support joint littoral manoeuvre by the LSG commander. 

Figure 2. Landing Craft from HMS Albion during an exercise. (Source: U.K. Ministry of Defence)

SCGs work with forward-deployed marine liaison assessment teams (MLATs) and a joint interagency cell cooperating with regional allies and partners, along with information exploitation and outreach teams conducting military information support operations, and electronic warfare/signals intelligence teams. Each SCG includes logistics and medical capabilities, fires, organic mobility, engineering assets, and joint effects teams. An SCG can support or operate alongside UK Special Forces (UKSF) in strike, reconnaissance and other special operations while conducting security assistance and ISR in a theatre. This enables a distributed, multi-domain, special operations-capable land component that can operate in a warfighting scenario inside or on the edge of an adversary’s WEZ, while retaining utility for missions such as humanitarian and disaster relief, non-combatant evacuation, and defence engagement.

During competition, CF may conduct ISR/counter-ISR and shaping operations, as well as training and security assistance with regional partners. As a crisis develops, they may assist in denying, securing or reinforcing chokepoints to enable an LSG or CSG to manoeuvre in contested littoral or archipelagic space. During conflict, they act as eyes and ears for the joint force to enable the NSN or a coalition kill web to conduct find/strike or deny/defend missions, and disrupt or disable adversary A2AD systems to facilitate follow-on forces or enable massing of other elements. They can also conduct raiding or strike operations independently or with UKSF or allied forces.

Like USMC SIF, RM CF expect to make extensive use of robotic and autonomous systems and human-machine teaming to minimise human force elements at risk inside an enemy’s WEZ, via the NSN and the Royal Navy’s broader autonomous systems initiative.[32] They expect to operate in a distributed, low-profile manner, relying primarily on indirect rather than direct protection for survivability. Like USMC SIF, RM SCGs possess hardened vehicles for protected mobility, along with direct and indirect fire weapons and ship-to-shore connectors such as landing craft and helicopters. Unlike USMC SIF—which are presumed to already be present, operating concealed inside an adversary’s A2AD bubble (but below its detection/discrimination threshold) before the onset of conflict—CF recognise that they may need to initially operate from outside an adversary’s A2AD bubble, and therefore may have to penetrate contested space, including entering an adversary’s WEZ, in a joint theatre entry operation. This is not to suggest that the RM concept underplays the risk of theatre entry, or deliberately seeks to invoke a requirement to ‘pierce the bubble’ of an adversary A2AD system. Indeed, one key goal is for routine LRG deployments to create persistent presence in contested areas so as to avoid the requirement for a full-blown theatre entry. Rather than seek a theatre entry scenario, the RM concept represents a recognition that—like it or not—LRGs will need capabilities to do so if required.

This requirement for a potential theatre entry, along with the need to mass for offensive operations and the explicit special operations tasking of CF, represent some of the key differences between the CF and SIF concepts. Another is scale: RM CF, even augmented by British Army units and allies, are still significantly smaller (at roughly 4,400 personnel) than the multiple brigade-sized marine littoral regiments envisaged under the USMC SIF concept. At the same time, the LRGs need to cover multiple environments, with LRG (North) operating in a NATO- and Europe-facing posture (thus likely involving mountain and cold-weather warfare) while LRG (South) is Indo-Pacific facing and expected to routinely engage in tropical and desert warfare. An environmental split between the two LRGs is not part of the CF concept, which recognises that over-specialisation or ‘streaming’ each of the LRGs for one specific environment reduces flexibility. Rather, both LRGs expect—as increments of the globally deployable LSG—to fight in any environment, preparing accordingly. 

Evaluation of AUKUS Partners’ Concepts

The criteria established in Part 1 enable an evaluation of the key features of the SIF and Commando Force concepts. These can be summarised as follows:

• Distributed. Both concepts rely on distributed operations, dispersing force elements across a wide area in small teams that cooperate by massing effects and fires rather than physically co-locating. In both concepts, forces make extensive use of robotic and autonomous systems and human-machine teaming in order to generate the greatest possible effect while placing the smallest possible number of humans in harm’s way. As noted earlier, the distributed aspect of both concepts invokes a dispersion dilemma—to survive in the WEZ, units need to disperse, but at the same time, in order to mass their effects, distributed force elements need to communicate with each other and interact with a broader kill web, creating risk of electronic detection and targeting. This is a common feature of both concepts, and also an issue that would apply to Australia’s JPLF and AAF under similar circumstances. In Australian doctrine, distributed manoeuvre: 

seeks to close with and destroy the enemy without presenting a targetable mass. Importantly, it seeks to harness the synergies that come from combining precision joint fires and manoeuvre elements into small, agile combined arms teams that ‘burrow’ into complex terrain to detect, identify and kill or capture the enemy with precision, discrimination and an understanding of the potential second and third order consequences that may arise.[33] 

This aligns closely with the US and UK concepts for stand-in manoeuvre.

• Low profile. The USMC SIF concept relies on a ‘hard to find, hard to kill’ indirect protection model, with small teams operating stealthily from pre-selected locations. It assumes that SIF are already present inside the WEZ at the outset of conflict, and hence that there is no requirement to penetrate the WEZ from outside in the face of adversary A2AD systems. In contrast, the CF concept assumes that some elements of the LRG (indicatively, one SCG) will be persistently forward-deployed in the theatre, with the remainder afloat or in a land base. Thus, while some parts of the CF may be inside an adversary’s WEZ at the outset, others may need to penetrate a contested area against A2AD systems, running the risk of detection and destruction as a result. This imposes a requirement (though, as noted, not a preference) for joint theatre entry on CF. The UK concept thus is closer to the circumstances Australia might face, in that the JPLF might be forward-deployed conducting ISR and counter-reconnaissance ahead of the main force and thus be inside the WEZ from the outset, whereas the main landing force would need to conduct a joint theatre entry—and possibly an opposed transit in amphibious and sealift shipping—before engaging the adversary. Also of note, both concepts assume that SIF/CF are ‘declared’ to the host nation, which brings benefits for situational awareness but also imposes some vulnerability to disclosure by third parties. In Australia’s case, force elements from Special Operations Command (SOCOMD) and the JPLF may or may not be declared to host nations depending on the circumstances.
   
• Modular. Both concepts envisage a modular force structure, in which SIF/CF teams are self-supporting interchangeable squad/section-sized teams that can aggregate and disaggregate fires, forces and effects. The USMC SIF concept is somewhat more modular than the UK approach in that it includes multiple functionally and organisationally interchangeable teams performing multiple combat and combat support tasks (albeit deployed in three distinct layered zones and with different characteristics in each). The UK CF concept currently envisages each team within the strike company performing different roles with specialised equipment, but this is an evolutionary stepping-stone towards an optimal future organisation where every team is interchangeable and equally capable across all tactical functions. In Australia’s case, the JPLF (and any SOCOMD elements committed) would probably operate similarly to CF, while the main AAF and follow-on forces would be organised similarly to SIF.
   
• Mobile. As noted, the USMC concept assumes SIF are already in the WEZ, and emphasises stealth and dispersion rather than mobility. Some elements have the multi-modal organic mobility to move from one island to another in a protected manner, while others would be vulnerable to being fixed in place if an adversary were to destroy (or simply force further offshore) the sealift and ship-to-shore assets they depend on. In the UK concept, all elements of the CF have organic mobility on land, but only some—primarily, specialised ISR and boat teams—have organic seaborne mobility. The RM concept sees specialist boat squadrons that (like the strike teams) are cross-functional and distributable as smaller echelons, retaining potency across the tactical functions down to each individual boat, with ‘dumb’ landing craft a thing of the past. These boat squadrons will be allocated to manoeuvre, ISR or strike missions as needed, either task-organised with strike teams embarked or as independent fighting elements in their own right.[34] In the Australian case, helicopters and landing craft provide ship-to-shore mobility but the force, once landed, has less organic mobility (and significantly less protected mobility) than UK CF or USMC SIF. Thus, Australian forces run the risk of being fixed in place if supporting sealift and amphibious assets are disrupted.
   
• Sustainable. Both the UK and US concepts recognise logistic sustainability (particularly resupply and maintenance) as critical concerns. As in the dispersion dilemma already noted, there is a sustainability trade-off for distributed, stealthy forces. Forces that rely on frequent resupply can be lighter and more organically mobile, but they run the risk of being compromised by resupply assets and destroyed in position, whereas those that instead rely on cached supplies or attempt to carry more in first- or second-line transport are less mobile and less stealthy due to larger loads and fixed installations. Host-nation support (where forces are declared) and pre-conflict operational preparation of the battlespace are only a partial solution to this problem. 
   
• Survivable. UK CF are arguably most vulnerable when entering or transiting the WEZ, either airborne or afloat, in assets belonging to the LSG. Once ashore, SCGs have a mix of mobility and protection assets, and can be expected to disperse, hide and harden their positions in order to improve survivability. The USMC SIF concept does not directly address this problem since its ‘hard to find, hard to kill’ approach emphasises stealth and dispersion. However, in both cases, the broader kill web is likely to play a critical role in the force’s survival, as long as forward-deployed elements can sense, communicate, and pass targeting information to joint fires assets. In Australia’s case, reliance on joint fires would be even more significant since the JPLF lacks organic protected mobility and the AAF would need to call for air and maritime fire support.
   
• CEMA resilient. This reliance on a distributed joint fires network makes resilience to CEMA attack an extremely important aspect of all three AUKUS partners’ concepts. Should an adversary successfully disrupt or deny sensor systems, C4ISR networks, and/or space-based PNT and navigation assets, forward-deployed forces would be unable to call for joint fires and would be correspondingly vulnerable to defeat in detail. Minimising emissions, signature management, use of civilian systems where authorised, and employing low-power/no-power systems will be necessary wherever possible. Likewise, deception—seeding a contested littoral environment with decoys, emitters and simulated forces—is recognised as an important aspect in both the UK and US concepts, and would be equally important for Australian forces. 
   
• Beyond-peer relevant. While the US, arguably, does not face a beyond-peer adversary, both Australia and the UK would do so if operating outside an alliance framework. Indeed, even when operating together all three AUKUS partners might face a locally or temporarily superior adversary. There is an implicit trade-off between holding forces back from a WEZ, and running the risk of losing any assets committed. The USMC construct of pre-deployed forces already ‘living in the WEZ’ and engaged in continuous shaping operations addresses this to some extent, but only if such forces can successfully avoid detection. UK CF and Australian forces (with the possible exception of SOCOMD and some JPLF assets) would potentially need to enter the WEZ after the outbreak of conflict, and could therefore suffer significant losses. Moreover, since both the UK and Australia have very limited numbers of sealift assets and amphibious shipping, loss of a major surface platform could have strategic implications beyond the immediate campaign.
   
• Multi-phase. Both the US and UK concepts envisage operations across the full competition continuum, including in pre-conflict shaping, crisis and conflict. The USMC SIF concept optimises for combat in the Indo-Pacific during overt conflict, whereas the UK requires the LSG and supporting LRGs to be relevant across the full range of military operations. In Australia’s case, the AAF is required ‘to employ a landing force of up to battlegroup strength over the spectrum of operations, from the provision of humanitarian assistance and disaster relief to high-end warfighting’ and—after the JPLF has secured an area of operations—conducting strategic shaping; humanitarian operations; non-combatant evacuation, peace and stability operations; and joint combat.[35] Accordingly, the UK approach is likely to have broad utility for Australian forces, noting that neither the UK nor Australia has the force size to conduct multiple missions simultaneously, at scale, across the continuum of competition.
   
• Multi/cross-domain. Both the UK and US concepts emphasise the need for multi-domain manoeuvre in contested littoral environments. The ability to draw on assets and effects from one domain and apply them in another is inherent in the NSN and multi-domain kill web constructs, as is the notion of deterring an adversary’s cross-domain coercion in hybrid and grey-zone operations. The UK concept is somewhat more explicit about this aspect, but this is arguably because US planners tend to take cross-domain and multi-domain manoeuvre for granted. In Australia’s case, deterring adversary aggression would certainly require multi/cross-domain activity, often including alliance and partner assets such as space, cyber and ISR assets. Of note, one potential trade-off for all three AUKUS partners would exist between the need for stealth and concealment as part of a ‘hard to see, hard to kill’ survivability approach, and the need to deter adversary aggression by telegraphing actual or potential presence in a given contested area. 

Part 3—Adapting AUKUS Concepts for Australian Conditions

Based on the foregoing analysis, it is clear that both the USMC and RM concepts have much to offer Australia, as the ADF considers the need for an enhanced capability for stand-in manoeuvre in contested littoral environments. Since 2013, the ADF has expended considerable effort in the rapid development of an Australian amphibious capability to be reckoned with.[36] At the same time, however, the environment is rapidly becoming considerably more challenging as US-China competition heightens across the Indo-Pacific, in Australia’s region of primary area of strategic military interest, ‘encompassing the north-eastern Indian Ocean through maritime Southeast Asia into the Pacific’ and including Australia’s northern approaches.[37] At the same time, regional nations and even some non-state actors are acquiring A2AD systems that leverage distributed, low-profile, improvised and advanced technologies in ways that increase the threat even without peer or beyond-peer adversaries. As new A2AD and counter-intervention systems are fielded across this region, and as tensions increase around specific flashpoints including the Taiwan Strait, Korean Peninsula, Japanese outer islands and South China Sea, the ability to avoid stand-in manoeuvre—to stay out of an adversary’s increasingly capable WEZ—is rapidly evaporating. 

It is beyond the scope of this paper to develop a detailed Australian concept for stand-in manoeuvre. However, in outline, it is clear that such a concept would need to emphasise the four main criteria discussed above: survivability for deployed forces, sustainability across multiple phases in a protracted campaign, multi-domain or cross-domain deterrence, and interoperability/interchangeability with AUKUS partners. 

Given the limited size of the AAF, the available number of amphibious ships, and the government’s decision in the DSR 2023 to reduce Army’s protected mobility to a single battlegroup, any failure in survivability of the deployed force could have significant strategic implications for Australia. Loss of a Canberra-class landing helicopter dock (LHD), destruction of an Army battlegroup, or loss of a number of ship-to-shore connectors such as landing craft and helicopters, could cripple Australia’s power-projection capability and render the nation dependent on allies for a rescue that might never come, if partners were simultaneously committed to their own fights. Given the lack of force size and protected mobility, a distributed, stealthy, modular approach—fielding company-sized or smaller combat groups that follow an indirect protection and ‘hard to see, hard to kill’ model—clearly makes sense. While some SOCOMD elements and parts of the JPLF could conceivably already be pre-deployed in an adversary WEZ before the outbreak of a conflict, the broader AAF and follow-on forces will most likely need to penetrate an adversary A2AD bubble (and indeed to create their own A2AD bubble) in order to seize or reinforce contested points. For this reason, and because the forces are closer in size, the UK RM Commando Force concept offers a useful starting point in this regard. 

Multi-phase sustainability through a protracted campaign will be a key requirement for Australia, as for the other AUKUS partners. The dispersion dilemma, the trade-off between forward-deployed and on-call logistic support, the risk of compromising concealed forces through too-frequent resupply, and the need for medical support and casualty evacuation are all aspects of sustainability that will need significant analysis, ideally through wargaming and exercising alongside AUKUS partners. As both the US and UK concepts note, trusted relationships with regional partners will be an important force multiplier, suggesting that strategic shaping and operational preparation of the environment will be particularly important pre-conflict elements, in order to set the conditions for subsequent campaign success.

Of course, far better than engaging in conflict would be to successfully deter an aggressor through a demonstrated ability to impose costs, or through pre-emptively securing contested areas. Enhancing short-term deterrence is thus also important in the AUKUS context, since capabilities such as the conventionally armed, nuclear-powered submarines to be acquired under AUKUS will take such a long time to implement, even as regional competition rises rapidly. Beyond AUKUS, working with partners such as Japan, the Republic of Korea and NATO nations with capable amphibious forces can enhance deterrence, as can cooperation with like-minded regional powers. Demonstrating the ability to conduct stand-in manoeuvre in contested littoral areas, ideally but not necessarily in concert with partners, could be enhanced through defence cooperation and exercise activities.

Clearly, the three AUKUS partners already possess a high degree of interoperability across a range of capabilities including amphibious operations. The Australian government’s move away from the protected mobility needed for a medium-weight Army significantly reduces Army’s ability to operate in a high-threat land-centric environment alongside the US Army, suggesting that a focus on interoperability with the USMC and UK RM (along with other British Army elements of equivalent mobility and protection to the Australian Army) may make more sense.

More broadly, the similarity of concepts among the three AUKUS partners—along with compatible capabilities held by other NATO countries and regional partners such as Singapore—offers opportunity to craft a coalition capability for joint stand-in manoeuvre in contested littoral environments. The UK CF concept, for example, is explicitly set within a coalition context. The beyond-peer capability offered by British LRGs under the CF concept lies in the coalition contribution that such a force could make to combined joint littoral manoeuvre, and the same potential would be offered by an equivalent Australian concept. Thus, the opportunity here goes well beyond mere interoperability, towards a deterrent capability of significant strategic utility for Australia as well as for other AUKUS partners.

Conclusion

This paper has explored two concepts currently being developed by the United States Marine Corps, UK Royal Marines and Royal Navy (the US Concept for Stand-In Forces, and the British Commando Forces concept) to inform an Australian approach to stand-in manoeuvre in contested littoral environments. As the paper has identified, an increasingly daunting set of A2AD and counter-intervention capabilities have proliferated within the Indo-Pacific over the last 15 years as a result of increasing strategic competition between the United States and China. The challenges inherent in a contested littoral environment emphasise the need to operate in a distributed, low-profile, mobile, modular and sustained manner inside the WEZ of a beyond-peer adversary’s A2AD bubble, within contested littoral or archipelagic space, through multiple phases along a competition continuum including pre-crisis shaping, crisis, conflict and transition. Both the US and UK concepts offer important features for the Australian Army to consider emulating, and aspects on which to improve, or which need modifying for Australia’s specific circumstances. This suggests that a future Australian operating concept for stand-in manoeuvre in a contested littoral environment should seek to maximise survivability for deployed forces, sustainability across multiple phases in a protracted campaign, multi-domain or cross-domain deterrence, and interoperability/interchangeability with AUKUS partners. It could also offer a beyond-peer coalition contribution which, once fully developed, would carry significantly enhanced deterrence for a potential adversary.

About the Author

Dr David Kilcullen is Professor of International and Political Studies at UNSW Canberra and CEO of the analysis firm Cordillera Applications Group. Professor Kilcullen is a theorist and practitioner of guerrilla and unconventional warfare, counterinsurgency and counterterrorism, with operational experience over 25 years with the Australian and U.S. governments as an infantry officer, intelligence analyst, policy adviser and diplomat. He served in Iraq as senior counterinsurgency advisor to Multinational Force—Iraq, then as senior counterterrorism advisor to Secretary of State Condoleezza Rice, deploying to Afghanistan, Pakistan, Somalia, Libya and Colombia. He is the author of eight books and numerous scholarly papers on terrorism, insurgency, urbanization and future warfare, and was awarded the 2015 Walkley Award for his reporting on the rise of Islamic State. He heads the Future Operations Research Group at UNSW Canberra, and teaches contemporary strategy, special operations, urban warfare, military innovation and adaptation. He works with advanced research agencies in the United States, Canada, and UK on technology, artificial intelligence and future conflict. 

Endnotes