The 2023 Defence Strategic Review warned that Australia is experiencing its most challenging circumstances in decades with contests taking place across diplomatic, economic, military, and strategic levels. Traditional kinetic warfare is increasingly being replaced by or complemented with hybrid tactics, with climate change and advancing technologies such as AI and quantum adding further complexity to Australia’s security climate.

Within this strategic environment Army has been tasked by the 2024 National Defence Strategy (NDS) with defending our northern approaches, a region made up of littoral environments becoming rapidly more urbanised and populated. Increasingly, Army will require versatility in transitioning across littoral-jungle-urban domains while undertaking tasking from seizing and holding terrain to peacekeeping and humanitarian assistance – within likely short periods of time.

I argue that Army can best adapt to this changing character of modern war by continuing along a path perhaps less noteworthy than the acquisition of new technology or hard power capability alone: it lies in proactive strategies in infrastructure, training, and cooperation in our northern approaches.

The Urban Littoral

An estimated 75 per cent of the world’s population and 80 per cent of capital cities are located along coastlines, a trend expected to continue. The future of littoral operations will need not only to streamline manoeuvre from sea to land, but also be effective in transitioning into populated city environments that await onshore.

Urban conflict has been described as the most difficult form of warfare, favouring occupying forces. The urban defender maintains the advantage in tactical positioning, freedom of manoeuvre, and fortification, while the attacker is limited in intelligence, reconnaissance, cover, and concealment. Including amphibious manoeuvre within this calculus has led to the blending of urban and littoral operations being labelled as the ‘worst of both worlds.’

This increasing complexity represents challenges for Army but also opportunity. Army can best meet its NDS tasking in projecting and sustaining land and strike capability in the urban littoral domain through proactive cooperation, training, and infrastructure with allies. This will allow Army to seize the initiative at short notice in taking defensive positions in the urban littoral to deny and repel enemies, and support logistical sustainment, follow-on deployment of forces, and retention of sea and air control. Cooperation and presence with a partner such as Papua New Guinea (PNG) is a prime example.

Papua New Guinea and the Littoral

PNG has been described as Australia’s ‘security shield’ and has a long history with Australian security and littoral operations. The 1942 PNG Kokoda campaign was crucial in halting the advance of Japan through the Pacific, and the Battle of Milne Bay saw the Allies deliver the first defeat of Japanese forces on land. The New Guinea offensives of 1943-44 were the single largest series of interconnected military operations in Australian history, and Operation POSTERN at Lae represented Australia’s first major amphibious landing since Gallipoli. When Australian defence strategy refers to littoral manoeuvre in our northern approaches, it looks to this region.

Infrastructure for Urban Littoral Capability

There are opportunities for Australian presence in PNG to support urban littoral capability. Infrastructure could emulate existing engagements at the Royal Malaysian Air Force base at Butterworth. This base hosts an Australian Army company, air force squadron, plus a joint health command; and allows for regional aerial surveillance, intelligence gathering, and the rotation and jungle training of Army personnel. A PNG version of this arrangement could specialise in urban littoral warfare training and sustainment for Australian and PNG soldiers, allowing for development of joint capability and interoperability in the littoral battlespace.

Joint infrastructure could further bolster Army ability to rapidly deploy littoral resources across the region. This would be essential in responding to potential adversaries in our northern approaches and in establishing defence of urban littoral centres, as well as securing other key infrastructure such as ports and airfields. This versatility would assist Army in maintaining asymmetric advantage and allow for air and sea control to support ongoing littoral operations and defence as needed.

This requirement is evident from 1943 amphibious operations at Lae during Operation POSTERN. Air and sea control allowed the Allies and 9th Division relative security during amphibious landings and supported deployment of airborne troops from 7th Division further north of the main effort. Allied forces employed a pincer movement on Japanese positions, with air and sea control further ensuring enemy forces were unable to be resupplied.

The repurposing of Igam Barracks at Lae for urban littoral deployment can further support capability, as well as the employment of Lombrum Naval Base to house Army and Navy assets. Utilising existing infrastructure would further facilitate the rapid deployment of long-range anti-access/area-denial capability into the region to respond to or deny any adversary from emplacing their own forces or long-range assets. These bases can then act to support electronic warfare, communication and command functions, and logistics during conflict, as well as bolster PNG cyber resilience, maritime patrolling, and humanitarian responses in peacetime.

Rather than deploying as required from northern Australia, PNG-Australian infrastructure can work to ensure lines of communication for urban littoral operations are maintained during a potential conflict. This further protects Australia’s maritime trade – the majority of which traverses the northern approaches – and digital connectivity via subsea cables. Logistics, resupply, and the deployment of follow-on forces were challenges during Australian littoral operations in WWII, and have been identified as an ongoing challenge by the US Marine Corps in Force Design 2030 planning. Regional infrastructure will assist in meeting this challenge.

Urban Littoral Training and Exercise

Army presence in PNG can further facilitate joint training in the urban littoral. PNG 2nd Battalion and Australian Army 3 RAR have already conducted high-level training together on PNG-based Exercise Wantok Warrior, which included moving from air and amphibious assets into jungle and urban clearances. These forms of activities can be further accelerated by including other relevant Army corps and Navy forces, thereby disseminating urban littoral capability. These opportunities can be expanded into multilateral littoral training and exercises with other near north partners such as Indonesia and Timor-Leste and take place in Australia at Shoalwater Bay, PNG, or archipelagic environments close to other neighbours.

Partners such as the US, Japan, and South Korea can further be drawn in. Army never fights alone and amphibious operations during WWII each worked in conjunction with allied forces. Any future potential conflict in the urban littoral will likely not only leverage that capability again, but also utilise local partner militaries. Establishing these links and interoperability early will assist in developing a skilled Army amphibious capability ready for rapid tasking, with close multilateral integration with regional partners such as PNG and Indonesia, as well as the US, Japan, and others.

Capability in littoral and urban environments can be included as a part of the initial employment training continuum for relevant corps such as infantry and engineers. Army Reservists in Western Australia already undertake amphibious training and this capability could be extended to other unit locations. Just as full- and part-time Army personnel contribute to Operation Resolute and Exercise Talisman Sabre, they could further undertake rotations through the Army Amphibious Task Force. This opportunity might be extended to PNG and partner personnel, considering integration efforts already take place through Exercise Kumul Exchange and a PNG officer holds a senior position in the 3rd Brigade.

Urban Littoral Landings

Army infrastructure, presence, and joint interoperability with littoral partners can work to bolster Army capability in responding to adversaries in the urban littoral. The development and inclusion of training in this domain and disseminating those skills across Army will complement this capability. Littoral operations are complicated activities requiring air and sea control, the shaping of landing environments through reconnaissance, intelligence, and security, as well as the moving of high signature landing crafts to areas of operations. Amphibious landings must be supported by follow-on forces; the establishment of command, communication, and logistical capacity; and reconstitution for subsequent operations. As at Operation POSTERN, successful amphibious operations will likely necessitate further landings to pursue enemy forces and clear urban centres.

Preparing for the Future

The Australia-PNG model described can be applied to other partners in the region. Each arrangement could cater to the political, security, and economic climates of partner nations. Cooperation with Timor-Leste and Indonesia are examples in our northern approaches, as well as further north into Southeast Asia. Regional capability and people-to-people links in urban littoral operations will act as a powerful deterrent for any external actor wishing to coerce or dominate the region.

Army preparation for any potential conflict in the urban littoral domain will be essential to success against a near-peer adversary. Army troops deployed for Operation POSTERN had previously focused on desert warfare in North Africa and friction points transitioning into the amphibious domain arose. Army learned and so the execution of Operation OBOE in 1945, Australia’s largest ever amphibious assault, was the culmination of WWII littoral capability. In building urban littoral capability now, Army can learn from those lessons, take positional advantage, and be ready to fight alongside allies if the need arises.