In order to understand the employment of engineers in the current warfighting and peace operations contexts, it is necessary to summarise some of the history of the previous 25 years and note the changes the Engineers have undergone in order to fulfil their missions and serve as an effective wartime and peacetime force.

The last 25 years can be organised into three periods: pre-War, War, and Post-War Reconstruction. Each of these periods saw significant changes in the doctrine, structure, and role of the Australian Engineers, but not without significant debate and experimentation which allowed them (and the rest of the Australian Army) to try to define both the mission and how to achieve it.

The pre-War period was characterised by the Engineers trying to balance preparing for war, responding to natural disasters, delivering humanitarian aid, and building partner capacity while struggling to retain sufficient personnel. Throughout this period, the Engineers still focused on traditional manoeuvre warfare as part of a combined-arms structure that stretched back to the Second World War. Exercises focused on combat teaming and battlegroup tactics in conjunction with traditional infantry, artillery, armour, and supporting assets. The Army regularly practiced unimaginative operational manoeuvre across Shoalwater Bay to defeat an enemy that neither looked much like nor behaved much like a competent enemy. The focus of operations was mechanised despite the Army being primarily equipped with Vietnam-era armoured vehicles. Exercises in light operations and jungle warfare were rare above combat-team level. Arctic and mountain warfare was unknown. The Engineers consequently focused on traditional mobility and counter-mobility tasks in familiar environments – obstacle breaching (despite not having any breaching or armoured engineering vehicles), obstacle construction (which was rarely allowed to be effective enough to impact manoeuvre) and gap crossing with line-of-communication bridges (in the absence of any assault bridging equipment).

Simultaneously, the Engineers had to manage an increasing number of operational tasks outside of warfighting. The accumulating effects of climate change saw them respond to a number of tsunamis, cyclones, floods, and bushfires from 2019. Despite Government assertions that they would not rely upon the Army as the primary responder for domestic disaster situations, public outcry forced their hand to deploy forces – primarily Engineers – to affect rapid and effective relief. Additionally, Government tasked the Engineers to support increasingly frequent missions in the near region in order to counter growing Chinese influence. The Engineers provided disaster relief, helped build schools, developed military bases and local military capability, defused and disposed of explosive remnants of war, and conducted partnered missions with numerous allies in many Pacific countries. 

During this entire period, the Engineers debated their role and structure in the next conflict. As the 2020s progressed, they split into three groups of thought: the Traditionalists, the Modernists, and the Specialists. The Traditionalists favoured a continued focus on traditional manoeuvre warfare and combined arms. They argued that those structures were still going to be the decisive elements in future war so long as they were adequately augmented by emerging technologies such as drones, robotics, AI, electronic warfare, and modernised armoured equipment.

The Modernists took a much more pessimistic view. They believed the next conflict would look more like the Russo-Ukrainian War with its trenches, long-range fires, and limited manoeuvre. They saw the continued expenditure of resources on armoured vehicles and manoeuvre warfare equipment as antiquated and instead argued that the Engineers needed to focus on trench warfare, defensive tactics, and the employment of drones, anti-tank guided missiles and portable air-defence systems.

The Specialists argued that the dominating problems of the next war would not necessarily be the ones seen in Ukraine. They argued that threats such as chemical, biological, radiological, and nuclear (CBRN), sophisticated mine warfare, and amphibious manoeuvre would be significant contributors to mission success or failure in the next conflict. They argued for the development of littoral and riverine manoeuvre assets while conducting more exercises in the amphibious and CBRN spaces and increasing mining and de-mining expertise.

All three groups expected the outbreak of the Third World War to vindicate their positions. In fact, once the conflict began at the end of the decade, it was not readily apparent what the ground war would be like, if even there would be one. The initial battles of the war occurred at sea, in the air, and in space. Ground conflict was limited to Taiwan. Despite the rapid deployment of significant ground forces across Southeast Asia, South Asia, Eastern Europe, and Africa, the Third World War settled into another Phoney War as the superpowers jostled for advantage short of battle.

When it came, the beginning of the ground war was violent and shocking. It also demonstrated two major changes in warfare in the first 15 minutes of battle. The first was the vulnerability of traditional offensive support. Accurate rocket-delivered counter-battery submunitions destroyed any artillery larger than 81mm mortars within or near the battle area. Close air support became impossible due to the density of portable air defence in the front lines. By the end of the first day, any remaining rocket artillery and strike aircraft were strategic assets - their employment a three-star decision.

The second fact was the vulnerability of armoured systems. Much like carrier aviation had rendered the battleship obsolete in the Second World War, armoured vehicles were now easily destroyed or disabled by mines and small, man- and drone-portable, cheaply produced yet lethal anti-tank munitions. The larger the armoured vehicle, the easier it was to destroy. By the end of the first week of ground combat, most armoured systems remained in rear areas, poised to exploit any hoped-for breakouts much as the cavalry had hoped for in 1914-1917.

The Engineers now found themselves waging war in a new combined-arms team, one built around infantry, engineers, signallers, and medics. Most missions focused on tactical obstacles and minefield reconnaissance, and the destruction of enemy patrols, vehicles, and other high-value targets by small dismounted infantry/engineer teams. Raiding, previously the exclusive domain of Special Forces, focused on small combined-arms teams using short-range portable systems to strike signals and sensing infrastructure, command posts, and drone targets beyond the enemy’s forward positions or trenches. Some tasks, such as the maintenance of hard-wire communications between headquarters, precipitated by the vulnerability and targeting of transmissions by the enemy, looked eerily similar to the First World War. Whether in the jungles of Southeast Asia, the mountains of the subcontinent, or the ice of the Arctic and Antarctic, Engineers became dismounted warfare specialists rapidly adapting to the demands of the environment and mission. In fact, the most vital skills required in the conflict ended up being those of basic soldiering: shooting, moving, operating in disciplined small teams, controlling noise and signature emissions on the battlefield, surviving in harsh environments, and learning and adapting more rapidly than the enemy.

As the war of attrition continued, nations began to employ desperation tactics and banned weapons in an attempt to break the stalemate and force a decisive outcome. Chemical and small tactical nuclear weapons had devastating effects on the battlefield. They also served to wrest CBRN defence as an Engineers-based speciality and turn it into a truly all-corps skill, augmented by the newly created Chemical Corps to provide specialist support and reconnaissance.

The nations of the world greeted the Armistice the same way they had in 1918: some celebration, but mostly relief and sadness. Immediately, forces and funding evaporated in the rush of demobilisation… except for the Engineers. The post-war governments, focused on reconstruction and regeneration after years of devastation, again turned to the Engineers to lead those efforts. Almost overnight, the field squadrons and regiments of the Engineers transformed from dismounted mine-warfare, raiding, and trench-based combat engineers to squadrons and regiments of de-mining and construction engineers. Construction engineering, forgotten as a capability during the War, underwent a rapid rejuvenation. In fact, the Engineers had to draw from their history as they resurrected the pre-war Engineer Task Group and formed new combined-arms teams, this time focused on engineers, logisticians, medics, civil affairs, and linguists. Post-war de-mining and explosive ordnance disposal was a double-edged sword – the Engineers led the remediation of many battlefields, but they were also the only ones still suffering regular casualties.

The last 10 years have seen the Engineers leading the struggle for peace. The majority of the Corps is built around vertical construction, road building and project-management capabilities in the construction regiments, and de-mining and explosive ordnance disposal capabilities in the former combat engineer regiments. As small-intensity conflicts begin to reoccur across the globe, the Engineers are again reaching into their history for counter-insurgency tactics and techniques more akin to the wars in Afghanistan and Iraq almost half a century in the past. In the present, as the Engineers begin to debate their future focuses and structures, one thing is certain: whatever and wherever the conflict, the Engineers will draw upon their proven skill to rapidly and effectively assess, adapt, and overcome the challenges of future conflicts.