Can Australia be defeated without a single soldier setting foot on its shores? Dr. Mark Bailey argues it can — by cutting sea supply. Australia cannot be invaded easily, but it can be strangled. That is the central argument Dr. Mark Bailey, naval historian and academic in maritime trade operations at the Australian Defence Force Academy (ADFA), discusses. Sea supply — the essential subset of maritime trade without which an island state cannot prosecute a war — is Australia's defining strategic vulnerability. He traces how Australia's bipartisan 20-year industrialisation programme from 1919 to 1939 meant that by 1942, a militia mobilised from 80,000 to 700,000 and the AIF would have crushed any landing. The panel — Brigadier Corey Shillabeer commanding the Fires Brigade, Don Roach, and Joel from NIOA — drives the analysis into the present: HIMARS in 14 Regiment firing from Puckapunyal into Tasmania, three Littoral Manoeuvre Group battalions basing in Brisbane, North Queensland and Darwin, and the 2024 National Defence Strategy (NDS) framing deterrence through denial and defence at range. Essential PME on sea power, maritime trade, industrial mobilisation, and the continuity linking 1942 to Australia's fires and littoral capabilities today. Key PME Topics Covered: Sea Supply and Maritime Trade: Cutting sea supply — not invasion — defeats Australia. Bipartisan Industrial Mobilisation 1919–1939: The 20-year industrialisation programme and lessons for today's self-reliance agenda. Singapore Strategy Reinterpreted: Bailey's case that it was a trade protection and oil bunkering plan, not a fixed-base concept. HIMARS and Long-Range Coast Defence: How 14 Regiment's exercise from Puckapunyal to Tasmania is the doctrinal heir of Fort Nepean's six-inch gun. "It sounds strange to say it, but the army in this country in an island state is as sea power oriented a force as the Navy is." 0:00 Introduction — Darwin 1942 and Gunner Hudson's Lewis Gun 2:23 Dr. Mark Bailey: Sea Supply and Maritime Trade Protection 5:00 Sea Supply Defined — Admiral Noonan's Term 6:13 Alliance Framework and Australia's Maritime Trade Dependence 8:50 Singapore Strategy — Trade Protection and Oil Bunkering 11:13 Economic War Against Japan — Blockade and Pressure Mines 12:06 CSS Shenandoah in Melbourne 1865 and HMVS Victoria 16:26 World War I as Industrial War — The Lesson That Drove Industrialisation 17:24 Bipartisan Industrial Plan 1919–1939 — Armed and Ready 20:08 Anglo-Japanese Alliance Cancelled 1923 21:06 Three Wars — Distant, Defensive and Offensive 26:38 Manchurian Incident 1931 — Defence Spending Increases 28:21 LSTs, Long-Range Fires and a Corbettian Response 30:29 Panel — Lessons for Today's Decision Makers 34:25 Integrated C2 and Coastal Artillery Evolution 35:51 Surge Capacity and Stockpiles 38:04 Recapitalisation, Tyranny of Distance and Interceptor Resupply 41:08 14 Regiment HIMARS Exercise Puckapunyal to Tasmania 50:12 Precision Strike Missile and Multi-Domain Strike Doctrine 53:08 NDS Self-Reliance, National Support Base and Shadow Factories 55:17 Strategic Mobilisation Planning 59:27 Munitions and Safe and Suitable for Service 1:01:19 Loitering Munitions, Fuzing Safety and FPV Drones 1:04:05 Constant Adaptation and 20-40-40 1:08:03 Littoral Manoeuvre and Expeditionary Advanced Base Operations 1:15:57 Littoral Manoeuvre Group — Three Landing Craft Battalions 1:19:20 CAMEL — Common Autonomous Missile Effector Launcher 1:22:42 Laws of Armed Conflict, Trusted AI and Aegis Fleet Defence 1:24:36 Closing — Layered Approach, Defence at Range and Force Projection Weapons: HIMARS, Precision Strike Missile (PrSM), Common Autonomous Missile Effector Launcher (CAMEL), loitering munitions, FPV drones, Lewis gun, LSTs, Australian LHD, Aegis system. Operations: Pacific War, World War II, World War I, Manchurian Incident. Concepts: Sea supply, protection of maritime trade, Singapore strategy, mobilisation of industrial base, bipartisan industrial plan, long-range fires, littoral manoeuvre, deterrence through denial, integrated C2, multi-domain strike, autonomous systems, insensitive munitions, self-reliance, National Defence Strategy (NDS), Defence Strategic Review (DSR), sea lanes of communication, shadow factories, laws of armed conflict, layered approach, defence at range, force projection. --- Support the podcast on Patreon: / principlesofwar More episodes and articles: https://theprinciplesofwar.com/ Follow on X: https://x.com/surprisepodcast Subscribe to the channel for more Professional Military Education content. #MilitaryHistory #WW2 #PME #AustralianArmy #SeaPower #HIMARS #LittoralManoeuvre #AustralianDefence #MaritimeTrade #LongRangeFires #IndoPacific #Mobilisation #MultiDomainWarfare This Firepower Seminar lecture was produced by the Royal Australian Artillery Historical Company.