Australia may be sitting on one of the most dangerous economic vulnerabilities in its modern history, and it has nothing directly to do with house prices, interest rates or government debt. It concerns something more basic: diesel fuel. Without diesel, the trucks that deliver food to supermarkets cannot operate normally, farmers cannot harvest crops, mines cannot maintain production, and much of the machinery supporting the Australian economy becomes useless. An escalating war involving Iran could therefore inflict damage upon Australia without a single missile being fired in our direction. The weapon would be disruption of international fuel supplies, and the consequences could extend into every Australian household.
Leith van Onselen, writing in Macrobusiness on 2 November 2026, argues that diesel shortages represent Australia's greatest recession risk. His warning comes as the conflict in the Middle East, combined with continuing disruption associated with Russia, places enormous pressure upon global refining capacity and petroleum supply chains. International diesel prices have reached extraordinarily high levels, while damaged refineries, interrupted crude oil shipments and export restrictions have reduced the availability of refined fuel. Van Onselen reports estimates suggesting that effective global refining capacity has been reduced by approximately 10 per cent. This is not a universally established figure, but it illustrates the scale of the disruption being discussed. When the world loses access to even a relatively small proportion of its refining capacity, the consequences can be severe because modern economies depend upon a continuous flow of petroleum products.
The problem for Australia is that diesel is not merely another consumer commodity. It is a fundamental input into economic production. Petrol is principally associated with private cars, although it also supports commercial activities. Diesel, by contrast, powers much of the machinery responsible for moving goods, extracting resources and producing food. An interruption to diesel supplies therefore threatens the productive economy itself. The Institute for Energy Economics and Financial Analysis estimated in April 2026 that Australia imports approximately 87 per cent of its diesel. It also described Australia as the world's largest diesel importer. This extraordinary dependence has developed over decades as domestic oil refining capacity has contracted and successive governments have become increasingly comfortable relying upon international markets.
Australia once operated eight major oil refineries. Today only two remain, at Geelong in Victoria and Lytton in Queensland. The closure of the other refineries reflected commercial pressures, changing international markets and the economics of refining. It would be too simplistic to attribute every closure to environmental policy. Nevertheless, successive governments failed to ensure that the resulting dependence upon imported fuel was matched by sufficiently robust domestic reserves and alternative supply arrangements. The consequences of that neglect are now becoming apparent. Australia obtains much of its refined petroleum from Asian countries, particularly Singapore, South Korea and Malaysia. At first glance this might appear to provide some protection against a Middle Eastern conflict. After all, Australia is not importing all its diesel directly from Iran or the Persian Gulf. But this apparent security is deceptive.
The Asian refineries supplying Australia depend heavily upon crude oil imported from the Middle East. Singapore and South Korea, in particular, have traditionally obtained substantial proportions of their crude oil from the region. The Strait of Hormuz is therefore a critical part of Australia's indirect fuel supply chain. A more serious interruption to shipping through the strait can reduce the crude oil available to Asian refineries. Those refineries may then reduce output, increase prices or prioritise their domestic markets. Australia can consequently experience diesel shortages even though its immediate suppliers are thousands of kilometres away from the fighting. This is the vulnerability of globalised supply chains. A product may arrive from a neighbouring region while depending upon resources transported through a distant geopolitical chokepoint. The final point of purchase tells us relatively little about the security of the entire production process.
The Strait of Hormuz has long been recognised as one of the world's most strategically important maritime passages. Large volumes of crude oil and liquefied natural gas normally pass through this narrow waterway. Military attacks, shipping restrictions, insurance difficulties and threats against tankers can interfere with energy supplies even without a complete physical blockade. If the Iranian conflict escalates further, shipping companies may become unwilling to risk vessels and crews. Insurance premiums could rise dramatically. Oil-producing countries might encounter difficulties exporting their products, while importing nations compete fiercely for whatever supplies remain available. The consequences would be felt particularly strongly in countries such as Australia, where the economy is geographically dispersed and heavily dependent upon road freight.
Consider the food supply chain. Farmers use diesel-powered tractors, harvesters, irrigation equipment and other machinery. Agricultural produce is transported by truck to processing facilities, distribution centres and supermarkets. Refrigerated transport requires reliable energy, and many regional communities depend upon long-distance deliveries. A serious diesel shortage would therefore affect food production and distribution simultaneously. Farmers might face difficulties harvesting crops, while transport companies could struggle to deliver produce to markets. The resulting scarcity would increase food prices and could lead to temporary shortages of particular products. The effects would not be confined to remote communities. Australia's major cities depend upon extensive logistics networks that move enormous quantities of food and consumer goods every day. Supermarkets do not maintain unlimited inventories, and disruptions to freight transport can rapidly affect product availability.
Mining would be another major casualty. Australia's resources sector depends upon substantial quantities of diesel for heavy vehicles, excavation equipment, remote operations and supporting transport infrastructure. Although some mining operations are becoming electrified, diesel remains essential across much of the industry. A reduction in diesel availability could therefore restrict mineral production and exports. This would be especially damaging because mining provides substantial export revenue and contributes significantly to government taxation and royalties. The economic consequences could become self-reinforcing. Reduced mining exports would weaken national income, while higher transport costs would increase prices throughout the domestic economy. Businesses would face rising operating expenses at precisely the moment when consumers were becoming less able to afford their products. This is how a fuel shortage can become a recessionary shock.
Economists distinguish between demand shocks, where spending declines, and supply shocks, where the economy's capacity to produce goods and services is impaired. A severe diesel shortage would be primarily a supply shock. It would make production and transportation more expensive and, in extreme circumstances, physically impossible. The result could be the unpleasant combination of falling economic output and rising prices, commonly described as stagflation. This would create a particularly difficult problem for the Reserve Bank of Australia. Higher fuel prices can contribute to inflation, encouraging tighter monetary policy. But higher interest rates cannot produce additional diesel or repair damaged refineries. They may instead weaken economic activity further. Conversely, lowering interest rates to support businesses and households would not resolve the underlying shortage of fuel. Monetary policy is poorly equipped to overcome a physical interruption to essential supplies.
The federal government would face similar difficulties. It could reduce fuel excise, subsidise transport operators or provide financial assistance to affected industries. Such measures might soften the economic consequences, but they would not create additional physical supplies of diesel. A government can distribute purchasing power through financial policy. It cannot manufacture petroleum products through parliamentary legislation. Australia's fuel reserves provide some protection, but their limitations are significant. According to the Australian Government's National Fuel Security Plan, as at 27 October 2026, Australia held approximately 34 days of diesel coverage under its Minimum Stockholding Obligation. Petrol coverage stood at 41 days and jet fuel at 29 days. These figures do not mean that the country would automatically run out of diesel after 34 days. They represent a particular measure of available stocks relative to normal consumption, and additional supplies continue to arrive through international trade. Nevertheless, they illustrate the relatively limited buffer available if imports were seriously interrupted.
The government reported that at least 3.1 billion litres of crude oil and refined petroleum products were scheduled to arrive over the following four weeks. It also stated that fuel stocks remained broadly consistent with long-term averages and that supplies were continuing to reach Australia. This is important context. Australia is not presently experiencing a complete national fuel supply collapse. The danger concerns what could happen if international disruption becomes more severe or prolonged. There is a difference between a vulnerable supply chain and a supply chain that has already failed. Yet the government's reassuring statements should not obscure the structural weakness. A country dependent upon imported fuel must remain concerned about the reliability of international shipping, refining capacity and the willingness of suppliers to continue exporting during a crisis.
The experience of the COVID-19 pandemic demonstrated how quickly international supply chains can become disrupted when governments and businesses respond to emergencies. Medical equipment, pharmaceuticals, industrial components and ordinary consumer goods suddenly became difficult to obtain. A severe diesel shortage would be more economically fundamental because fuel is required to move many of the other goods upon which society depends.
There is also the danger of international competition for scarce supplies. During a prolonged energy crisis, governments may prioritise their own domestic consumers. Export restrictions can appear attractive politically, even when they worsen shortages elsewhere. Australia, with its relatively small population and limited domestic refining capacity, could find itself competing against much larger economies for available diesel.
The country's mineral wealth would provide little immediate protection. Australia exports enormous quantities of coal, natural gas and other resources, but those commodities cannot simply be poured into the fuel tanks of existing diesel trucks and agricultural machinery. This is one of the great paradoxes of Australian energy policy. A nation extraordinarily rich in energy resources can nevertheless remain vulnerable to shortages of the particular fuels required by its transport and production systems. The distinction between energy abundance and energy security is fundamental. There are potential long-term alternatives. Electrification of transport, increased domestic refining capacity, alternative liquid fuels, improved rail freight and more efficient logistics, could all reduce Australia's dependence upon imported diesel. But these changes require investment, infrastructure and time. A diesel-powered agricultural machine cannot necessarily be replaced overnight with an electric equivalent. Remote mining operations cannot instantly redesign their equipment fleets. Heavy transport companies cannot abandon existing vehicles simply because international petroleum markets become unstable. Technological transitions must therefore be assessed against the practical requirements of existing industries.
There is a case for expanding domestic fuel storage and maintaining strategically important refining capabilities, even where purely commercial calculations favour cheaper imports. National security sometimes requires redundancy that appears inefficient during periods of normal international trade. The same principle applies to food production, pharmaceuticals and other essential industries. A country that relies entirely upon uninterrupted international commerce may enjoy lower costs in ordinary circumstances while exposing itself to serious vulnerabilities during emergencies. A resilient economy requires more than the ability to purchase goods at the lowest available price. It requires the capacity to continue functioning when markets and supply chains are disrupted. The Australian government's response to the 2026 fuel crisis has included measures to strengthen strategic reserves and support the acquisition of additional supplies. These are welcome acknowledgments of the problem, but they do not erase decades of growing import dependence.
The more difficult question is whether Australia should reconsider the broader economic philosophy that treats global supply chains as permanent substitutes for domestic productive capacity. For many years the assumption was that international markets would reliably supply whatever Australia required. If domestic production became relatively expensive, imports were considered an efficient alternative. In ordinary circumstances this logic often made commercial sense. But efficiency is not the same as resilience. A supply chain optimised for low cost may contain very little spare capacity. When disruption occurs, there may be few alternatives available. The economic savings accumulated over many years can then be overwhelmed by the consequences of a relatively brief crisis. The Iranian war provides a powerful demonstration of this problem. Australia is geographically distant from the Middle East, yet its farmers, truck drivers, miners and consumers can all be affected by military developments thousands of kilometres away. The global economy has connected distant regions so closely that warfare in one area can disrupt essential production in another.
The risks would become particularly severe if the conflict expanded to involve additional regional states, sustained attacks upon oil infrastructure or a prolonged interruption to shipping through the Strait of Hormuz. A major escalation could reduce available crude oil supplies, force further refinery shutdowns and intensify competition for refined petroleum products. Diesel prices might rise to levels that make some commercial activities uneconomic even before physical shortages become widespread. Transport operators working on narrow margins could reduce services or increase charges. Farmers could postpone non-essential operations. Construction projects might become more expensive or be delayed. Mining companies could reconsider production schedules. Eventually the cumulative effect could reduce employment, investment and national economic output.
Whether such a shock would produce an Australian recession would depend upon its severity, duration and the effectiveness of government and industry responses. A short disruption might primarily increase prices. A prolonged shortage could cause substantial reductions in production. Van Onselen's warning is therefore best understood as identifying a serious recession risk rather than predicting an inevitable economic collapse. Alarmism can encourage counterproductive behaviour. Panic buying and unnecessary stockpiling can create local shortages even when national supplies remain adequate. Households should maintain sensible emergency preparations, but hoarding large quantities of fuel introduces fire hazards and can deprive essential users of supplies. The priority during a serious shortage should be preserving diesel for essential activities, including emergency services, food production, freight, water infrastructure and other critical operations. Governments may need contingency plans for allocating scarce supplies if market mechanisms alone cannot protect essential services. Such arrangements should be transparent, temporary and subject to appropriate oversight.
For ordinary Australians, the lesson is that fuel security is not an abstract concern confined to economists and defence planners. It affects the availability and price of food, the operation of businesses and the capacity of communities to function. A household may never purchase diesel directly, yet almost everything it consumes has probably depended upon diesel at some stage of production or transportation. The national vulnerability is therefore much greater than the number of diesel vehicles on Australian roads might suggest.
There is also a broader lesson about the limits of globalisation. Dependence upon distant suppliers becomes dangerous when essential goods cannot be readily substituted or produced domestically. A sensible national policy should distinguish between products that can safely be imported and those whose prolonged absence would threaten the functioning of society. Diesel belongs firmly within the second category.
Australia's political leaders should therefore treat fuel security as a central economic and national security issue, not merely another matter for commercial petroleum distributors. The country needs realistic contingency planning, adequate reserves, diversified suppliers and serious consideration of domestic productive capacity. It also needs an honest public discussion about the trade-offs between economic efficiency, environmental objectives and national resilience. None of these measures can eliminate the consequences of a major international energy crisis. But they can reduce the likelihood that an external conflict will produce a domestic economic catastrophe.
https://www.macrobusiness.com.au/2026/11/diesel-shortages-are-australias-greatest-recession-risk/