The global oil market is facing an unprecedented supply shock as disruptions through the Strait of Hormuz push countries to draw heavily on emergency reserves. While strategic stockpiles and alternative supplies have helped cushion the impact, the rapid depletion of these buffers is raising concerns about inflation, fuel prices and the challenge of rebuilding reserves.
The global energy market is navigating one of its most significant disruptions in decades after the near closure of the Strait of Hormuz sharply reduced the flow of oil and refined products. The International Energy Agency (IEA) describes the disruption as the largest supply disruption in the history of the global oil market.
The Strait normally carries around 20 million barrels of crude oil and petroleum products each day, equivalent to roughly one-fifth of global oil consumption. The disruption has therefore created consequences far beyond the Middle East, affecting fuel markets, transportation costs, inflation and economic activity worldwide.
Countries turn to emergency oil reserves
One of the main reasons the global economy has been able to absorb the supply shock is the availability of oil inventories.
In March 2026, IEA member countries agreed to make 400 million barrels of oil from emergency reserves available to the market—the largest collective emergency stock release in the agency’s history.
The reserves are effectively acting as a buffer between a sudden loss of supply and consumers who still need fuel. Governments can release strategic stocks, while private companies can also draw down inventories when regulations allow them to do so.
The IEA says more than 300 million barrels of emergency stocks had been released by its member countries by September, while global observed inventories had fallen by more than 500 million barrels from the beginning of the conflict.
The United States’ strategic reserve comes under pressure
The United States has also been using its Strategic Petroleum Reserve to help supply the market.
The purpose of the reserve is to provide an emergency buffer during major disruptions such as wars, natural disasters or severe supply interruptions. The current crisis has put that buffer under significant pressure.
The issue is not simply whether the United States or other countries still have oil in storage. The bigger question is how much emergency capacity remains if another major disruption occurs before inventories can be rebuilt.
Why the Strait of Hormuz matters
The importance of the Strait of Hormuz comes from the enormous volume of energy that passes through the narrow waterway.
According to the IEA, around 20 million barrels per day moved through the Strait in 2025, representing about 25% of global seaborne oil trade. Alternative export routes exist, but their capacity is limited compared with the volume normally transported through the Strait.
The disruption has also affected refined products. Diesel, jet fuel and LPG markets have faced particular pressure, increasing costs for transportation, aviation, industry and other sectors.
Oil inventories have become the shock absorber
The global oil market entered the crisis with substantial inventories. The IEA estimates that global oil storage reached around 8.2 billion barrels before the conflict, providing an important cushion when supplies were disrupted.
That cushion, however, has been shrinking.
The IEA reported that global observed oil inventories fell by 69 million barrels in July, with cumulative stock draws since the end of February reaching around 410 million barrels by the end of July.
The IMF has similarly noted that inventory drawdowns, increased production outside the Gulf and changes in oil demand helped prevent an even larger price shock.
The economic impact goes beyond petrol prices
An oil supply shock can quickly spread throughout the economy.
Higher crude prices increase costs for refineries and fuel distributors. More expensive diesel raises transportation and logistics costs, while higher jet fuel prices increase costs for airlines. Manufacturers, farmers, construction companies and other energy-intensive businesses can also face higher operating expenses.
Those costs can eventually reach consumers through higher prices for food, transportation, manufactured goods and services.
This creates a difficult challenge for central banks. Monetary policy can influence demand and inflation expectations, but higher interest rates cannot create additional oil supply or reopen an international shipping route.
The IMF has warned that the energy shock could put renewed pressure on inflation, although it has also noted that the global economy has so far absorbed the shock better than initially feared.
Rebuilding the reserves could become the next challenge
Perhaps the biggest long-term issue is what happens after the immediate crisis.
Emergency reserves exist to be used during major disruptions. But once the situation stabilises, governments and companies will need to replenish the oil that has been withdrawn.
That process could create additional demand for crude. Instead of releasing oil into the market, governments and companies would become buyers, potentially adding upward pressure to prices if replenishment happens rapidly.
The timing will therefore be crucial. Rebuilding too quickly could increase demand at a time when markets remain tight. Waiting too long, meanwhile, could leave countries with smaller emergency buffers if another supply disruption occurs.
The IMF has stressed the importance of rebuilding inventories and diversifying energy supply and transportation routes to strengthen resilience against future shocks.
A changing global energy landscape
The crisis has also highlighted the risks of relying heavily on a small number of critical energy routes.
The IEA says the disruption has demonstrated the importance of diversifying both energy sources and transportation routes. Governments are also responding through fuel conservation measures, alternative energy supplies and efforts to reduce dependence on oil.
For now, the global oil market continues to adjust through a combination of emergency inventories, alternative supply routes, production changes and lower demand.
But the experience has exposed an important vulnerability: emergency reserves can soften an energy shock, but they cannot provide unlimited protection.
As the world works to restore disrupted oil flows and rebuild depleted inventories, the next phase of the crisis could therefore focus less on releasing emergency barrels—and more on replacing them.
The central question for the global economy is no longer simply how much oil can be released during the current disruption, but how quickly the world’s energy safety net can be rebuilt before the next shock arrives.