With the Strait of Hormuz effectively closed in the second week of the Iran war and roughly 20% of global crude supply interrupted, the International Energy Agency coordinated the biggest strategic release on record: 32 countries will put 412 million barrels onto world markets over four months, starting in late March 2026.
Strategic petroleum reserves are not new. They trace back to the early 20th century when the U.S. Navy switched from coal to oil and lawmakers set aside petroleum resources for wartime use. The modern system took shape after the 1973–74 oil crisis, when an OPEC export cutoff sent prices soaring and exposed supply vulnerabilities. The IEA was created to coordinate collective responses and to encourage member states to hold enough stocks to replace at least 90 days of imports; some nations, such as Japan, maintain even longer coverage.
Today IEA members hold about 1.2 billion barrels of government stocks, and industry is estimated to hold another 600 million. The U.S. contribution — an expected 172 million barrels — is nearly half of the planned release. The U.S. Strategic Petroleum Reserve, stored in salt dome caverns along the Gulf Coast, once had statutory capacity near 1 billion barrels and a working maximum around 713.5 million. In mid‑March 2026 it stood at about 415 million barrels, roughly 60% of that working maximum. After the 172 million‑barrel withdrawal the reserve will be about 243 million barrels, roughly 34% of the working maximum — the lowest level since the early 1980s. The administration plans to add roughly 200 million barrels later in 2026, restoring stocks to near their pre‑release level but not to historical capacity.
Strategic reserves do two main jobs: they replace part of a disrupted physical supply and they blunt a rapid price spike. Releases are temporary, adding a fixed stream of barrels for a few months. The current IEA release would supply on the order of 3 to 4 million barrels per day — meaningful, but well short of the roughly 10 million barrels per day currently constrained by the Hormuz closure and related disruptions.
Still, temporary releases can matter because oil prices are heavily shaped by futures markets. When traders expect extra barrels to be available in the near term, near‑term futures prices soften, which can prevent an immediate, extreme spike and reduce the likelihood that high prices persist. That’s how strategic releases moderate price surges even when they don’t fully replace lost daily production.
The U.S. has used its SPR several times; in 2022 the Biden administration released 180 million barrels after Russia’s invasion of Ukraine. A U.S. Treasury analysis found that release reduced market volatility and trimmed pump prices by an estimated 30 to 40 cents per gallon. Critics, however, argue releases can be politically motivated rather than strictly economic.
A coordinated release buys time and calms markets, but it also lowers the buffer countries have for subsequent shocks. If disruptions continue or escalate, governments may face hard choices about further releases versus preserving reserves. Some states pursue a different approach: long‑term commercial stockpiling, as China has done, to insulate itself against prolonged import interruptions.
The Iran war has reminded policymakers that strategic stocks remain relevant. They are not a substitute for sustained production, but they can temper panic, steady futures markets, and ease price pressure in the short run. The tradeoff is clear: immediate relief comes at the cost of reduced protection against future shocks.
By Scott L. Montgomery, University of Washington. Republished under Creative Commons.
