Strait of Hormuz Closure Triggers Largest Oil Supply Disruption in History
The International Energy Agency (IEA) has warned that the closure of the Strait of Hormuz has caused the largest disruption to global oil markets on record. The agency estimates that oil supply could fall by roughly 8 million barrels per day (bpd) in March, representing about 8% of global production.
To stabilize markets and offset the loss of Middle Eastern supply, IEA member countries agreed to release a record 400 million barrels from strategic oil reserves. The coordinated move aims to prevent a sharp surge in oil prices and ensure sufficient supply to global markets.
Below are some of the most significant oil supply disruptions in modern history.
The 1973–1974 Arab Oil Embargo
One of the most dramatic oil shocks occurred during the 1973–1974 Arab oil embargo, triggered by the Yom Kippur War. The conflict began on October 6, 1973, when Egypt and Syria launched coordinated attacks against Israel.
In response, Arab oil producers—acting through the Organization of Arab Petroleum Exporting Countries (OAPEC)—announced an immediate 5% reduction in oil production, followed by additional monthly cuts. The move aimed to pressure Western nations to force Israel to withdraw from territories captured during the 1967 Six-Day War.
U.S. National Security Council estimates at the time suggested the embargo would leave the United States short by 2–3 million barrels per day, while the total shortage among affected countries could reach 4.5 million bpd.
The embargo was formally announced on October 17, 1973, and remained in effect against the United States until March 1974.
Oil prices surged dramatically during the crisis, rising from $2.90 per barrel to $11.65 by January 1974. In response, the U.S. government introduced fuel conservation measures, encouraged domestic energy production, and developed emergency energy legislation. The crisis also led to the creation of the International Energy Agency in 1974, designed to coordinate global responses to oil supply disruptions.
The 1978–1979 Iranian Revolution
Another major oil supply shock occurred during the Iranian Revolution of 1978–1979. Political upheaval led to the fall of Shah Mohammad Reza Pahlavi and the rise of Ayatollah Khomeini.
As unrest spread, Iranian oil production dropped sharply by 4.8 million barrels per day, representing around 7% of global oil supply by early 1979.
Oil prices began climbing rapidly in mid-1979 and more than doubled between April 1979 and April 1980. The increase was driven by fears of further disruptions, speculative stockpiling, and strong global demand.
The crisis contributed to rising inflation in the United States. In August 1979, Paul Volcker was appointed chairman of the Federal Reserve and implemented aggressive monetary tightening to combat inflation. Although the policies eventually curbed stagflation, they also pushed the U.S. economy into a severe recession.
The 1990–1991 Gulf War Oil Shock
The 1990 invasion of Kuwait by Iraq created another significant disruption to global oil supplies. The subsequent United Nations embargo on Iraqi and Kuwaiti oil removed approximately 4.3 million barrels per day from global markets.
Before the war, Iraq produced around 3.1 million bpd, exporting roughly 2.7 million bpd, while Kuwait produced 1.8 million bpd and exported 1.7 million bpd. Together, the two countries accounted for nearly one-third of the Persian Gulf’s oil production and exports.
Oil prices surged during the crisis. Brent crude climbed from about $17 per barrel in July 1990 to roughly $36 by October 1990, before falling again after the war ended in February 1991.
In response, the IEA activated its Coordinated Energy Emergency Response Plan, preparing to release 2.5 million barrels per day to the market through stockpiles, demand reductions, and fuel switching.
Hurricanes Katrina and Rita in 2005
Natural disasters can also disrupt oil supply. In August 2005, Hurricane Katrina struck the U.S. Gulf Coast, shutting down large volumes of offshore oil production.
At the peak of the disruption on August 29, approximately 1.38 million barrels per day of production were halted. Output losses gradually declined but remained around 840,000 bpd by mid-September.
Just weeks later, Hurricane Rita caused further damage, with the combined disruptions temporarily shutting in up to 1.53 million barrels per day.
The U.S. government responded by releasing 9.1 million barrels of crude oil from the Strategic Petroleum Reserve to refineries. The United States also joined an IEA-coordinated release of 30 million barrels from global emergency stockpiles.
Authorities introduced additional emergency measures, including allowing the use of winter-blend gasoline, relaxing diesel sulfur limits, and temporarily waiving shipping restrictions to ease fuel transport between U.S. ports.
The 2022 Russian Invasion of Ukraine
Russia’s full-scale invasion of Ukraine in 2022 triggered a global energy crisis as Western nations sought to reduce their dependence on Russian oil and gas.
Oil prices surged more than 50% within weeks, reaching some of the highest levels seen since 2008 as markets scrambled to secure alternative supplies.
To counter the spike, then-U.S. President Joe Biden ordered the release of 180 million barrels of crude oil from the Strategic Petroleum Reserve over six months.
Western governments also introduced price caps on Russian oil exports, aiming to limit Moscow’s war revenue while keeping Russian oil flowing into global markets to avoid further supply shocks.
These historic events highlight how geopolitical conflicts, political upheaval, and natural disasters can dramatically reshape global energy markets.
