The World's Most Important Waterway Has Gone Dark

For five days now, the Strait of Hormuz — the 21-mile-wide passage between Iran and Oman through which roughly 20% of the world's daily oil supply flows — has been effectively shut down.

Tanker traffic has collapsed from normal levels to near zero. Over 150 ships sit anchored outside the strait, their crews unable or unwilling to transit. At least five oil tankers have been struck by Iranian drones and missiles, with one reported on fire. Four seafarers are confirmed dead, including two Indian sailors — Captain Ashish Kumar among them — who were killed when the SKYLIGHT tanker was hit on Sunday.

And now, the insurance industry has pulled the plug. Major underwriters have cancelled war-risk coverage for vessels transiting the strait, making it financially impossible for most commercial operators to attempt passage even if they wanted to.

The Strait of Hormuz crisis is no longer a sideshow to the Iran war. It is becoming the war's most consequential front.

How We Got Here

When the U.S. and Israel launched Operation Epic Fury on February 28 — coordinated strikes targeting Iran's military facilities, nuclear sites, and leadership — Iran's response was not limited to missiles aimed at Israel or drones targeting U.S. bases in the Gulf.

The Islamic Revolutionary Guard Corps (IRGC) issued direct warnings prohibiting vessel passage through the Strait of Hormuz. Then it backed those warnings with force.

The attacks on shipping began almost immediately. Tankers were hit with drones and anti-ship missiles. The IRGC deployed fast boats and naval mines in the shipping lanes. Within 48 hours, tanker traffic had dropped by 70%. Within four days, it was effectively zero.

On Wednesday, the crisis deepened further when a U.S. submarine sank an Iranian warship off Sri Lanka — an engagement far from the Gulf that signaled the naval conflict is no longer confined to the Middle East.

The Energy Math

The numbers are staggering. The Strait of Hormuz normally handles:

  • 20 million barrels of oil per day — roughly 20% of global seaborne oil trade
  • Major LNG shipments from Qatar, which supplies 12-14% of Europe's natural gas
  • Crude exports from Saudi Arabia, UAE, Iraq, Kuwait, and Qatar

In 2024, an estimated 84% of crude oil and condensate moving through the strait was destined for Asian markets — China, Japan, South Korea, and India. These economies are now scrambling for alternative supply.

Brent crude has surged as much as 13% to $82 per barrel, and analysts warn prices could push toward $100 if the disruption persists for weeks. War-risk insurance premiums, which had already tripled before the conflict began, are now effectively infinite — insurers simply won't write the policies.

For context: before the crisis, war-risk premiums for the strait had risen from 0.125% to 0.2-0.4% of ship insurance value per transit. For a very large crude carrier, that represented an increase of roughly $250,000 per voyage. Now, there is no price at which coverage is available.

Who Gets Hurt

The impact is not evenly distributed.

South Korea and Japan are the most exposed developed economies. South Korea imports 98% of its fossil fuels, with roughly 70% of its oil and 30% of its LNG coming through the strait. The KOSPI's historic 18% two-day crash was directly tied to this vulnerability.

India is facing both supply disruption and human cost. Indian crew members are among the casualties, and India imports roughly 60% of its crude from Middle Eastern suppliers who ship through Hormuz.

China has been quieter publicly but is deeply affected. As the world's largest oil importer, China receives a significant share of its crude through the strait. Beijing's strategic petroleum reserves provide a buffer, but not an indefinite one.

Europe faces a different problem: LNG. Qatar's gas exports to Europe transit the strait, and with Russian pipeline gas already curtailed since 2022, the loss of Qatari LNG would leave Europe facing a potential energy crisis heading into the 2026 shoulder season.

The United States, despite being a net energy exporter, is not immune. Global oil prices are global — even domestically produced oil is priced at the world market rate. American consumers will feel this at the gas pump.

The Insurance Crisis Within the Crisis

The collapse of war-risk insurance is a force multiplier. Even if Iran were to suddenly announce a ceasefire in the strait, shipping would not resume immediately. Insurers would need to reassess risk, rewrite policies, and set new premiums — a process that takes days to weeks.

This means the economic damage from the Hormuz closure will outlast the military operations that caused it. Supply chains that were disrupted for five days will take weeks to fully restore. Contracts that were cancelled will need to be renegotiated. Spot market prices for oil and LNG will remain elevated long after the first tanker transits the strait again.

Strategic Implications

Iran has long warned that the Strait of Hormuz was its ultimate leverage — the weapon it would use if its survival were threatened. The international security establishment debated for decades whether Iran would actually follow through.

Now we know.

The closure has demonstrated that a single determined state actor can effectively shut down 20% of the world's oil supply — and that the global economy has no quick alternative. Pipeline capacity from the Gulf to the Red Sea and Mediterranean exists but is limited. Strategic reserves in the U.S., China, Japan, and Europe provide months of buffer, not years.

The longer the strait stays closed, the more the global economy rewires around its absence. And some of that rewiring may prove permanent.