What Is the Strait of Hormuz?

What Is the Strait of Hormuz?

The Strait of Hormuz is a narrow waterway that connects the Persian Gulf to the Gulf of Oman and the broader Arabian Sea. It lies between Iran to the north and Oman (and the UAE) to the south. At its narrowest point, the strait is just 21 miles (34 km) wide, with navigable shipping lanes in each direction only two miles across, separated by a two-mile buffer zone.

Despite its modest size, the Strait of Hormuz is the most strategically important maritime chokepoint on Earth. The overwhelming majority of oil and liquefied natural gas (LNG) exported from the Persian Gulf region must pass through this single bottleneck to reach global markets.

Why It Matters for Global Energy

The numbers tell the story:

• 17–21 million barrels of oil per day transit through the Strait of Hormuz — approximately 20% of global oil supply
• Saudi Arabia, Iraq, the UAE, Kuwait, and Qatar depend on the strait to export the vast majority of their hydrocarbons
• Qatar, the world's largest LNG exporter, ships virtually all of its liquefied natural gas through the strait
• The strait carries approximately one-third of all seaborne-traded crude oil worldwide

There are no viable alternative routes for most Gulf producers. While Saudi Arabia and the UAE have limited pipeline capacity that bypasses the strait (such as the East-West Pipeline to the Red Sea and the Habshan-Fujairah pipeline), these can handle only a fraction of total Gulf exports. For Qatar, Iraq, and Kuwait, there is no meaningful bypass infrastructure at all.

A disruption at Hormuz therefore translates directly into a disruption of global energy markets. Even brief closures or threats send oil prices surging, as traders price in the possibility of sustained supply interruption.

Who Controls the Strait?

The Strait of Hormuz is an international waterway governed by the United Nations Convention on the Law of the Sea (UNCLOS), which guarantees the right of transit passage for all vessels — including warships — through straits used for international navigation. Iran and Oman are the two coastal states.

Iran controls the entire northern shoreline of the strait, including several islands — Abu Musa, Greater Tunb, and Lesser Tunb — that sit directly in or near the shipping lanes. These islands, contested by the UAE, give Iran a forward military position in the middle of the waterway.

Oman controls the southern shoreline, including the Musandam Peninsula, which juts into the strait. Oman has historically maintained a neutral posture and has served as a diplomatic intermediary between Iran and Western powers.

In practice, Iran's geographic position gives it the strongest hand. Its coastline, islands, and coastal mountains provide natural positions for military assets that can threaten any vessel transiting the strait.

Iran's Military Position

Iran has spent decades preparing its military to control the Strait of Hormuz in a crisis. The Islamic Revolutionary Guard Corps Navy (IRGC-N) — distinct from the regular Iranian Navy — is specifically organized and equipped for operations in the strait's confined waters:

• Anti-ship missiles: Chinese-origin C-802 and indigenous Noor cruise missiles, along with Khalij Fars anti-ship ballistic missiles, are deployed along the Iranian coastline. Their combined range covers every part of the strait.
• Fast attack boats: The IRGC Navy's signature capability — dozens of small, fast, heavily armed boats designed for swarm tactics in confined waters. These vessels can overwhelm larger warships through speed and numbers.
• Naval mines: Iran possesses thousands of sea mines of various types — contact mines, influence mines, and advanced mines that can be programmed to target specific vessel types. Even a small number of mines in shipping lanes creates massive disruption.
• Submarines: Iran's fleet of Kilo-class diesel-electric submarines and domestically built midget submarines can operate in the strait's relatively shallow waters.
• Coastal defense artillery: Shore-based rocket and artillery positions add an additional layer of threat.

This layered defense is designed to make the cost of forcing passage through the strait prohibitively high — even for the US Navy.

Historical Crises

The Strait of Hormuz has been the scene of multiple confrontations over the past four decades:

The Tanker War (1980–1988)

During the Iran-Iraq War, both sides attacked commercial shipping in the Persian Gulf in an attempt to destroy each other's oil export revenues. Over 500 vessels were damaged or sunk. The strait itself remained technically open, but transit became extremely dangerous. Insurance rates for Gulf-bound shipping soared.

Operation Earnest Will (1987–1988)

The United States intervened to protect Kuwaiti oil tankers, reflagging them under the US flag and providing Navy escorts. During this operation, the frigate USS Samuel B. Roberts struck an Iranian mine in April 1988, nearly sinking. The US responded with Operation Praying Mantis — the largest American naval engagement since World War II — sinking or damaging six Iranian vessels.

2019 Tanker Attacks

In May and June 2019, several oil tankers were attacked near the strait's approaches in the Gulf of Oman. The attacks — which included limpet mines attached to vessel hulls — were widely attributed to Iran, though Tehran denied involvement. The incidents demonstrated the ongoing vulnerability of commercial shipping in the area.

Periodic Seizures and Confrontations

Iran has periodically seized foreign-flagged tankers transiting the strait, including the British-flagged Stena Impero in July 2019. IRGC fast boats have repeatedly harassed US Navy vessels with close passes and aggressive maneuvers. These incidents, while individually contained, demonstrate Iran's willingness to use its geographic position for coercive leverage.

The 2026 Closure

On March 1, 2026, Iran formally closed the Strait of Hormuz to commercial shipping for the first time in history. The closure came simultaneously with Iran's retaliatory missile strikes on US bases across the Persian Gulf, weaponizing global energy supply as part of Iran's response to Operation Epic Fury.

The IRGC Navy deployed mines, fast attack boats, anti-ship missiles, and submarines to enforce the blockade. Within hours, patrol boats fired warning shots at a tanker attempting to transit, forcing it to reverse course. This was not a threat or a rhetorical escalation — it was the realization of a scenario energy analysts and military planners had warned about for decades.

The closure triggered an immediate spike in global oil prices past $130 per barrel and disrupted energy supply to every major importing nation. For the full analysis of the closure and its economic impact, see our detailed coverage: Iran Closes Strait of Hormuz: 20% of Global Oil Supply Disrupted.

Why It Matters for the Clock

The Strait of Hormuz sits at the intersection of energy security and nuclear risk. Its closure transforms a bilateral military conflict into a global economic crisis, drawing additional nations — particularly China, India, Japan, and South Korea — into the strategic calculus. When the world's most important energy chokepoint becomes a theater of war, the number of actors with stakes in the outcome multiplies, the pressure for military intervention increases, and the risk of miscalculation rises accordingly.