A waterway barely 21 nautical miles wide at its narrowest carries a large share of the world's oil and gas. Here is what it is, where it sits, and why it matters.
Last updated: October 2026
The Strait of Hormuz is a narrow waterway connecting the Persian Gulf to the Gulf of Oman and the Arabian Sea. To its north lies Iran; to its south lie Oman and the United Arab Emirates. At its narrowest point it is roughly 21 nautical miles wide, and the shipping lanes that tankers actually use are narrower still — two lanes, one in each direction, each about two miles wide, separated by a buffer zone.
Its importance comes from what passes through it. The Persian Gulf is home to several of the world's largest oil and gas producers, including Saudi Arabia, Iraq, the United Arab Emirates, Kuwait, Qatar, and Iran. Much of what they export must leave by sea, and the only sea exit from the Gulf is Hormuz. Roughly a fifth of the world's petroleum liquids transit the strait, along with a large share of liquefied natural gas — including most of Qatar's LNG exports. There is no alternative sea route out of the Gulf. A tanker leaving the Gulf either passes Hormuz or it does not leave.
Hormuz matters because the world economy runs on energy that flows through it, and because the strait is narrow enough to be threatened. A closure — or even the credible threat of one — moves oil prices within hours, because traders price in the risk of lost supply. The 2019 attacks on tankers near the strait showed that the waterway does not have to close for the world to pay: insurance premiums rose, shipping costs rose, and oil prices jumped, all without a single day of full closure.
The strait also matters because it sits in one of the world's most contested regions. Iran borders the strait to the north and has repeatedly threatened to close it in response to sanctions or military pressure. The United States maintains a naval presence in the region, including the Fifth Fleet headquartered in Bahrain, in part to keep the waterway open. The strait's security is therefore not only an energy question but a standing military and diplomatic one.
Only partly. Saudi Arabia and the United Arab Emirates have built pipelines that bypass Hormuz, carrying some oil to the Red Sea and the Gulf of Oman respectively. These pipelines reduce dependence at the margin, but they carry a fraction of what tankers carry, they are themselves vulnerable in wartime, and they cannot carry liquefied natural gas. Qatar, the world's great LNG exporter, has no pipeline alternative at all. For the foreseeable future, Hormuz remains the Gulf's door to the world.
It connects the Persian Gulf to the Gulf of Oman and the Arabian Sea. Iran lies to its north; Oman and the United Arab Emirates lie to its south. At its narrowest it is roughly 21 nautical miles wide.
Roughly a fifth of the world's petroleum liquids transit the strait, along with a large share of global liquefied natural gas. Exact shares vary by year and by measure, but the strait is consistently the world's most important oil chokepoint.
It has been threatened many times and contested — notably during the Iran-Iraq war's Tanker War in the 1980s — but a full, sustained closure has never been carried out. The threat alone is usually enough to move markets.
No single country. Iran borders it to the north, Oman to the south, and the United States and other naval powers patrol the region. Freedom of navigation through the strait rests on a mix of international law, deterrence, and diplomacy.
