EXPLAINER
Iranian lawmaker says Tehran considering closing waterway, described as ‘world’s most important oil transit chokepoint’.
Iran is considering closing the Strait of Hormuz, Iranian news agency IRINN has reported, citing key conservative lawmaker Esmail Kosari, as the conflict with Israel intensifies.
The move would send oil prices soaring and risk expanding the war. So what is the strategic waterway and why is it vital to global trade?
Hormuz is the only marine entryway into the Persian Gulf. It splits Iran on one side and Oman and the United Arab Emirates on the other, and it links the Persian Gulf to the Gulf of Oman and the Arabian Sea in the Indian Ocean.
According to the US Energy Information Administration, about 20 percent of global oil consumption flows through the strait, which the agency describes as the “world’s most important oil transit chokepoint”. At its narrowest point, it is 33km (21 miles) wide, but shipping lanes in the waterway are even narrower, making them vulnerable to attacks and threats of being shut down.
During the Iran-Iraq conflict between 1980 and 1988, which killed hundreds of thousands on both sides, both countries targeted commercial vessels in the Gulf in what became known as the Tanker War, but Hormuz was never completely closed.
More recently, in 2019, four ships were attacked near the strait off the coast of Fujairah, UAE, amid heightened tensions between Iran and the United States during Donald Trump’s first presidency. Washington blamed Tehran for the incident, but Iran denied the allegations.
Attacking shipping lanes has long been used to apply pressure amid conflict. Since the outbreak of the war in Gaza, the Houthis in Yemen have been attacking ships around Bab al-Mandeb Strait, the entryway into the Red Sea on the other side of the Arabian Peninsula.
While the Houthi campaign has affected global commerce, ships can avoid the Red Sea by sailing around Africa – a longer but safer journey. However, there is no way to ship anything by sea out of the Gulf without going through Hormuz.
Even countries that do not import petrol from Gulf countries would be affected if the strait were to be closed because a major drop in supply would spike the price per barrel on the global market.
Despite the Iranian lawmaker’s threat, it is unclear whether Iran has the ability or willingness to shut down the strait.
Such a move would almost certainly invoke retaliation from the US, which has naval military assets in the region.
After Israel launched a wave of attacks across Iran early on Friday, targeting military leaders, residential buildings, army bases and nuclear sites, Iran responded with hundreds of ballistic missiles.
Although the US helped shoot down the Iranian missiles, Washington has not directly attacked Iran. US officials have stressed that Washington was not involved in the Israeli strikes.
Tehran has not targeted US troops or interests in the region, either.
Closing Hormuz, however, would hit Americans in the wallet and could spark a military response from Trump.
While an Iranian move against the strait may not be imminent, Kosari’s comments underscore that attacking shipping lanes is a card that Tehran may play amid the hostilities.
In April 2024, Iranian armed forces seized a container ship near the Strait of Hormuz amid rising tensions across the region after a deadly Israeli attack on Iran’s consulate in Damascus, Syria. A limited Iranian strike on Israel in response was followed by an Israeli one on Iran. At the time, they were the most serious direct military exchanges between the two foes.