If the United States assumed, before attacking Iran, that the major oil producer would be reluctant to close the Strait of Hormuz for fear of blocking its own oil exports, it miscalculated.

Traffic through the strait, through which a fifth of the world’s oil output normally flows, has been severely curtailed since the start of the latest Middle East conflict two weeks ago. At least 16 vessels in the region have been struck by drones or other weapons, with Iran claiming responsibility for some of the attacks.

But Iran itself is shipping oil through the strait in almost the same volumes as before the war, earning the much-needed cash to sustain its economy and war effort. In addition, there were already millions of barrels of Iranian crude oil at sea looking for buyers before the conflict began.

Tanker tracking data and satellite images show that Iranian crude has flowed through the strait even as the conflict has crippled exports of crude and natural gas from nearby Persian Gulf countries.

Energy analysts at trade data and analytics company Kpler estimated Thursday that Iran had been able to export 12 million barrels since the conflict began on February 28. Maritime intelligence company TankerTrackers has an even higher estimate: 13.7 million barrels as of the middle of last week.

Those figures would suggest that Iran is managing to ship about 1 million barrels per day (bpd). That compares with its average exports of 1.69 million bpd last year, according to Kpler’s data.

The United States appears to have made no effort to halt Iranian tankers, even as it has destroyed much of Iran’s navy. The United States has also largely avoided hitting oil infrastructure such as refineries, pipelines and storage tanks – although Israeli strikes have seriously damaged storage tanks around the capital, Tehran.

Almost all Iranian oil is exported from deep-water berths on Kharg Island, some 30 kilometers (20 miles) off the Iranian coast. There were intense US strikes Friday against military targets on the island but not its oil infrastructure.

Trump later warned he would reconsider the decision not to target oil facilities on Kharg, which is about one-third the size of Manhattan, if Iran continued to obstruct the passage of ships in the Strait of Hormuz.

Asked by CNN Sunday whether Trump was prepared to target oil facilities on Kharg, the US ambassador to the United Nations, Mike Waltz, said the president was “not going to take any options off the table… I would certainly think he would maintain that optionality if he wants to take down their energy infrastructure.”

For now, Washington is “fine” with some Iranian as well as Indian and Chinese ships getting through the Strait of Hormuz, US Treasury Secretary Scott Bessent said in a CNBC interview Monday.

Kharg’s oil infrastructure was still operational Saturday, according to TankerTrackers. The company said that, according to satellite images, all 55 crude oil storage tanks on the island appeared to be intact, and two Iranian tankers were loading 2.7 million barrels of crude oil Saturday.

In reality, there could be more Iranian tankers setting off from the island. It’s difficult to monitor the vessels’ movements as they frequently turn off their transponders – used to communicate their location – to evade Western sanctions. For example, maritime intelligence group Windward said six Iranian VLCCs, or very large crude carriers, were on Friday operating with their transponders off or broadcasting deceptive locations while at Kharg.

In addition to Iran’s crude still being exported through the Strait of Hormuz, vast amounts of its oil were already on tankers in the world’s oceans before the conflict began, looking for buyers. Vortexa, an energy data firm, estimated that roughly 170 million barrels of Iranian oil were at sea in January.

Perhaps anticipating US and Israeli strikes, Iran turbo-charged oil exports in February. Windward said the average daily volume leaving Kharg in February was 2.04 million barrels. That presents a jump of around a quarter compared with the average figure last year.

According to Iran’s semi-official Fars news agency, Iran has also been able to increase its natural gas exports. It quoted Iraq’s electricity ministry as saying that natural gas imports from Iran last week tripled to 18 million cubic meters per day.

It appears that Tehran is also using its command of the Strait of Hormuz as a bargaining chip in its relations with countries thirsty for Middle Eastern oil, especially Asian customers.

“The Strait of Hormuz is open, it is only closed to the tankers and ships belonging to our enemies, to those who are attacking us and their allies. Others are free to pass,” Iranian Foreign Minister Abbas Araghchi said on the weekend.

India freed three Iranian oil tankers that had been seized last month to secure Iran’s permission for two Indian vessels to pass through the Strait of Hormuz, according to the Iranian newspaper Sharq, which also reported negotiations to resolve “issues related to maritime security and oil trade between the two countries.”

India’s shipping ministry confirmed to CNN that two vessels, both carrying liquid petroleum gas from the Gulf region, had safely transited the Strait of Hormuz overnight Friday into Saturday.

India’s foreign minister S Jaishankar told the Financial Times on the weekend that the negotiations that allowed the Indian tankers to pass through the strait were an example of what diplomacy could bring.

“I am at the moment engaged in talking to them and my talking has yielded some results,” he said. “Certainly, from India’s perspective, it is better that we reason and we co-ordinate and we get a solution than we don’t.”

Iran is also considering allowing a limited number of oil tankers to pass through the strait provided the oil cargo is traded in Chinese yuan, a senior Iranian official told CNN last week. Oil is almost entirely traded in dollars, apart from sanctioned Russian oil, which is traded in rubles or yuan.

China has attempted to make inroads for the past several years to buy oil in yuan, particularly in Saudi Arabia, but with limited success.

In the long run, Iran needs the Strait of Hormuz as much as its neighbors do, and its ships are also vulnerable to interception in and around the narrow waterway should the United States seek to do so.

Iran has very limited overland routes for exporting its oil, with far less capacity to use ports outside the currently dangerous Persian Gulf than Saudi Arabia (which has the port of Yanbu on the Red Sea) or the United Arab Emirates (which has Fujairah in the Gulf of Oman). (CNN)

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