The US naval blockade of Iran has started, aiming to pressure Tehran economically. Analysts warn that this blockade could significantly harm Iran's economy, particularly its oil revenue.
Key points
US naval blockade of Iran has begun
Blockade aims to pressure Tehran economically
Iran's armed forces call the blockade illegal
Blockade could significantly harm Iran's economy
Impact on Iran's oil revenue is a major concern
United StatesIranDonald Trump
The United States naval blockade of Iran has come into effect as President Donald Trump’s administration tries to pressure Tehran into accepting its terms for an end to their war by trying to squeeze the Iranian economy.
The blockade began at 14:00 GMT on Monday. Iran’s armed forces have called it “an illegal act” that “amounts to piracy”.
Even though Iran has become accustomed to US sanctions and has continued to function during the war, a blockade like this could inflict significant damage to Iran’s economy, analysts said.
How much can this blockade hurt Iran? Here’s what we know:
How will the blockade hurt Iran’s oil revenue?
Iran primarily exports oil and gas through its ports. Soon after the start of the US-Israel war on Iran on February 28, authorities in Tehran announced what amounted to a closure of the Strait of Hormuz, the only waterway out of the Gulf, through which 20 percent of the world’s oil and gas supplies pass in peacetime.
The near-shutdown of the vital chokepoint sent global oil and gas prices soaring, and since then, Iran has controlled the strait: Only ships from a few countries that struck individual deals with Tehran were allowed through.
But throughout that period, Iran itself continued to export its energy products through the strait.
Iran’s oil exports through the Strait of Hormuz account for about 80 percent of its total exports. According to Kpler, a trade intelligence firm, Iran exported 1.84 million barrels per day (bpd) of crude oil in March and has shipped 1.71 million bpd so far in April, compared with an average of 1.68 million bpd in 2025.
In other words, Iranian exports through the strait actually increased in March and early April.
From March 15 to April 14, it exported 55.22 million barrels of oil. The price per barrel of Iranian oil – across its three major variants, known as Iranian light, Iranian heavy and Forozan blend – has not fallen below $90 per barrel over the past month. On many days, the price has actually surpassed $100 a barrel.
Even at the conservative estimate of $90 a barrel, Iran would have earned $4.97bn over the past month from oil exports.
By contrast, in early February before the war started, Iran was earning about $115m a day from its crude oil exports, or $3.45bn in a month.
Simply put, Iran has earned 40 percent more from oil exports in the past month than it did before the war.
But now, with the US military blockading Iran’s ports and the Strait of Hormuz, Tehran’s capacity to export crude oil has been directly hit – and dramatically so, experts said.
“Iran would not be able to export oil, at least not at the same level,” Mohamad Elmasry, professor at the Doha Institute for Graduate Studies, told Al Jazeera before referring to Tehran’s reported from non-Iranian vessels it is allowing to pass through the strait. “The Iranians also wouldn’t be able to get tolls.”
Q&A
What are the effects of the US naval blockade on Iran's economy?
The US naval blockade is expected to significantly damage Iran's economy by restricting its oil revenue.
When did the US blockade of Iran begin?
The US naval blockade of Iran began at 14:00 GMT on Monday.
How has Iran responded to the US blockade?
Iran's armed forces have labeled the blockade as 'an illegal act' and 'piracy'.
What are the potential consequences of the blockade for Iran's oil revenue?
The blockade could severely impact Iran's oil revenue, which is crucial for its economy.
Frederic Schneider, a nonresident senior fellow at the Middle East Council on Global Affairs, agreed.
He told Al Jazeera that the previous six weeks had been a boon for Iran in terms of oil revenues, but with the US blockade, that will change.
“Iran has some buffer in the form of crude oil reserves in floating tanks, basically parked tankers, which was estimated at about 127 million barrels in February. But that doesn’t mean that the blockade wouldn’t hurt Iran.” he said.
According to the maritime intelligence agency Windward, as of Monday, total Iranian oil on the water was about 157.7 million barrels. Of this, 97.6 percent was destined for China.
Windward warned that all of this oil could be impacted by the US blockade.
Will trade of other goods be impacted?
Besides oil, the US blockade of Iranian ports could also impact Tehran’s trade of other goods.
Some key exports shipped through its ports include petrochemicals, plastics and agricultural products that primarily go to countries like China and India while major imports include industrial machinery, electronics and food, primarily sourced from China, the United Arab Emirates and Turkiye.
According to a February 18 report by the Tehran Times, data released by Iran’s Customs Administration showed that the country’s total nonoil trade reached $94bn from March 21, 2025, to January 20 with imports outpacing exports, resulting in a trade deficit.
The current blockade will impact Iran’s overall trade and hurt its economy, analysts said.
Schneider said that if nonhydrocarbon trade is disrupted, that will not only be a blow to revenues but also to supplies and lead to increased domestic shortages in an economy that has already been under a lot of strain from pre-war sanctions.
“The question will be whether this increased suffering will force Iran to concede defeat or whether it will harden its resolve and escalate the situation. But I doubt this blockade will come into full effect or last very long,” he said.
Are there alternate routes Iran can explore?
Yes. To reduce dependency on straits like the Strait of Hormuz from the Gulf and the Strait of Malacca in Southeast Asia, both of which are crucial to global trade, Iran and China have developed a railway line.
Using existing railway lines across Central Asian countries like Kazakhstan, Uzbekistan and Turkmenistan, a freight train carrying commercial goods from China first arrived in Iran in February 2016. Then in May, according to Iran’s Tasnim news agency, the first freight train from Xi’an, China, arrived at the Aprin dry port in Iran, marking the official launch of a direct rail link between Iran and China.
According to a report by geopolitical consulting agency SpecialEurasia, the China-Iran railway “helps mitigate the risks of naval interdiction by Western forces that hamper Iranian trade, particularly the transport of crude oil by Tehran’s so-called ‘ghost ships'”.
“Dark ships” or “ghost ships” operate by switching off their automatic identification system to avoid detection and circumvent sanctions. Throughout the war on Iran, shipping data have detected the presence of such ships transporting oil and other goods.
“Nevertheless, it is important to note that transporting hydrocarbons by rail involves considerable logistical challenges,” the SpecialEurasia report added.
There is currently no credible evidence that oil has been transported by rail from Iran to China.
Schneider said that if the blockade persists, it will certainly hurt Iran’s economy. But, he added, it is also unclear how long the standoff over the Strait of Hormuz will last.
“It’s very difficult to say how serious the US is about this blockade, how long it will last, how it will end and what is coming next,” he said.
There’s also an X factor: China.
“Most of the Iranian tankers are headed for China, and I cannot see China giving in to this blockade,” Schneider said. “Secondly, I don’t see the US Navy seizing or even sinking these ships.”
“So this is a very volatile situation that will quickly veer into one direction which could be a ceasefire and detente or the other which could be the escalation and the resumption of bombings and missile strikes,” he added.
