The Strait of Hormuz has been effectively closed for almost four weeks, throwing global oil markets into turmoil, with no clear end in sight.
Iranian threats and attacks on ships in the Gulf have increased the risk of passage to the point where nearly all traffic through the narrow waterway has come to a halt. The waterway is a major conduit for about 20% of the world’s oil and natural gas, as well as the fertilizer that helps grow the crops the world depends on.
As the energy crisis deepens, US President Donald Trump has touted diplomatic efforts to lift the blockade, while considering the possibility of sending thousands of troops to the Middle East and sending the US Navy to escort oil tankers.
However, Iran still has the advantage in many ways, partly due to its unconventional methods of warfare such as cheap drones and sea mines, and partly due to geography. Taken together, these two realities make it difficult for the United States and other countries to defend their ships or secure the straits militarily.
And it is to Iran’s advantage to maintain control. Iranian authorities said they would continue to collect fees for some tankers to safely pass through the strait, after Lloyd’s List Intelligence published a report on March 23 that found at least two tankers paid large sums of money to pass through the strait.
The Strait of Hormuz is about 39 kilometers wide at its narrowest point, according to shipping analysis firm Vortexa. And almost all traffic passes through two major transportation lanes that are even more congested.
Nick Childs, senior naval and maritime security fellow at the International Institute for Strategic Studies, said: “There’s a reason this is called a choke point. There are a lot of choke points around the world. But this is a uniquely difficult problem because there are no alternatives.”
One of the challenges for ships and potential ship escort operations is that there is very limited room for maneuver.
“In the open ocean you always have the option of changing routes, but in choke points or narrow seas that option is not possible,” said Kevin Rowlands, journal editor at the Royal United Services Institute think tank. “That means Iran doesn’t necessarily have to go out and find a target. Iran can sit back and wait.”
That effectively creates a “kill zone,” he said, where the warning time for an attack can be just a few seconds.
Not to mention, Iran has about 1,000 miles of coastline from which it can launch anti-ship missiles. These missile batteries are mobile, making them difficult to eliminate, and the long Gulf line means Iran could attack far beyond the strait itself.
“The Iranian north is not flat; it has hills, mountains, valleys, urban areas and offshore islands. All of this makes it more difficult to detect looming threats and makes it easier for Iran to hide its mobile weapons systems,” Rowlands, a former director of the Royal Naval Strategic Research Center, told CNN in an email.
Analysts say Iran’s ability to damage commercial shipping through a variety of attack capabilities has declined since the war began.
“However, it is almost impossible to reduce risk to zero, and we expect ships to face residual levels of threat from some or all of these systems for some time,” Rowlands said.
Rowlands said the complex threat means any operation to escort the ship would likely require much more than a traditional military convoy moving in front of or behind the tanker.
“Naval missions are likely to employ a defense-in-depth approach with surveillance by satellites, patrol aircraft and drones. Ships may follow specific mine-cleared routes,” he said.
Childs said the United States has succeeded in reducing many of Iran’s conventional naval capabilities. But the biggest threat still comes from Iran’s unconventional weaponry, including drones, small fast-attack vessels, and even unmanned boats loaded with explosives.
“If the Iranians decide to mine a mine, they can roll it off the back of a seemingly harmless dhow,” Childs told CNN. “The US is probably talking about Iran’s main submarine, but there could probably be ‘mini-submarines’ that we still need to think about,” he added, referring to mini-submarines that can operate in shallow waters.
U.S. allies, including the United Kingdom, France, and Bahrain, are also working to develop viable plans to protect international shipping on waterways.
What is the situation now?
Iran attacked at least 19 ships near the Strait of Hormuz, the Persian Gulf, and the Gulf of Oman.
And analysts say Iran doesn’t even need to destroy the ships to achieve its goal of disrupting global energy trade. As long as the threat is high enough, shipping companies are unlikely to risk restarting shipping. However, some ships with ties to Iran, China, India and Pakistan have passed through the strait.
Iran said “non-hostile vessels” could pass through the strait if they cooperated with Iranian authorities. A report from Lloyd’s List intelligence agency said at least 16 ships were passing through, including one ship believed to have paid a $2 million fee, as well as several “zombie” tankers using false names of dismantled ships. CNN cannot independently verify reports.
Even if all tanker traffic eventually resumes, it will take time to clear the backlog. According to the International Maritime Organization, nearly 2,000 ships are trapped in the Persian Gulf.
The Trump administration has billed it as a diplomatic breakthrough. Iran, on the other hand, has acknowledged exchanging messages through an intermediary but insists it is not negotiating with the United States.
President Trump’s talk of negotiations comes as thousands more U.S. Marines and sailors are heading to the Middle East.
Two U.S. officials told CNN earlier this week that the 11th Marine Expeditionary Unit and Boxer Amphibious Ready Group were on their way. US officials have also previously told CNN that a Marine Expeditionary Unit (MEU) from the amphibious assault ship Tripoli is being deployed to the Middle East, but did not specify where it would be deployed or what operations it would be used for.
These MEUs have typically been used for missions such as evacuations and amphibious operations that require ship-to-shore movement, such as raids and assaults. This has led to increased speculation about the possibility of a ground operation, although the Trump administration has so far said it has ruled out a ground operation in Iran.
Military analysts said the United States may be counting on the fact that bringing the USS Tripoli and other maritime assets into the region to pose a threat may be enough to change Iran’s calculations.
President Trump has also threatened to attack more oil trade-related sites if Iran continues to close the Strait of Hormuz. Last Friday, the US military attacked a military facility on Kharg Island, which handles about 90% of the country’s crude oil exports. No government-controlled sites linked to oil trading on the island were attacked, but President Trump warned they could be next and could spark further escalation.
