As US blocks Strait of Hormuz, Navy prepares for showdowns
As the US military announced this week that its blockade of the Iranian coast was in full force, it was also sending another US aircraft carrier, the USS George HW Bush, escorted by Navy warships, to the Middle East.
This brings about 6,000 additional troops to the region that could be used to bolster blockade efforts or to retaliate if Iran follows through on its threats of retaliation against the United States for closing its ports. The plan, U.S. officials say, is to pressure Tehran to negotiate before a shaky two-week ceasefire expires next week.
“We can do this all day,” Defense Secretary Pete Hegseth said in a press briefing Thursday.
Why we wrote this
The US military has blocked shipping in the Strait of Hormuz, hoping to force Iran to negotiate. But the blockade could pose challenges for the United States, further escalating tensions along this crucial transit route.
Whether this is true remains to be seen.
For now, American sailors are working with little respite. The USS Gerald R. Ford — commissioned from the Mediterranean to the Caribbean for the capture of former Venezuelan leader Nicolás Maduro in January and then to the Middle East in February — reached its 296th day of deployment on Wednesday, setting a post-Vietnam War record.
Meanwhile, maritime traffic passing through the strategically vital strait has fallen significantly and appears to have changed little since the blockade began on Monday, although two U.S. Navy destroyers entered the strait last week to begin mine-clearing operations.
The problem is that ships, both military and commercial, could be even more vulnerable to mines and other potential Iranian strikes when they leave the strait than when they enter it, Adm. Daryl Caudle, chief of naval operations, warned Wednesday during a discussion at the Atlantic Council. Shipowners and crews, who do not want their ships to explode, are sensitive to such eventualities.
But if peace talks move forward and shipping speeds up, the Navy could become a victim of its own success as the pace of operations makes the mission more difficult, says retired Army officer Bryan McGrath, who previously commanded one of the guided-missile destroyers now participating in Operation Epic Fury.
The Navy has not yet needed to board any ships, Gen. Dan Caine, chairman of the Joint Chiefs of Staff, said at a Pentagon briefing Thursday morning.
If they were called to do so, the blockade mission could become more complicated, Mr. McGrath said.
The Navy could, for example, ban Chinese-flagged ships carrying Iranian oil across the strait – a scenario that could become even more dangerous if the tankers were escorted by Chinese warships, he notes.
Throughout the operation, the U.S. military must adhere to strict rules of engagement and enforcement prescribed by centuries of naval tradition and by treaties surrounding blockades.
Overall, Admiral Caudle added Wednesday, “This is a major undertaking.”
Strait movements and countermoves
Some 10,000 U.S. troops, along with a dozen warships and more than 100 aircraft, are currently participating in the blockade of the Strait of Hormuz, according to U.S. Central Command, which directs U.S. military operations in the Middle East.
On Tuesday, an Iranian-flagged cargo ship attempted to escape the blockade, but a U.S. guided-missile destroyer “managed to redirect the ship, which is heading toward Iran,” the command said.
No ships have yet broken through the blockade and 10 merchant ships have obeyed instructions from US forces to turn around and return to an Iranian port in the Gulf of Oman, US Central Command added.
For now, after withdrawing most of its ships from the Persian Gulf before the start of the war, the navy is intercepting and redirecting ships in the Gulf of Oman. The Strait of Hormuz connects these two bodies of water.
About 20 miles wide at its narrowest point, the strait has even narrower shipping lanes, with a width of just two miles in each direction. As transiting ships are routed through these lanes, they become easier targets for Iran. Along its mountainous coastline are man-made “wet tunnels” where Iran’s Islamic Revolutionary Guard Corps is believed to have hidden weapons and speedboats. These weapons and boats can be used to defend Iran, but also to attack passing ships.
The U.S. Navy has its own defenses, including radar systems to detect enemy missiles and drones, as well as surface-to-air missiles and cannons to shoot them down.
The Navy is also beginning to use helicopters launched from ships and equipped with cannons capable of shooting down enemy drones. To date, “they are one of the best tools” the Navy has for defending ships against Iranian Shahed drones, Mr. McGrath said.
U.S. sailors have had plenty of practice defending against these types of weapons thanks to the Navy’s campaign against Iran-backed Houthi rebels in Yemen, who have attacked U.S. ships 174 times since 2023.
Perhaps in a nod to that threat, on its journey east to the Arabian Sea, the USS George HW Bush is diverting and skirting the African coast rather than taking the standard route through the Mediterranean and Red Sea, an effort, some analysts say, to avoid attacks by the Houthis that the group is waging in solidarity with Iran.
With high-end missiles and laser weapons that could help protect Navy ships from drones still in the development phase and fraught with problems, the Navy’s surface fleet in coming years could avoid operating in waters within range of drones and anti-ship missiles, a 2024 Congressional Research Service report warned.
Iranian missiles that severely damaged U.S. military bases in the Gulf region have also raised questions about whether the Navy’s Fifth Fleet, home to 9,000 U.S. troops, will ever return to its base in Bahrain.
Is this legal?
Despite Iran’s claims that the blockade is an act of war that could upend the ceasefire agreement, it has so far been implemented in accordance with the laws of naval warfare, said Raul Pedrozo, a professor of the law of armed conflict at the U.S. Naval War College.
The United States, because it is waging a war, “has the absolute right to stop any neutral vessel at sea to determine whether or not it is carrying contraband,” he asserts. That said, “you need to apply it carefully, because you don’t want to be accused of interfering with neutral commerce.”
For a blockade to be legal, it must also be applied impartially to friends and foes alike, Professor Pedrozo explains. This could create tensions with Chinese-flagged vessels, for example, since the state under whose flag a vessel sails – in this case China – has exclusive jurisdiction over that vessel in peacetime.
“This exclusive competence disappears during an international armed conflict,” explains Professor Pedrozo. This “could certainly strain relations with other countries.”
China’s Foreign Ministry called the US blockade “dangerous and irresponsible.”
To prevent Chinese-flagged ships from being boarded, Beijing could use its own warships to escort them, something of a challenge to American forces, Mr. Clark says.
“The United States probably won’t fire on any of these ships, right?” Doing so, he adds, would amount to “attacking a third party simply for trying to escort its oil.”
Given that the United States is unlikely to respond in this scenario, it would amount to “an opportunity to poke them in the eye,” he says.
“It’s a way to embarrass the United States that could be very beneficial for China.”
