As the U.S. military announced this week that its blockade of the Iranian coast is in full effect, it was also sending another U.S. aircraft carrier, the USS George H.W. Bush, escorted by Navy warships, to the Middle East.
That brings roughly 6,000 more troops to the region who could be used to bolster blockade efforts or to strike back if Iran makes good on its threats to retaliate against the United States for closing its ports. The plan, as U.S. officials see it, 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
America’s military has choked off shipping in the Strait of Hormuz, hoping to force Iran to negotiate. But the blockade could pose challenges for the U.S., further escalating tensions along the critical transit route.
Whether that is true remains to be seen.
For now, U.S. sailors are working with little respite. The USS Gerald R. Ford – ordered from the Mediterranean to the Caribbean for the capture of former Venezuelan leader Nicolás Maduro in January, then to the Middle East in February – reached its 296th day of deployment Wednesday, setting a post-Vietnam War record.
Ship traffic through the strategically vital strait, meanwhile, has dropped significantly and appears little changed since the blockade began Monday, even as two U.S. Navy destroyers entered the strait last week to start mine-clearing operations.
The problem is that vessels, both military and commercial, could be even more vulnerable to mines and other potential Iranian strikes when leaving the strait than when coming into it, Adm. Daryl Caudle, Chief of Naval Operations, warned Wednesday in a discussion at the Atlantic Council. Shipowners and crews, who don’t want their ships blown up, are sensitive to such possibilities.
But if peace talks progress and vessel traffic picks up, the Navy could become a victim of its own success, as the pace of operations compounds the difficulty of the mission, says retired Navy officer Bryan McGrath, who previously commanded one of the guided-missile destroyers now taking part 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 during a Pentagon briefing Thursday morning.
Should they be called upon to do that, though, the blockade mission could get more complicated, Mr. McGrath says.
The Navy could, for example, interdict Chinese-flagged vessels carrying Iranian oil through the strait – a scenario that could grow even more fraught were the tankers to be escorted by Chinese warships, he notes.
Throughout the operation, the U.S. military must navigate the strict rules of engagement and enforcement prescribed by centuries of Navy tradition and treaties surrounding blockades.
All together, Admiral Caudle added Wednesday, “This is a major undertaking.”
Strait moves and countermoves
Some 10,000 U.S. troops, along with a dozen warships and more than 100 aircraft, are currently taking part in the Strait of Hormuz blockade, according to U.S. Central Command, which runs U.S. military operations in the Middle East.
On Tuesday, an Iranian-flagged cargo vessel tried to evade the blockade, but a U.S. guided missile destroyer “successfully redirected the vessel, which is heading back to Iran,” the command said.
No ships have yet broken through the blockade, and 10 merchant vessels complied with direction from U.S. forces to turn around and reenter an Iranian port on the Gulf of Oman, U.S. Central Command added.
For now, having withdrawn most of its ships from the Persian Gulf before the war began, 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 shipping lanes that are narrower still, with a width of just some two miles in each direction. As transiting ships are funneled into 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. Those arms 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, and surface-to-air missiles and guns to shoot them down.
The Navy is also starting to use helicopters launched from ships and equipped with guns that can shoot down enemy drones. To date, “these have been one of the best tools” the Navy has for defending ships against Iran’s Shahed drones, Mr. McGrath says.
U.S. sailors got plenty of practice defending against these sorts of weapons through the Navy’s campaign against Iran-backed Houthi rebels in Yemen, who have attacked U.S. ships 174 times since 2023.
Perhaps as a nod to this threat, in its travels east to the Arabian Sea, the U.S.S. George H.W. Bush is diverting and going around the coast of Africa rather than taking the standard route through the Mediterranean and Red Seas, an effort, some analysts say, to avoid Houthi attacks that the group carries out in solidarity with Iran.
With missiles at a premium and laser weapons that could help protect Navy ships against drones still in the development stages and fraught with glitches, the Navy’s surface fleet in the coming years might avoid operating in waters within range of drones and anti-ship missiles, a 2024 Congressional Research Service report warned.
Iranian missiles that left U.S. military bases in the Gulf region badly damaged have raised questions as well about whether the Navy’s Fifth Fleet, home to 9,000 U.S. personnel, will ever return to its base in Bahrain.
Is it legal?
Despite Iran’s claims that the blockade is an act of war that could upend the ceasefire deal, it has so far been carried out in keeping with the laws of naval warfare, says Raul Pedrozo, professor of the law of armed conflict at the U.S. Naval War College.
The U.S., because it is fighting a war, “has the absolute right to stop every neutral vessel at sea to determine whether or not it’s carrying contraband,” he argues. That said, “You have to apply it cautiously, because you don’t want to be accused of interfering with neutral trade.”
For a blockade to be legal, it must also be impartially applied to friends and foes alike, Professor Pedrozo says. This could create tensions with Chinese-flagged vessels, for example, since the state under whose flag a ship sails — in this case, China — has exclusive jurisdiction over that vessel in times of peace.
“That exclusive jurisdiction goes away during an international armed conflict,” Professor Pedrozo says. This “definitely could strain relationships with other countries.”
The Chinese foreign ministry has pronounced the U.S. blockade “dangerous and irresponsible.”
To avoid having Chinese-flagged ships boarded, Beijing could use its own Navy warships to escort them, in a sort of dare to U.S. forces, Mr. Clark says.
“The U.S. probably won’t shoot on any of these ships, right?” Doing so, he adds, would amount to “attacking a third party just for trying to escort its oil out.”
Given that the United States would be unlikely to respond in this scenario, it would amount to “an opportunity to poke the U.S. in the eye,” he says.
“It’s a way of embarrassing the U.S. that could be really beneficial for China.”