President Trump's announcement that the U.S. military would blockade the Strait of Hormuz sets up a risky new showdown that could draw American forces into a prolonged struggle to control the strategic chokepoint while compounding the global economic damage caused by the conflict.
Hours after U.S. peace talks with Iran broke down in Pakistan, Trump said that the Navy would begin the blockade, "seek and interdict" vessels that had paid Iran to get through the strait, and then start clearing the waterway of sea mines. "He added that any Iranian forces that fired on U.S. troops or commercial shipping would be "BLOWN TO HELL."
The blockade is set to begin Monday at 10 a.m. Eastern Time, according to U.S. Central Command. The move comes after Vice President JD Vance ended 21 hours of talks in Islamabad without an agreement, blaming Tehran for refusing U.S. terms on its nuclear program.
While the U.S. military has the resources and the capabilities to execute such a blockade, current and former U.S. officials and analysts say that sustaining control of the waterway could be far more difficult.
"It's certainly well within the capacity of the forces that are there to mount a blockade," said Bryan Clark, a retired naval officer and senior researcher at the Hudson Institute. "Now, if Iran starts shooting at them or shooting at people that are operating these systems, then obviously it gets more difficult...You have to protect them with ships."
The move opens a volatile new phase in the six-week conflict, shifting from punishing strikes on military targets to an open-ended campaign to police the strait. The prospect of such a blockade could set off a high-stakes battle that tests which side has the higher threshold for pain -- Tehran or global markets.
Current and former U.S. defense officials also say the blockade would buy the U.S. time to sweep mines and establish a protected passage for commercial shipping, but any renewed Iranian attacks would quickly complicate the mission.
The Pentagon referred questions about the blockade and how it would be enforced to the White House. "The United States Navy is the greatest in the world and has more than enough resources to sustain the blockade," White House spokeswoman Olivia Wales said. "The President is leveraging the strength of our U.S. Navy to secure the Strait of Hormuz, end Iran's extortion, and send a clear message that the United States will never allow Iran to have a nuclear weapon."
The narrow waterway is exposed to Iran's coastline, and any operations there will remain vulnerable to mines, drones and attack boats. While Trump has repeatedly touted the U.S. military's decimation of Iran's navy, the paramilitary Islamic Revolutionary Guard Corps still maintains much of its extensive fleet of more nimble speedboats that it uses to control the strait. More than 60% of those fast-attack craft and speedboat vessels remain intact and continue to pose a threat, according to Farzin Nadimi, an Iran-focused senior fellow with the Washington Institute, a U.S.-based think tank.
"This is a militarily manageable effort," said Mark Montgomery, a retired Navy rear admiral and senior fellow at the Foundation for Defense of Democracies. And the operation could be effective even if U.S. forces don't stop every vessel, just enough ships to "spook the herd" and scare off other shadow-fleet operators to turn up the economic pressure on Iran, which is now heavily dependent on those shipments. "But I don't think you could do this alone."
While Trump said on Sunday that "numerous countries" would be helping U.S. forces impose the blockade, it was still unclear what such a coalition would look like. Some European and Persian Gulf officials had previously signaled support for a multinational effort to restore free passage through the strait, though some key countries said this would depend on a lasting cease-fire and an international mandate.
"The de-escalation window for the global economy, such as it was, is over for now," said Rachel Ziemba, an adjunct senior fellow at the Center for a New American Security, a Washington-based think tank. "Iran is betting they can hold out longer than the U.S. and the global economy."
The oil shock of Iran paralyzing the strait is already rippling through Asia, where factories are curbing production to save energy and some gas stations are rationing fuel. Some airports across Asia and Europe are beginning to run out of jet fuel, and it could take months for inventories to recover. For countries in the Gulf, the economic damage is shaping up to be the worst in decades, eclipsing the pandemic. Researchers at Capital Economics forecast Qatar's gross domestic product to shrink by 13% this year, the United Arab Emirates's by 8% and Saudi Arabia's by 6.6%.
"I don't think the rest of the world is ready to face an attrition reality," Ziemba said. "We are already seeing pain and damage."
Choking off Iran's ability to export its crude would hit an already battered economy. But having successfully shipped crude throughout the conflict, Tehran is cushioned by the recent windfall profits, at least in the short term. Tehran also retains potent leverage against the global economy. If cornered, it could cripple the Gulf's fallback options by striking Saudi and U.A.E. bypass pipelines, while its regional proxies could attempt to close the critical Bab al-Mandeb shipping route off Yemen.
Meanwhile, the blockade would tighten the already challenging supply-and-demand equation for the global oil market, threatening to drive prices sharply higher. The U.S. war in Iran so far has blocked around 13 million barrels a day of oil production from the Gulf, or some 12% of the global market, according to oil-market researcher Rory Johnston. If the U.S. successfully blocks Iranian sales -- exports Tehran has managed to sustain throughout the conflict -- it would strip the global balance of another roughly 2 million barrels a day.
"It's been strange to see Iran continue to export through the war, but it, too, will come at an additional cost to the global economy starved by the Hormuz stoppage," Johnston said.
Trump on Sunday conceded that energy prices might not fall soon and could be higher around the time U.S. voters head to polls in midterm elections this fall. Asked on Fox News if he thinks oil and gas will be lower then, Trump said: "I hope so. I mean, I think so. It could be...or maybe a little bit higher. It should be around the same. I think this won't be that much longer."
The large U.S. Navy presence outside the Strait of Hormuz will give Trump the ability to choke off traffic and interdict oil tankers, analysts say. The aircraft carrier USS Abraham Lincoln, which is in the Arabian Sea, could serve as a base of operations for boardings. The U.S. had eight guided-missile destroyers in the region at the start of the conflict, which could be used to block or influence the movement of oil tankers that try to flee the Gulf.
Destroyers would also be used to bat down aerial threats should Iran mount attacks on U.S. ships. The warships proved their ability to counter waves of drone-and-missile attacks while defending against Houthi barrages in the Red Sea last year. However, the geography of the Gulf is much tighter than the Red Sea, and the warships would have less time to respond if Iran fires from the shore of the islands it controls, analysts say.
The U.S. could also enlist the help of the Coast Guard or special-operations forces to carry out tanker seizures. The Coast Guard, which falls under the Department of Homeland Security, has law-enforcement authority to interdict ships in international waters. It remains unclear what would happen to the ships that the U.S. military intercepts.
While the fragile cease-fire agreed to on April 7 was tied to Tehran pausing its own blockade and providing safe passage through the Strait, it didn't lead to a real reopening of the waterway. Following the deal, Iranian officials warned via marine radio that any ships that try to cross without permission from the Revolutionary Guard risk being destroyed. Iran told mediators that it would limit crossings to about a dozen ships a day, down from more than 100 before the war.
But the arrangement quickly unraveled. While a handful of ships was able to transit, hundreds were stuck in the Gulf.
Rather than seize tankers in the Middle East, which could strain U.S. forces already exhausted by six weeks of war, the U.S. could also wait to board ships until they enter other bodies of water. The Pentagon showed its willingness to hunt down tankers in the Atlantic and the Indian Ocean this year when it took control ships that had fled Trump's blockade of Venezuela.
"You saw what we did with Venezuela. It'll be something very similar to that, but at a higher level," Trump told Fox News on Sunday. "It'll take a little while, but it'll be effective pretty soon."