The U.S. Navy is now stopping vessels in the Strait of Hormuz, and the central question isn’t whether it can be done. It’s whether Washington can keep it up long enough to actually break Tehran.
CENTCOM announced Sunday that it would intercept all ships moving to and from Iranian ports while letting traffic from other Persian Gulf ports pass. The target is Iran’s oil exports, which the White House has identified as the country’s primary revenue source. President Donald Trump has been blunt: cut the oil, cut the money, force a change in behavior.
Not everyone agrees the word “blockade” even fits what’s happening. Bryan Clark, a senior fellow at the Hudson Institute, told reporters the operation looks more like a naval quarantine, because “the U.S. is only stopping traffic that’s coming from Iran.” That’s not just semantic hairsplitting. The legal and strategic implications of a quarantine versus a blockade differ significantly, though Iran’s oil shipments don’t care what label Washington uses.
The economics are straightforward, at least in theory.
Eric Schuck, an economics professor at Linfield University in Oregon, says the strategy follows a pressure model that’s well-documented in the academic literature. You don’t need to destroy an economy outright. You need to find a chokepoint that’s so embedded in how the whole system functions that everything downstream stops when you block it. “Something which is nonsubstitutable, something that is so essential to their economy that everything else is going to come to a halt,” Schuck said. For Iran, that’s oil, and according to U.S. Energy Information Administration data, the country’s petroleum exports have been its dominant foreign revenue source for years. Schuck described the naval operation as a harder-edged extension of the sanctions framework Washington’s had in place against Iran for decades.
Getting it to work is where history gets uncomfortable.
Naval blockades have always been expensive to run. Britain’s blockades of French ports during the Napoleonic wars tied up a disproportionate share of the Royal Navy’s ships, and fast French vessels still got through with regularity. Blockade runners are a constant in every major maritime standoff, from the American Civil War to the two World Wars. Historical accounts compiled by the International Committee of the Red Cross document how even well-resourced naval powers struggled to make blockades airtight.
The Strait of Hormuz is 21 miles wide at its narrowest point. That’s narrow enough to concentrate monitoring, but it’s still a high-traffic corridor that handles roughly 1.5 million barrels of Iranian oil per day at peak export levels, alongside enormous volumes of non-Iranian cargo. Identifying every vessel, assessing its origin and cargo, and making interdiction decisions in real time around the clock is a substantial operational ask.
The U.S. Navy does have tools that Britain’s admirals couldn’t have imagined. Steve Dunn, the author of “Blockade: Cruiser Warfare and the Starvation of Germany in World War One,” put the technological gap plainly. “Detection of vessels is much easier, with satellite, planes and drones and radar,” Dunn said. Helicopters and fast patrol boats can move to intercept quickly once a vessel is flagged. The USS Abraham Lincoln carrier strike group is already operating in the region, as LAist has reported, with guided-missile destroyers providing additional coverage.
But Iran’s export capacity gives it some cushion. The country was producing roughly 3 million barrels per day before the operation began, and even with significant disruption, it’s moved as much as 800,000 to 400,000 barrels per day through back-channel buyers willing to absorb the legal and financial risk of sanctions exposure. China has historically been the largest absorber of sanctioned Iranian oil.
What the U.S. is betting on is that a visible naval presence at the Strait changes the calculus for those buyers. It’s one thing to quietly purchase discounted Iranian crude when the main enforcement mechanism is financial penalties. It’s another when there’s a carrier strike group parked at the exit ramp.
Whether that’s enough pressure to move Tehran is the question no one in Washington can answer with confidence right now.