The Strait of Hormuz, a narrow, 21-mile-wide channel of water through which a fifth of the world’s traded oil and natural gas normally passes, has become the defining front in the war between the United States and Iran, a battle over who controls the waterway that has closed it to most commercial traffic, sent crude oil prices surging, and brought Washington and Tehran to the edge of a full rupture just weeks after they signed what was billed as a peace deal.
US President Trump declared Monday that the United States would henceforth be known as the “Guardian of the Hormuz Strait,” reinstating the naval blockade of Iranian ports lifted under last month’s ceasefire and announcing a 20 per cent toll on all cargo transiting the waterway. “The Hormuz Strait is OPEN, and will remain OPEN, with or without Iran,” he wrote on Truth Social.
“We are reinstating THE IRANIAN BLOCKADE.” Iran’s response came within hours: its joint military command said the US had “no role in determining the future” of the strait and would not be permitted to intervene in its management.
The exchange marked the most dramatic public escalation yet between the two countries since their ceasefire agreement collapsed under the weight of repeated violations, competing claims of sovereignty, deadly attacks on Gulf shipping, and the funeral of a slain supreme leader whose mourners openly called for the American president’s death.
Whether a last-minute Pakistani proposal for a two-week pause can pull both sides back from the brink before a Trump-imposed deadline expires Monday night remains the only live question separating a managed crisis from a fully reignited war.
A Deal That Began Unravelling Almost Immediately
The Memorandum of Understanding signed by the US and Iran on June 17 was supposed to provide sixty days of relative stability during which negotiators could tackle the hardest unresolved issues: Iran’s nuclear program, the status of its frozen financial assets, and the long-term administration of the strait itself. The agreement called for lifting the US naval blockade, reopening the waterway to commercial traffic, and establishing a joint framework for safe passage that would involve both Iran and neighbouring Oman.
The latest exchanges mark an escalation in both the pace and geographic reach of attacks over the past week, throwing into question the interim US-Iranian agreement signed last month to reopen the strait and halt hostilities.
The deal began showing cracks within days of signing, as competing factions within Iran’s post-Khamenei government pulled in different directions, and as hardliners within the Revolutionary Guard resumed harassing commercial vessels using a southern corridor through Omani territorial waters that Washington had declared the safe alternative route.
Iran’s effective blockade of the strait has pushed up energy prices and increased concerns about inflation globally. The US completed “a new wave of offensive strikes against Iran” and struck “dozens of targets at multiple locations with precision munitions to degrade Iran’s ability to continue attacking international shipping flowing through the Strait of Hormuz,” US Central Command said Sunday.
‘They Always Break It’: Trump’s Frustration Spills Into the Open
US President Trump’s anger at the collapse of what he had publicly framed as a diplomatic triumph has been visible in both the tone and the content of his public statements over the past week.
“We had a deal. It was a done deal, and then they broke it. They always break it. We’ve had 10 deals with these people, and so we’re just going to hit them very hard,” he said in a phone interview on Fox News’ “Fox & Friends” program on Monday.
Iran’s top negotiator Mohammad Baqer Qalibaf gave as good as he got. “The era of one-sided deals is OVER. We told you: keep your word or pay the price. Reality is knocking,” Qalibaf posted on X on Sunday.
Iranian Foreign Ministry spokesperson Esmail Baghaei separately accused Washington of undermining the interim agreement, pointing to the US reinstatement of the blockade as proof that it was Washington, not Tehran, that had broken the deal’s terms first.
The Toll Proposal: Audacious, Possibly Illegal
US President Trump’s announcement that the US would charge a 20 per cent toll on all cargo shipped through the strait, effectively taxing every tanker that passes between the Persian Gulf and the Gulf of Oman, caught international lawyers and shipping executives off guard.
The United Nations’ International Maritime Organisation swiftly issued a statement rejecting the legal basis for any mandatory transit fee, saying no country has the authority to impose charges simply for passage through an international strait.
The IMO’s governing council reaffirmed that passage through the Strait of Hormuz must remain free of tolls under international law, including the organisation’s own founding convention.
The toll proposal also sits in awkward tension with the position the Trump administration itself had staked out just weeks earlier. Secretary of State Marco Rubio told reporters in June that “no country is allowed to charge tolls or fees on an international waterway,” a principle he articulated specifically to push back against Iran’s own proposals for managing strait traffic.
That the Trump administration now finds itself on the same side of the argument it previously attacked has not gone unaddressed by legal scholars or by Tehran’s foreign minister, Abbas Araghchi, who mockingly agreed with Trump’s logic while insisting Iran was the waterway’s true guardian and that 20 per cent was “of course too much.”
A Waterway Nearly Empty of Commercial Ships
The human and economic cost of the standoff is most starkly visible in maritime tracking data. Traffic along the Oman route dropped over the weekend “to minimal levels, indicating that operators continue to prioritise perceived security over more direct transit options,” ship-tracking website MarineTraffic said.
Just six commercial vessels transited the full length of the strait in the 24 hours preceding Monday’s blockade announcement, according to MarineTraffic data, compared with roughly 20 to 25 on a normal day before the war began. Several of those that did cross reportedly disabled their automatic identification system transponders mid-transit, going dark to avoid detection, a risk-management technique normally reserved for vessels entering active war zones.
Brent crude jumped by more than 4% on Monday on US President Trump’s latest comments and on fears of disruption to one of the world’s most important energy shipping routes, although prices remained below the peaks reached earlier in the conflict. Higher energy prices, particularly gasoline costs, are politically sensitive for Trump before congressional elections in November.
Pakistan’s Last-Minute Gambit
Even as the military posturing reached new intensity Monday, a quiet diplomatic channel remained open. US President Trump is reviewing a Pakistan-backed proposal for a two-week ceasefire and reopening of the Strait of Hormuz, according to Axios. Pakistan Prime Minister Shehbaz Sharif urged both the US and Iran to pause hostilities and reopen the Strait for two weeks. A senior Iranian official told Reuters that Tehran is “positively reviewing” the proposal. The proposal comes hours before Trump’s 8 p.m. ET deadline for Iran to end its blockade of Gulf oil shipments.
Trump has warned of strikes on Iranian infrastructure, including bridges and power plants, if no agreement is reached. Qatar and Oman have also been running separate diplomatic tracks aimed at preserving some form of the June memorandum, while the UN Secretary-General’s office has expressed deep alarm at the pace of escalation across the Gulf region in the past 72 hours.
The Deeper Struggle: Who Owns the World’s Oil Keyhole?
Beneath the rhetorical salvos and the competing toll proposals lies a fundamental question of sovereignty that no ceasefire agreement has yet resolved: who controls the Strait of Hormuz? Under the United Nations Convention on the Law of the Sea, ships have the right of transit passage through international straits used for international navigation, and coastal states, in this case both Iran and Oman, may not impede that passage.
Iran is not a signatory to UNCLOS and has long maintained that it has special authority over the waterway, a position the US has never accepted and has periodically enforced at gunpoint, most famously during Operation Praying Mantis in 1988, when the US Navy destroyed a significant portion of Iran’s fleet in a single day.
What is different now is that Iran has demonstrated a capacity to make the strait effectively unusable for commercial traffic even without physically blocking it, through a combination of missile strikes, drone attacks, mining threats and coordinated harassment of vessels, a level of operational access denial that has forced even the US Navy to acknowledge the limits of what it can protect in a narrow waterway flanked by Iranian territory on three sides.
The question of who emerges from Monday’s deadline as the waterway’s de facto guardian, regardless of what either side claims in public, may ultimately be answered not by declarations on Truth Social or posts on X, but by which side’s ships are still moving when the shooting stops.
