A South Korean cargo ship caught fire in the Strait of Hormuz on Monday. Within hours, the US military had sunk six Iranian naval boats, the United Arab Emirates was under missile attack for the first time since a fragile ceasefire took hold, and the American president was publicly pressuring Seoul to send warships to the Persian Gulf.

By Tuesday, Iran’s chief negotiator was warning that Tehran had “not even started” in its standoff over the strait. Oil prices had spiked past $115 a barrel. And South Korea — the country Trump most immediately called to his side — had offered a polite, firm maybe.

Monday’s events mark the most significant escalation since the US and Iran announced a ceasefire in early April, pausing — temporarily, it now seems — a conflict that began when the US and Israel attacked Iran on February 28. The core dispute has not changed: Iran wants the strait closed, the US wants it open, and the global economy is caught in the middle. What has changed is the tempo. Diplomatic friction has given way to kinetic engagement, and the coalition the White House needs to sustain its position is proving remarkably hard to assemble.

Project Freedom, under fire

President Trump announced “Project Freedom” on Sunday, describing it as a humanitarian effort to guide an estimated 2,000 stranded merchant vessels — carrying roughly 20,000 seafarers — out of the Persian Gulf through the Strait of Hormuz. The waterway, through which roughly 20 percent of the world’s oil and liquefied natural gas normally transits, has been effectively closed since Iran shut it in retaliation for the February attacks.

On Monday, the operation’s first day, two US Navy destroyers — the USS Truxtun and the USS Mason — transited the strait, supported by Apache helicopters and other aircraft. Iran responded with what Central Command described as a coordinated barrage of cruise missiles, drones, and small boats.

Admiral Brad Cooper, commander of US Central Command, told reporters that American forces sank six Iranian boats and defeated “each and every” incoming threat. Trump, characteristically, rounded up: “We’ve shot down seven small Boats or, as they like to call them, ‘fast’ Boats. It’s all they have left.”

Iran tells a different story. State media denied any combat vessels were hit and accused US forces of attacking “two small boats carrying people,” killing five civilians. Iran’s military claimed it fired warning shots at a US warship approaching the strait — a claim the US denied.

What is not in dispute is that the shooting was real, and it was intense.

The UAE draws fire

Iran also broke the ceasefire in a second direction with potentially broader consequences. The UAE said its air defenses engaged 12 ballistic missiles, three cruise missiles, and four drones launched from Iranian territory. A drone strike sparked a fire at the Fujairah oil facility, wounding three Indian nationals. An ADNOC-affiliated tanker was hit by two Iranian drones in the strait. In neighboring Oman, two foreign workers were wounded when a residential building was struck.

The UAE condemned what it called “renewed treacherous Iranian aggression.” French President Emmanuel Macron called the strikes “unjustified and unacceptable.” British Prime Minister Keir Starmer said the UK would continue to “support the defence of our partners in the Gulf.” Saudi Arabia, treading more carefully, called for de-escalation and “diplomatic efforts to reach a political solution.”

For Iran, the message was twofold: the strait remains closed on its terms, and any Gulf state facilitating the American operation can expect to be reminded of the cost. Iranian Foreign Minister Abbas Araghchi framed it differently: “Events in Hormuz make clear that there’s no military solution to a political crisis.” He called Project Freedom “Project Deadlock.”

The ally that won’t commit

It was against this backdrop that Trump turned to South Korea. The HMM Namu, a Panama-flagged, South Korean-operated cargo vessel, exploded and caught fire while anchored near the UAE. All 24 crew members — including six South Korean nationals — were unharmed, and the fire was extinguished. The cause remains unknown.

Trump was not interested in waiting for an investigation. “Iran has taken some shots at unrelated Nations with respect to the Ship Movement, PROJECT FREEDOM, including a South Korean Cargo Ship,” he wrote on Truth Social. “Perhaps it’s time for South Korea to come and join the mission!”

Seoul’s response was calibrated to the point of parody. The defense ministry said it would “carefully review our position” — a formulation that commits to nothing. Any decision, the ministry noted, would depend on international law, the safety of maritime routes, the US-South Korea alliance, and “the security situation on the Korean peninsula.” That last factor is doing considerable work: South Korea has a nuclear-armed neighbor to its north and little appetite for entanglement in a distant waterway, even at Washington’s request.

The exchange illustrates a structural problem for the White House. Project Freedom requires allied naval contributions — not for symbolic purposes, but because the US cannot indefinitely sustain a long-term escort operation through contested waters on its own. South Korea’s demurral is not an outlier. Germany’s chancellor called for Iran to return to negotiations. France condemned Iranian strikes but did not offer ships. Nobody is rushing to sign up.

A war by any other name

Trump’s own language has oscillated between calling the conflict a “war,” an “operation,” an “excursion,” and a “detour.” On Monday, he settled on “mini war.” The semantics matter: Congress has not authorized military force in Iran, and the War Powers Resolution requires the president to end unauthorized hostilities within 60 days. The administration argues the early April ceasefire satisfied that requirement — a legal claim Democrats contest.

Meanwhile, the economic stakes compound. Brent crude surged past $115 a barrel on Monday before easing slightly to $113.76 on news that a Maersk vessel, the US-flagged Alliance Fairfax, had successfully exited the strait under military escort. Iraq has reportedly slashed oil prices for buyers willing to run the Hormuz gauntlet, according to Bloomberg, as cited by France 24. The US has warned shipping companies they could face sanctions for paying Iran for strait transit.

What comes next

Iran’s latest peace proposal demands the US lift sanctions, end the naval blockade, withdraw regional forces, and cease all hostilities — including Israeli operations in Lebanon. Iran claims the proposal does not address its nuclear program. Trump has said Iran has “not paid a big enough price” for a deal.

Both sides are now testing how much pressure the other can absorb. Iran is demonstrating that it can widen the conflict — striking the UAE, threatening Oman, holding the strait closed. The US is demonstrating that it can force the strait open, at least for individual convoys, at significant cost in military resources and political capital.

The question neither side has answered is what happens when those demonstrations collide in earnest. Iran’s negotiator, Mohammad Bagher Ghalibaf, put it plainly: “We know full well that the continuation of the status quo is intolerable for America; whilst we have not even started yet.”

That is either a bluff or a threat. The distinction may not matter much to the 20,000 sailors still stranded in the Gulf, waiting to find out.

Sources