The Ship That Sailed: How the Second MOU Collapsed in Three Weeks

ANALYSIS · September 4, 2026 · 8 min read

On August 12, we wrote that the Second MOU was different from everything that came before it. Both presidents had signed. The route dispute that sank earlier attempts had a fix with real coordinates attached. For the first time, Washington had conceded the central question of the entire crisis — who actually controls the Strait of Hormuz.

Three weeks later, Secretary of State Marco Rubio was asked whether the United States might return to that agreement. His answer: "that ship, in many ways, has sailed."

It is worth sitting with how fast that happened. This is not a case of a deal slowly eroding over months, the way the June MOU did. This is a deal that held together, more or less, for barely three weeks before the underlying military logic of the war reasserted itself and swallowed it whole. Understanding how — and why — tells you more about the actual state of this conflict than either side's public statements do.

The Deal That Was Supposed to Hold

The case for the Second MOU's durability, as we laid it out in August, rested on three things: both heads of state had put their names on it, not just their negotiators; the shipping-corridor dispute that had derailed prior frameworks now had specific geographic coordinates attached rather than vague language; and Washington had, for the first time, effectively conceded that Iran held genuine leverage over the strait rather than treating Iranian control as a temporary irritant to be cleared by force.

That last concession mattered most. Every prior round of this conflict — the initial blockade, Project Freedom, the Northwood coalition, the Maritime Freedom Construct — had been built on the premise that the United States could simply out-muscle its way to an open strait. The Second MOU was the first framework that didn't assume that.

For about two weeks, the theory held. Iran and Oman advanced a parallel track: a temporary shipping corridor, then a revenue-sharing arrangement the IRGC itself confirmed on August 27. Qatar's prime minister visited Tehran to lend the framework diplomatic weight. It looked, briefly, like the war was migrating from the battlefield to a negotiating table with real technical specificity — mile markers, fee structures, joint mine-clearing commitments.

The Six-Month Mark Broke the Spell

The turn came, fittingly, on the war's exact six-month anniversary. On August 28, CENTCOM commander Admiral Brad Cooper announced that US forces had cleared the strait's main shipping lanes of mines entirely — upgrading what had been an unverified Trump claim into an official military declaration. It was framed as a milestone. It was also, in retrospect, the moment the two tracks of this conflict — the diplomatic one built around the Iran-Oman corridor, and the military one built around US assertions of control — stopped running in parallel and started running into each other.

Within 24 hours, Iran's IRGC Navy was publicly calling the American claim "an obvious lie." Iran's deputy foreign minister said the Oman understanding existed but would not be implemented until Washington honored the Islamabad memorandum. A tanker was struck near Khasab. None of this alone was new — variations on this pattern had repeated for months. What was new was the speed with which it escalated from there.

Three Days That Ended the Pause

On August 30, US forces struck two IRGC rocket launchers on Larak Island, citing evidence that Iranian personnel were preparing to fire mine-laying rockets into the strait — just two days after the demining announcement. It was the first direct US strike on Iranian territory in over a month, a pause that had held even as vessel attacks continued through it.

Iran did not wait long to answer. Within 24 hours, the IRGC fired ballistic missiles and drones at US bases in Jordan. The same night, two supertankers carrying Saudi oil — the Sidr and the Senegal Prosperity — were struck near Oman's Musandam Peninsula. Two Filipino seafarers aboard the Sidr were killed. Iran separately claimed, without naming a vessel, that two tankers had hit naval mines on an "unauthorized route" — a claim CENTCOM flatly denied, calling it disinformation. Three different accounts of the same 24 hours, none of them fully reconcilable: a Saudi tanker operator reporting a projectile strike with confirmed deaths, an Iranian military claim of a mine incident, and a US denial that any mine strike happened at all.

Then, on September 1, Trump approved what CENTCOM officials had been calling the "mow the lawn" plan — roughly 100 strikes across Iran, the largest single-day package since the Second MOU was signed. For the first time in the war, US drones struck Iranian government tankers directly, not to enforce the blockade against vessels attempting to run it, but as retaliation in its own right. Iran answered within hours: missiles at Jordan, drones at Bahrain and Kuwait, an attack on the US base at Erbil. Kuwait was hit again two days later.

Twelve days. That is the distance between a CENTCOM press release about cleared mines and the largest exchange of direct strikes since the war's active phase supposedly wound down in July.

The Casualty Numbers Nobody Fully Agrees On

What makes the last week difficult to write about cleanly is that even the basic facts of who has been killed are now contested on both sides.

Iran's health ministry initially said a US strike hit a wedding celebration in Hormozgan province, killing four and wounding dozens; CENTCOM disputed the account. By Thursday, one more of the wounded had died, and Iran's overall claimed toll from the September 1 strikes had risen to 18 killed and 108 injured — a figure Iranian state media has not clarified the scope of, and which no independent body has verified. Vice President JD Vance said he was "extremely skeptical" the wedding claim was accurate at all, and notably declined to describe the conflict as a war.

On the American side, the numbers are better documented but were, this week, badly mishandled. Commerce Secretary Howard Lutnick told CNBC on September 2 that "there haven't been American deaths" in the Iran war. That is false. Pentagon casualty data show 18 US service members killed and 767 wounded since February 28 — up from 758 wounded as of August 28 alone, meaning the toll has continued climbing even during what was supposed to be a diplomatic interlude. Lutnick apologized the next morning, saying he had confused the war with the administration's earlier Venezuela operation, in which no Americans died. Trump defended him in similar terms.

It is a small, almost bureaucratic-sounding episode next to strikes on tankers and airbases. But it matters for the same reason the Sidr/mine dispute matters: six months into a war this consequential, the two governments most responsible for informing the public about it cannot agree — and in Lutnick's case, apparently did not even accurately know — how many people have died fighting it.

What Rubio's Line Actually Tells Us

Rubio's comment that the MOU "has sailed" is worth reading carefully, because he did not simply say the deal was dead. He tied any future relief explicitly to Iran's nuclear program — territory well beyond what the Second MOU, which was fundamentally about shipping access and blockade terms, ever purported to resolve. That is a meaningful shift in what Washington says it's actually fighting for. The Second MOU was a transactional document about a waterway. Rubio's framing reopens the maximalist version of the conflict's aims that the MOU had, in effect, set aside.

It also lands in direct tension with where Iranian officials say they stand. President Pezeshkian told the Shanghai Cooperation Organisation summit on September 2 — the day before Rubio's remarks became widely reported — that Iran would "immediately reciprocate" if Washington returned to its commitments under the Islamabad memorandum. Whether that offer was sincere or rhetorical is impossible to verify from outside. What is verifiable is that the two governments are now describing two different conflicts: one where a return to negotiated terms remains available, and one where it has already sailed away.

What This Means Going Forward

The honest answer is that nobody outside the war rooms in Washington and Tehran knows whether this is a temporary spike — the kind the Strait of Hormuz crisis has produced roughly every six to eight weeks since February — or a genuine reversion to the war's earlier, more kinetic phase. The pattern of the last six months offers some reason for caution against either extreme prediction. Ceasefires here have a track record of collapsing in days; military escalations have a track record of settling back into an uneasy, expensive equilibrium.

What has changed, concretely, is the doctrine. "Tanker for tanker" — striking Iranian vessels in direct retaliation rather than only to enforce a blockade — is new, and it removes a distinction that had, until September 1, kept American naval action framed as defensive rather than punitive. Whether that distinction mattered much to Iran's own calculus is an open question. It mattered to how Washington described its own actions, and that description has now changed.

The Second MOU is not formally dead. No one has said so on the record, and Rubio's comment, however clear, is not the same as a government canceling an agreement. But the theory that made it durable in August — that both sides had genuine incentive to let a technical, transactional framework hold while the underlying dispute cooled — has not survived contact with a war that, six months in, still has no side willing to accept the terms on offer.