‘Safe passage’: The fatal ambiguity at the heart of the Hormuz MoU

Lead

Barely three weeks after the United States and Iran signed a memorandum of understanding (MoU) meant to end their war, commercial shipping through the Strait of Hormuz is once again under threat. The US has resumed blockading Iranian ports, the two sides are trading strikes on bases and military assets across the Gulf, and President Donald Trump has floated the idea of charging shipping a 20 percent levy for the security of the strait. Many see this as the collapse of the June deal, but a maritime law expert argues it is the logical conclusion of an agreement whose central clause was written to be signed, not to be operated.

The MoU, signed on June 17, promised "safe passage of commercial vessels" through the strait, but the words commit each side to very little and permit each to believe very different things. That ambiguity, according to analysts and officials, is precisely why the arrangement is unravelling faster than even the pessimists expected.

Coverage comparison

The two news organisations whose reporting formed the basis of this article — Al Jazeera and the BBC — agree on the core problem: the MoU does not resolve the dispute over the Strait of Hormuz, and Iran and the US have different interpretations of what it requires. Both outlets note that the agreement was crafted with constructive ambiguity to secure signatures, and both point to a lack of clear implementation mechanisms as a key reason for its failure.

Al Jazeera's coverage, which includes analysis by the Chair of Maritime Law at City St Georges, University of London, emphasises that the agreement does not specify who administers the strait or what rules apply. The BBC's reporting, meanwhile, highlights that Iran sees the agreement as giving it control over the strait, while the US reads it as requiring Iran to open the corridor to global oil and gas supplies.

Where the sources diverge is in their framing. Al Jazeera's tone is critical, describing the agreement as flawed and doomed to fail, and using language such as "colourable claim" and "deterrence contest." The BBC maintains a neutral tone, presenting both sides' views without overt editorialising. Both outlets quote experts and officials, though Al Jazeera's analysis also draws on the author's own expertise.

Key claims

Different interpretations from the start. Both Iran and the US have understood the MoU differently from the beginning. Iran sees point five of the 14-point plan as a green light giving it sway over the management of the strait. The US reads the same clause as requiring Tehran to open the strait to the free flow of global oil and gas supplies, along with other vital commodities. As an Arab oil executive told the BBC: "You can drive a truck through those clauses."

The agreement does not specify who administers the strait. Article 5 of the MoU tasks Iran with making "arrangements using its best efforts" and then sends Tehran off to hold a "dialogue" with Oman and "discussions" with other Gulf states to define "the future administration and maritime services" of the strait. The US, the world's pre-eminent naval power, is not a party to those talks. Nor is the arrangement conditioned on the parties reaching any agreement, which means Iran could argue that, once it has talked, it may unilaterally announce a new regime.

Iran's theory of "innocent passage" is not supported by international law. The MoU's promise of "safe passage" is, as a matter of maritime law, almost empty. The clause leaves unanswered who administers the strait and what rules apply. Iran's claim that it can charge for passage is not supported by international law, which prohibits charges for mere passage.

Recent Iranian attacks on vessels were described as the work of a "rogue unit." Iranian attacks on three vessels, including a Qatari-flagged liquefied natural gas tanker moving through a shipping corridor close to Oman's coastline, were described by a diplomatic source in the region as the work of a "rogue unit" within the Islamic Revolutionary Guard Corps (IRGC).

Iran's parliament has introduced a new bill to manage the strait. The bill, introduced quietly, aims to manage the strait and reflects Iran's resolve to control it, particularly given what the BBC describes as Iran's "zero trust" in US promises.

The agreement has failed to deliver meaningful economic relief to Iran. Although commercial shipping through the strait, which carries roughly a fifth of global oil trade, initially recovered — with about 340 vessels passing through during the week of 22–28 June, the busiest period since hostilities began — the recovery was short-lived. Within weeks, ships were disappearing from the strait again, and Iranian exports, which had more than doubled from their wartime low under a temporary sanctions waiver, faced renewed disruption.

The MoU was meant to end the war and restore stability. The agreement was signed after weeks of military confrontation, extending the ceasefire and reopening a path back to negotiations. However, its implementation has been problematic due to the lack of clear mechanisms and leverage. The US and mediators appear to have focused on securing a mutually acceptable political text, with success measured by signatures and public declarations, rather than on the challenges of implementation.

Perspectives

Iranian government: Iran sees the agreement as giving it control over the Strait of Hormuz. The vague details of the MoU, specifically point five, are interpreted as a green light for Tehran to manage the critical maritime corridor. Iran's non-negotiable red line is that vessels must stick to its designated routes.

United States government: The US reads the agreement as requiring Iran to open the strait to the free flow of global oil and gas supplies and other vital commodities. Washington has also floated the idea of charging shipping a levy for the security of the strait.

Diplomatic and expert analysis: Analysts and officials point to the ambiguity of the agreement as a fundamental flaw. A maritime law expert argues that the clause on "safe passage" is "almost empty" as a matter of law, while Robert Malley of the International Crisis Group notes internal splits within Iran's leadership over how to proceed, with some wanting to cash in on battlefield gains through diplomacy and others believing the ceasefire came too soon.