June memorandum hands Iran leverage over Strait of Hormuz, shipping disrupted
June memorandum that recognised Iran’s role in the Strait of Hormuz has triggered attacks, US strikes and shipping diversions, raising energy and security risks.
The June 14 memorandum that sought to reopen the Strait of Hormuz has instead fuelled a struggle for control of the vital waterway, disrupting commercial shipping and driving fresh military strikes. The agreement’s language, which referenced Iran’s role in managing passage, is cited by Tehran as legitimising a stronger hand in the strait. Since the pact, attacks on vessels, U.S. counterstrikes and renewed threats to navigation have pushed shipping companies to reroute or delay transits through the corridor.
Cease-fire, covert escorts and a fragile reopening
In early April a tentative cease-fire reduced Iran’s attacks on commercial shipping, allowing some tankers to resume transit along a southern corridor near Oman’s coast. For two months U.S. naval forces provided covert guidance and periodic air cover while many commercial vessels switched off transponders to minimise detection. Those measures helped lift transit numbers from May into June, but they relied on informal arrangements rather than a durable security guarantee.
The June 14 memorandum formalised a framework for reopening the strait and paused a U.S. blockade while negotiations continued. Critics argue the document’s phrasing — notably the line urging Iran to “make arrangements using its best efforts for the safe passage of commercial vessels” — was vague and ripe for differing interpretation. That ambiguity now sits at the centre of the current crisis.
Terms of the memorandum and Tehran’s interpretation
At the heart of the dispute is a paragraph in the 14-point memorandum that called for Iran to consult with Oman and other littoral states about maritime services and administration in the strait. Iranian officials have pointed to that clause as recognition of an enduring role for Tehran in managing transit. Opponents contend the agreement effectively formalised a de facto shift in control without binding protections for neutral passage.
The memorandum prohibited tolls and fees for a 60-day period but did not embed a permanent, enforceable guarantee of free navigation. That limited window and the document’s nonbinding language have allowed Iran to assert discretion over routing while negotiations toward a broader deal continue.
Attacks, retaliations and the military response
After the June agreement, Iran struck vessels transiting the southern corridor and subsequently announced further attacks and the temporary closure of the waterway “until the end of U.S. interference in the region.” U.S. Central Command reported multiple strikes in response, marking a sharp escalation from the cease-fire period. The cycle of attack and counterattack has reduced weekly transits from nearly 400 ships in late June to just dozens in the immediate aftermath.
U.S. forces remain active in the Arabian Sea and adjacent waters, with mine-detection missions and a sizeable carrier presence intended to deter further aggression. American officials have warned there is no absolute guarantee that military guidance can prevent every threat to commercial vessels, underscoring the fragility of security for merchant shipping.
Shipping companies face a stark choice
Operators now confront two unpalatable options: follow the southern route near Oman and risk Iranian attacks, or take the northern corridor closer to Iran and submit to Tehran’s permission regimes and potential fees. During the peak of the hostilities, Iran demanded payments of up to $2 million per ship for passage along its preferred route, a practice it characterised as charges for safety and environmental services.
Rerouting and delays have immediate commercial consequences. Owners must weigh insurance costs, additional voyage time and the reputational and legal implications of complying with Iranian administrative demands. The resulting uncertainty has already contributed to price volatility in global energy markets.
Legal and economic stakes for Gulf and global markets
International legal frameworks governing straits and passage are central to the dispute, but Iran and some other states have taken divergent positions on how those rules apply. Tehran points to coastal-state rights and has created domestic structures such as the Persian Gulf Strait Authority to assert regulatory control. Critics say that amounts to contrived tolling inconsistent with customary freedoms of navigation.
Beyond legalities, the economic impact is immediate: roughly one-fifth of the world’s oil and liquefied natural gas normally transits the Strait of Hormuz. Market sensitivity to disruptions has already resurfaced, with energy prices reacting to the latest incidents and to the prospect of a broader collapse of the cease-fire. Policymakers must balance pressure to maintain open seas with the risk of deeper military confrontation that could more severely curtail supplies.
Regional diplomacy and the contest for influence
The memorandum was accompanied by talks toward a broader settlement, but its ambiguities have produced a competition for leverage between Tehran and the United States and their regional partners. Iran has sought bilateral dialogue with Oman and other Gulf states to formalise maritime arrangements, while Washington and allies push back against any permanent diminution of free passage. Nearby states, from the Gulf monarchies to international shipping registries, face urgent decisions about coordination and contingency planning.
As tensions rise, diplomatic channels remain active but strained, with both sides signalling they retain cards to play — economic measures, legal arguments and military options. The outcome will shape not only near-term shipping patterns but longer-term arrangements for governance of one of the world’s most strategic waterways.
The coming days will test whether the June memorandum can be renegotiated into clearer, enforceable protections for neutral navigation or whether Tehran’s interpretation becomes the dominant operating reality, forcing enduring change in how energy and goods move through the Strait of Hormuz.