The Strait of Hormuz is technically open. But what is now underway in the 34-kilometre chokepoint between Iran and Oman is not merely a shipping dispute — it is a contest over sovereignty, strategic leverage, and the future governance of the world’s most important energy corridor. Two parallel shipping routes are now operating in the same narrow strait: one endorsed by the United States, Oman and the International Maritime Organization; the other demanded by Iran’s Revolutionary Guards. Ships that choose the wrong route are being attacked. And the outcome of this contest will shape the region’s strategic order far beyond the current conflict.
How Two Competing Routes Emerged
The competing routes emerged directly from the ceasefire vacuum. On June 23, Oman announced that — along with the UN’s International Maritime Organization — it had established two temporary shipping lanes through the strait. The US encouraged ships to use the Omani route, while Iran insisted that all vessels must seek its permission before transiting the strait and use the route closer to its coastline.
On June 27, the Joint Maritime Information Centre overseen by the US Navy announced a widened route through the Strait of Hormuz near Oman, allowing increased naval traffic in both directions — a move explicitly framed as a challenge to Iran’s claimed control over the waterway.
Iran’s Islamic Revolutionary Guard Corps warned commercial vessels to only use routes through the Strait of Hormuz approved by Tehran. “The only authorised transit routes through the Strait of Hormuz are those designated by the Islamic Republic of Iran,” the IRGC stated, adding that ships must maintain contact with the IRGC Navy while transiting the waterway.
The Numbers: Which Route Ships Are Choosing
Iran’s latest attacks on commercial shipping came just as the United States and Oman were beginning to steer more vessels through the new southern shipping corridor hugging Oman’s coastline. Nearly half of inbound commercial traffic through the strait is already using that route, according to maritime intelligence firm Windward.
The pace of uptake reflects the industry’s practical calculation: the Omani route keeps vessels further from Iranian territorial waters, reduces exposure to IRGC interference, and has the backing of the world’s major maritime powers. But the attacks on vessels using that corridor — including the Singapore-flagged cargo ship struck last week — have introduced a new deterrent.
CBS News reported that tracking data showed three oil tankers heading toward the strait on the southern route near Oman’s coast turning back in the other direction. Three other ships that had also been on the southern route appeared to divert to the north, toward the route designated by Tehran.
Why This Is About More Than Oil
“The southern route creates a route they can’t toll or control,” retired Navy Rear Admiral Mark Montgomery told Fox News Digital. For decades, Iran’s ability to threaten shipping through the Strait of Hormuz has given it influence well beyond its borders. But that advantage is increasingly under pressure as Gulf states invest in pipelines that bypass Hormuz and the United States and Oman expand use of the southern corridor.
The strategic arithmetic is significant. Saudi Arabia has invested heavily in the East-West Pipeline linking Gulf oil fields to the Red Sea, while the United Arab Emirates has expanded export capacity through Fujairah, allowing crude exports to bypass Hormuz altogether. Every barrel that leaves the Gulf without transiting the strait — and every ship that safely uses the southern corridor — chips away at the leverage Iran has historically derived from one of the world’s most important maritime choke points.
This explains why Iran has responded to the Omani corridor with such force. If the southern route becomes normalised — if shipping companies, insurers and regulators treat it as the standard path through Hormuz — then Iran’s ability to use the strait as a pressure tool is permanently diminished, regardless of what any peace agreement says.
The Legal Question at the Heart of the Dispute
Oman’s statement framed the southern corridor as a temporary maritime option tied to freedom of navigation, international law and the law of the sea. On Thursday, US Secretary of State Marco Rubio framed the dispute as a test of Iran’s conduct rather than its rhetoric, effectively placing Washington behind the Omani-IMO route as an operational benchmark for safe passage through Hormuz. He warned that if Iranian rhetoric translated into threats against vessels or disruption of shipping, Washington would treat it as a violation of the ceasefire agreement.
Iran’s position rests on the legal reality that the Strait of Hormuz passes through the territorial waters of both Iran and Oman — making it, under a certain reading of international maritime law, subject to both nations’ navigation rules. The US and most of the world’s maritime powers take a different view: that the right of innocent passage through internationally recognised straits is absolute under the UN Convention on the Law of the Sea, regardless of whether those straits lie within a nation’s territorial waters.
What the MoU Says — and Doesn’t Say
Under the memorandum of understanding negotiated after the ceasefire, Iran, Oman and the Gulf littoral states are expected to negotiate the strait’s “future administration and maritime services” while commercial traffic moves toll-free for 60 days. President Trump has insisted on social media that there will be “NO TOLLS” after the negotiating period expires, even though the memorandum itself does not explicitly guarantee that outcome.
Iran has signalled a different vision. An IRGC-linked news outlet portrayed last-minute revisions to the agreement — including language governing the strait’s future administration and the temporary toll provision — as negotiating victories for Tehran.
The two sides are, in effect, operating from different texts — or at least from different interpretations of the same text. That ambiguity was built into the Versailles agreement and has now produced a physical confrontation in the strait itself.
What Happens If the Southern Corridor Holds
If the southern corridor becomes operationally established — if insurance markets accept it, if shipping lines treat it as standard, and if Iran’s attacks on corridor vessels fail to deter traffic — then the strategic landscape changes fundamentally.
Iran’s parliament has simultaneously been preparing a vote to enshrine Iranian sovereignty over the strait into law, according to the Hormuz Strait Monitor — a move that would harden Tehran’s legal position but which has no recognised effect under international maritime law.
The 60-day negotiating window is now the critical variable. If technical working groups in Switzerland can agree on a monitoring mechanism and a maritime governance framework before the deadline, a durable arrangement may still be possible. If not, the two-route standoff in the strait is likely to continue — and with it, the risk of further military confrontation.
