Why has Trump threatened to bomb Oman — for a second time?

Dubai: US President Donald Trump has threatened to bomb Oman for the second time in four months — an extraordinary warning against a longtime American partner that has traditionally served as a bridge between Washington and Tehran.

This time, however, the immediate trigger is becoming clearer.

The Trump administration is unhappy with parts of an emerging agreement between Oman and Iran over how ships would move through the Strait of Hormuz, two regional officials briefed on the US position told the Associated Press.

Washington particularly objects to proposals for joint Iranian-Omani management of an exit route through the strait and Oman’s agreement to collect voluntary fees from vessels, even if those charges are for security and environmental services, according to the officials.

So why does an agreement intended to get ships moving again worry Washington?

At the heart of the dispute is a fundamental disagreement over who ultimately controls passage through Hormuz.

One of Washington’s objectives has been to prevent Iran from exercising control over the waterway, through which roughly a fifth of the world’s traded oil passed before the war.

An Iran-Oman arrangement could do the opposite.

Rather than forcing Tehran to relinquish control, joint management could formalise an Iranian role in deciding how vessels move through the strait.

Iran says it will not fully reopen Hormuz until the US lifts its blockade, releases frozen Iranian assets, removes oil sanctions and ends military operations and threats.

There is another complication: The US is not negotiating the emerging arrangement.

After US-Iran negotiations broke down, Tehran turned instead to Oman for direct talks over the future management of shipping.

Iran said Monday the two sides had reached an understanding on a new shipping route and were preparing a joint declaration.

Oman has not publicly said it intends to jointly control Hormuz with Iran.

But a deal struck without Washington could reduce US influence over how the world’s most important oil chokepoint operates.

Laleh Khalili, professor of Gulf studies at the University of Exeter, told Al Jazeera that an agreement reached without US involvement could expose the limits of Washington’s influence over events in Hormuz.

Washington and Tehran have repeatedly clashed over whether vessels should pay to use the strait.

US Secretary of State Marco Rubio warned in July against allowing Iran to impose tolls on shipping, while Trump has also insisted there should be no Iranian charges for passage.

Under international law, tolls cannot simply be imposed for passage through an international strait, although charges may be levied for specific services.

According to AP’s regional officials, Washington is unhappy even with Oman’s proposal for voluntary charges related to security and environmental protection.

That suggests the dispute is no longer simply about keeping Hormuz open. It is increasingly about who sets the rules once it is open.

That is what makes Trump’s language particularly striking.

Oman has maintained close relations with Washington for generations and has frequently acted as an intermediary between the US and Iran.

It helped mediate efforts to end the current war and has historically provided Washington with a channel to Tehran when direct communication was difficult.

Yet Trump warned Monday that the US could bomb Oman if it “gets in the way”.

It was not his first such warning.

In May, Trump said Oman would “behave just like everybody else, or we will have to blow them up”.

The latest threat therefore suggests Washington’s frustration with Muscat has been building as Oman pursues its own negotiations with Iran.

The stakes extend well beyond Oman.

Egypt said Tuesday that an Iran-Oman agreement could pave the way for Washington and Tehran to return to negotiations for a “comprehensive and permanent” settlement.

But Trump said Tuesday there were currently no talks with Iran and none scheduled.

Meanwhile, Tehran insists Hormuz will not fully reopen until Washington meets its demands.

Trump has escalated his rhetoric further by posting a map labelling the Strait of Hormuz “NEW U.S. Territory”, after previously floating the idea of declaring the waterway American territory.

Iran has dismissed that claim and insists the strait will remain under the sovereignty of the countries bordering it.

The emerging Oman-Iran deal therefore sits at the centre of a much bigger contest.

For Tehran, it could preserve a decisive role in Hormuz while providing a mechanism to restore shipping.

For Oman, it could offer a route towards de-escalation and eventually revive US-Iran diplomacy.

For Washington, however, the same agreement risks institutionalising precisely what it has spent months trying to prevent: Iran retaining significant influence over who moves through Hormuz — and on what terms.