If Tehran embarked in “all-out war” with the United States it would bring down the Iranian regime, a retired four-star general has warned.
Jack Keane, once the US army's vice chief of staff, said President Donald Trump was likely to send the navy to the Arabian Gulf to protect ships and ensure the vital oil artery remains open.
"The Iranians don't want a war with the United States," Gen Keane told the BBC's Today programme. He said it would "would end their regime" and "everything that they have done in the last 39 years", including the export of the "Islamic revolution" to Lebanon Syria and Yemen, undermining Arab countries and developing nuclear weapons to preserve itself.
US Secretary of State Mike Pompeo has said Iran was “unmistakably” behind attacks on two tankers in the Gulf of Oman last week but insisted he does not want war.
Gen Keane said he expected limited military operations such as escorts similar to those conducted by the US in the late 1980s, when tension was also high with Iran.
“Those were limited military operations designed to get Iran’s attention and not clearly proactive in a sense of leading to an all-out war,” he said.
He said the US would probably ask its allies “to help support an escort mission ... to keep the oil flowing out of the Middle East”.
But Nathalie Tocci, a special adviser to European Union foreign policy chief Federica Mogherini, said Europe should not send extra ships to the Gulf and instead focus on trying to reverse the “vicious cycle”.
Iran viewed the US decision to pull of the Joint Comprehensive Plan of Action, the agreement to limit Tehran's nuclear strength, as an escalation and violation, she said. Ms Tocci warned of a real chance of “accidental” war being triggered through the retaliation cycle.
She added: “we still don’t have verifiable proof as to exactly what happened and who did what”, but conceded it was reasonable to believe Iran was behind the tanker attack.
It was recently revealed the UK is to send 100 elite Royal Marines to the Gulf to shore up its naval defences in the region.
On Tuesday Germany's leader, Angela Merkel, said "there is strong evidence" Iran was behind the tanker attack.
"It is a very serious situation," she added.