Bowen: Strait of Hormuz standoff raises risk of sliding back into all-out war

The ceasefire in the Gulf is four weeks old and showing its age. The US and Iran's determination to keep the pressure on each other has put it in serious jeopardy. This is a dangerous moment.

The ceasefire opened up a chance for diplomacy that looked for a short time as if it might make progress. Americans and Iranians faced each across a conference table in Pakistan's capital, Islamabad, but came away empty-handed.

The Pakistanis are trying to revive the process, without much success so far. Both America and Iran want to have a deal. But they have different deals in mind and are sticking to their red lines. Until one or the other, or preferably both, decide to offer concessions, renewed full-scale hostilities remain an incident away.

More than ever there is a strong risk of misperception and miscalculation of intentions and consequences. Both are classic ways in which crises slip out of control and wars escalate.

America's decision to escort two ships through the Strait of Hormuz was always going to produce a reaction from Iran. This week's urgent question is whether it ends there or whether more action and reaction power a slide back into all-out war.

Control of the Strait of Hormuz has become the central issue in the crisis. It was open to navigation, without restriction or the payment of tolls, until 28 February -when the US and Israel attacked Iran. Now Iran has demonstrated how closing it can mean everything from an offensive weapon to a revenue raiser and an insurance policy. This week, Iranian Foreign Minister Abbas Araghchi has told MPs that there will be no return to the old status quo.

The US cannot allow Iran to make the Strait of Hormuz into home waters that the Tehran regime can control and use to charge shippers millions in tolls, without accepting that tactical victory over Iran's armed forces has become a strategic defeat.

Closing the strait has global economic consequences. The length of time it stays closed will determine how severe the consequences of the war will be for people across the world. Shortages of oil and gas, as well as helium for high tech industries and feedstocks for fertiliser, are having an increasingly heavy impact on millions of people a long way from the war zone. The fertiliser crisis risks causing hunger in countries that do not have secure food supplies.

President Donald Trump's motives, declared and undeclared, are always complex and changeable. He has used social media to try to persuade oil traders not to drive up the price of petrol for American motorists.

He must also be frustrated by the Iranian regime's resilience and determination to resist however much pain America and Israel inflict on the country. A regime prepared to shoot its own citizens in the streets for protesting, as the Islamic Republic's security forces did once again in January, is not going to worry too much about their welfare - at least not until it affects their hold on power.