Iran’s seizure of a British tanker: dangerous waters ahead

The British-flagged Stena Impero tanker, seized last Friday in the strait of Hormuz, was at last notice held in the Iranian port of Bandar Abbas. But the ship of state known as HMS Britain is heading into uncharted waters, in the hands of an unreliable captain.

The new prime minister, who will walk into Downing Street on Wednesday, is almost certain to be the man who is regarded by many as the worst foreign secretary of recent times, and who has already demonstrated his keenness to keep the Trump administration happy. Probably the worst of the mistakes engendered by Boris Johnson’s sheer carelessness involved Iran: his claim that Nazanin Zaghari-Ratcliffe had been training journalists when detained there – not, as her family have always said, on holiday – was seized upon by the regime. She is still in jail. He is hardly known for learning from such lessons; short-term reassurance may come from the fact that unless a solution is found very rapidly indeed, this crisis will make it harder to replace Jeremy Hunt as foreign secretary, likely ensuring at least consistency.

The case of the Stena Impero is, of course, just the latest element of the broader US-Iran confrontation dragging others in. Germany’s foreign minister, Heiko Maas, warned Iran that the vessel’s seizure had contributed to an “escalation spiral” that could lead to war. But this spiral was initiated by the US, which chose to walk away from the nuclear deal, the JCPOA, by which Tehran was abiding, and Washington has done everything it can to destroy Iran’s economy – largely it seems from Donald Trump’s urge to erase Barack Obama’s legacy.

Tehran regards the impounding of the British tanker as a straightforward tit-for-tat response to the seizure of an Iranian oil tanker by Royal Marines two weeks ago; it came a day after a court in Gibraltar extended that vessel’s detention for another month.

Britain says it acted at Gibraltar’s request, over an alleged breach of EU sanctions on Syria. But the legal case is far from clear, to put it mildly, and US pressure is understood to have played a key role. The US national security adviser, John Bolton, who has long sought regime change in Tehran, exulted in the capture on Twitter. Add in the plentiful historical reasons for Iran to distrust the UK, and its anger that Europe has not mitigated the effects of US “maximum pressure”, and the scene was set for the Stena Impero’s seizure.

Iran is calibrating its actions. But has it measured carefully enough? It looks dangerously confident that the US president will refuse to be dragged into an expensive, lengthy, Middle Eastern war by Mr Bolton. Yet Mr Trump has come close to airstrikes, even if he called them off at the last minute, and he has bolstered the US presence in the region.

Though the UK will probably feel obliged to live up to its warning of “serious consequences” through some kind of measures, perhaps token sanctions, the most likely outcome for the Stena Impero may be a negotiated settlement leading to the release of both vessels. Meanwhile, Britain is considering how to protect its ships in one of the world’s key transit points, through which a third of all seaborne oil passes. But the underlying fear is that the new prime minister positions the UK closer to the US, and away from the European allies fighting to keep the JCPOA alive.

What happens in the strait of Hormuz offers only a taste of the challenges to come for a weakened and lonely vessel buffeted by an erratic US administration and its own decision to exit the EU.