Two months after US and Israeli strikes began, their war on Iran has settled into a costly stalemate.

The fighting has paused under a fragile Pakistan-brokered ceasefire, but the Strait of Hormuz remains blocked, direct talks have collapsed and neither side shows signs of yielding.

Last weekend, Washington’s envoys cancelled their planned trip to the Pakistani capital for further talks after Tehran declared it would not join negotiations until the US Navy ended its blockade of Iranian...