President Donald Trump has ramped up US air strikes on Iran and threatened broader escalation, but there is little sign that a military strategy that has already failed to extract concessions from Tehran will succeed this time. With the collapse of an interim ceasefire deal reached a month ago, Trump finds himself in a bind as he seeks to break Iran’s grip on the vital Strait of Hormuz and force Tehran to accept his demands. While the two sides have so far avoided a return to full-scale...