Iran and the United States sharply escalated their confrontation on Thursday, deepening a week-long crisis that has severely weakened last month’s truce. The renewed exchange of force suggested that the fragile pause in hostilities is close to breaking down altogether.

According to the available details, the United States carried out air strikes in southern Iran, and Iran answered with missile fire. The moves appeared to test the remaining limits of the truce and signaled a more dangerous phase in the standoff between Washington and Tehran.

Tensions also spread to vital maritime routes. After Iran resumed its blockade in the Strait of Hormuz, Washington responded by blockading Iranian ports. That escalation raised fresh concerns over regional shipping traffic, a key issue whenever security deteriorates around one of the world’s most important energy corridors.

Even so, one development pointed to a possible path away from further conflict: Iran’s release of a US citizen. While the military exchange showed how quickly the situation is worsening, that move offered a rare sign that some space for de-escalation may still remain.