CAIRO – Tensions around the strategically critical Strait of Hormuz have exploded into a fresh escalation just days after a tentative de-escalation, as Iran rolled back its decision to reopen the waterway and opened fire on passing commercial vessels Saturday. The sudden reversal comes in direct response to the United States’ refusal to lift its sweeping naval blockade of Iranian ports, a move that has thrown fragile ceasefire talks into jeopardy and reignited fears of a widening regional conflict that could upend global energy markets.