U.S. triggers Iran port blockade; Brent crude re-enters $103/bbl

President Trump implemented a comprehensive shipping blockade of Iranian ports effective 10 a.m. ET on April 13, following the failed Islamabad negotiations. The measure isolates Iran-bound cargo while leaving Hormuz transit itself open. Iranian refinery throughput collapsed from 2.1 million bpd pre-blockade to 567,000 bpd, with Brent settling at $103.72/bbl by 9 a.m.