UPDATE: US announces naval blockade of all Iranian ports starting Monday after Pakistan talks fail, sending oil above $100 and Asian markets tumbling as ceasefire teeters.
The United States will begin blockading all Iranian ports Monday afternoon after 21 hours of ceasefire negotiations in Pakistan ended without agreement, U.S. Central Command announced Sunday. The move sent oil prices surging above $100 a barrel and Asian markets tumbling as the fragile two-week truce appeared to collapse. President Trump said the blockade would target any vessel entering or leaving Iranian ports, though ships traveling between non-Iranian ports through the Strait of Hormuz would still be allowed to pass.
The announcement came after Vice President JD Vance led negotiations that ran through Saturday night in Islamabad, ultimately declaring Iran 'unwilling to give up its nuclear ambitions.' Iranian officials blamed 'excessive demands and unlawful requests' from Washington. Both sides appeared to believe they held the upper hand after weeks of inconclusive fighting that killed over 3,000 people in Iran and caused severe damage across the Middle East. Iran has maintained effective control over the Strait of Hormuz, through which roughly 20% of global oil flows, since the war began in late February.
The blockade raises major questions about enforcement and economic impact. Oil prices jumped 8% for U.S. crude to $104.24 per barrel and 7% for Brent crude to $102.29, reversing recent declines that came with ceasefire optimism. Asian markets opened sharply lower, with Japan's Nikkei down 1% and South Korea's Kospi falling 1.1%. Marine traffic data shows only about 40 commercial ships have crossed the strait since the ceasefire began, down from 100-135 daily passages before the war. Iran's Revolutionary Guard warned that military vessels approaching the strait would face a 'forceful response,' while Trump threatened to destroy Iranian infrastructure if attacks continue.
Editor’s rationale — Major institutional impact from announced U.S. military blockade of Iranian ports representing direct presidential action with immediate operational consequences; global scope affecting 20% of world oil transit and international shipping; long-term durability as foundational shift in U.S.-Iran military posture; primarily official announcements from CENTCOM and President Trump with strong verification, though some details lack independent confirmation.