US-Iran Talks Collapse Triggers Hormuz Blockade After 21-Hour Islamabad Failure

US-Iran ceasefire talks collapsed on April 12, 2026, after 21 hours in Islamabad, with Vice President JD Vance stating Iran rejected terms to dismantle its nuclear program. President Trump announced a naval blockade of the Strait of Hormuz on April 13, threatening global oil flows through the chokepoint handling 20% of seaborne crude exports. The move follows a two-week truce from April 8 and could drive oil prices above $100 per barrel amid market volatility.