Trump administration escalates 'Economic D-Day' against Iran with new sanctions targeting countries providing financial lifelines, while Iran threatens to halt regional oil exports and warns Gulf neighbors. Meanwhile, U.S.-Canada trade tensions explode with 50% tariffs sparking dollar-for-dollar retaliation threats. Iran's security chief threatened 'seismic' retaliation including attacking oil tankers through alternative Persian Gulf routes, potentially stopping all regional oil exports if Gulf states partner with U.S. economic restrictions.