U.S. Expands Iran Sanctions, Threatening Third-Party Firms; Tehran Vows Retaliation

Iran vowed retaliation on August 25, 2026, after the U.S. Treasury launched Operation Economic Outcast the prior day. Treasury Secretary Bessent called it an "economic onslaught." Expanded secondary sanctions force third-country firms to choose between the U.S. dollar system and Iranian commerce. Prior actions had already frozen $500 million. Iran has not specified its response.