The US Treasury has announced expanded sanctions on Iran and warned that any country or entity helping Iran, including buyers of Iranian oil, payment facilitators and shipping services, could be cut off from dollar transactions. Chinese state banks are expected to comply quietly. For a Thai SME, the practical effects are indirect: payments in USD to or from Iran-linked counterparties may get blocked or delayed, banks may tighten checks on trade transfers, and shipping and fuel costs may stay volatile while the Strait of Hormuz remains disrupted.