DUBAI/WASHINGTON — The U.S. launched new air strikes on Iranian targets on Tuesday, quashing hopes that an exchange of fire last weekend might not presage a wider renewal of hostilities. Oil prices had already risen after that first exchange of direct attacks since July and after reports of two tankers being hit leaving the Strait, the global oil supply waterway that Iran has effectively closed to shipping. Tehran remained defiant, warning that it would prevent oil being exported from the Gulf, despite a threat by U.S. President Donald Trump to hit Iran "hard" in response to the renewed Iranian strikes, and a warning from U.S. Treasury Secretary Scott Bessent that Washington was about to impose new sanctions. "Today at 12 p.m. ET (1600 GMT), U.S. forces began striking Islamic Revolutionary Guard Corps (IRGC) targets in Iran," U.S. Central Command posted on X. "The strikes follow recent attempted attacks by the IRGC against commercial shipping in the Strait of Hormuz and against American service members deployed to the region." Iran's state broadcaster said there had been reports of exp