WASHINGTON/DUBAI, Sept. 2 -- The US launched new air strikes on Iranian targets on Tuesday, quashing hopes that an exchange of fire last weekend might not lead to a wider renewal of hostilities. Tehran remained defiant, warning that it would prevent oil being exported from the Gulf, despite a threat by US President Donald Trump to hit Iran "hard" in response to the renewed Iranian strikes, and a warning from US Treasury Secretary Scott Bessent that Washington was about to impose new sanctions. P13...