Officials say Yemen’s Iranian-backed Houthi rebels have captured a strategic island at the southern entrance to the Red Sea. The capture opens a new front in the Iran war and further threatens Saudi oil exports through one of the world’s key shipping lanes. The Houthis’ biggest territorial gain in years, along the Bab el-Mandeb Strait, could boost Iran’s strategy of driving up world oil and gas prices to pressure the United States. Saudi Arabia had no immediate comment but struck the airport in the nearby port city of Mokha that the Houthis seized Thursday. There were no reports of damage or deaths.