If the Houthis were to gain control of the waterway on the opposite side of the Arabian Peninsula from the Strait of Hormuz, it could give their backer Iran a critical advantage in the war with the United States, reducing supplies through a second major transit corridor and sending oil prices surging. Saudi Arabia, the world’s largest oil exporter, has relied on the Red Sea route since the Iran conflict effectively closed Hormuz, through which a fifth of global oil used to flow. Yemeni government forces and their allies are relocating south along the Red Sea coast to Dhubab on the Bab el-Mandeb Strait, across from Perim Island, government military sources said. Control of Dhubab and the island is key to gaining hold of the strait, they said.