The expansion of the Iran war to the Red Sea has thrown the oil market another dangerous curveball, choking off a fragile recovery in energy flows. The global economy might increasingly respond to this escalation by slowing down. Nearly two weeks into the renewed conflict between the United States and Iran, tensions in the Middle East rose sharply after the Iran-backed Houthi militia on Monday declared a blockade against Saudi vessels seeking to pass through the Bab el-Mandeb Strait at the southern entrance to the Red Sea.