Yemen’s Battleground Shifts in Favor of Iran-Backed Houthis

RIYADH—Houthi fighters allied with Iran have gained important new ground in the yearslong war in Yemen, as Saudi Arabia is struggling to defend a strategic, oil-rich city and U.S. efforts to broker peace stagnate.

Without coordinating with United Nations peacekeepers in the area, Yemeni forces supported by Saudi Arabia and the United Arab Emirates abruptly withdrew last week from key positions near the western port city of Hodeidah. At the same time, Saudi Arabia vowed to send more forces to defend Marib, the center of an energy hub near the Saudi border where the Houthis have been methodically gaining new ground for months.