The Saudi-led—and U.S.-backed—war in Yemen turns two on March 26. The war, initially dubbed “Operation Decisive Storm,” and now more ironically called “Operation Restoring Hope,” has failed to achieve any of its aims. Yemen’s Houthi rebels, who Saudi Arabia erroneously claims are Iranian proxies, have retained control of northwest Yemen and Yemen’s unpopular government remains in exile. Saudi planes—which are dependent on mid-air refueling capabilities provided by the U.S.—have targeted bridges, roads, factories, hospitals, farms, and even funerals. Unexploded cluster munitions used by Saudi Arabia litter some of Yemen’s most productive agricultural land where they will kill and maim for...