The Saudi-led coalition is hitting civilian targets, like factories, bridges and power stations, that critics say have no clear link to the rebels. In the rubble, the remains of American munitions have been found. SANA, Yemen — For decades, Mustafa Elaghil’s family produced snack foods popular in Yemen, chips and corn curls in bright packaging decorated with the image of Ernie from “Sesame Street.” But over the summer, a military coalition led by Saudi Arabia sent warplanes over Yemen and bombed the Elaghils’ factory. The explosion destroyed it, setting it ablaze and trapping the workers...