It was time for after-school pickup at the San Francisco de Asís elementary school in downtown Guayaquil one recent afternoon when someone slotted pamphlets beneath the windshield wipers of the school’s minibuses. The message was cordial but ominous. “Greetings from the CJNG Group,” it said, misspelling the word “greetings.” “We want to come to an agreement: 6,000 to 4,500 Are we clear (sic).” At ...