“An agent persuaded a high-level Zetas operative to hand over the trackable cellphone identification numbers for two of the cartel’s most wanted kingpins, Miguel Ángel Treviño and his ​brother Omar.” For the DEA, this looked like an important break in their case against top drug cartel leaders. Instead, it triggered a long and deadly assault on a Mexican town near the Texas border. From ProPublica: How the US triggered a massacre In Mexico. This story provides a good reminder that the drug-related violence in Mexico is not isolated. It’s part of an ecosystem of horrors that includes, and is often driven by, actions in the US.

+ Men’s Journal: Confessions of a Cartel Hit Man.