In January 2023, U.S. federal agents raided the home of a Tucson maintenance worker who had a side hustle hauling packages across the border to Mexico. They estimate that over the previous two years, the gray-bearded courier had ferried about 7,000 kilos of fentanyl-making chemicals to an operative of the Sinaloa Cartel. That’s 15,432 pounds, sufficient to produce 5.3 billion pills – enough to kill every living soul in the United States several times over. The chemicals had traveled by air from China to Los Angeles, were flown or ground-shipped to Tucson, then driven the last miles to Mexico by the freelance delivery driver. Even more astonishing is what fed this circuitous route: a few paragraphs buried in a 2016 U.S. trade law supported by major parcel carriers and e-commerce platforms that made it easier for imported goods, including those fentanyl ingredients, to enter the United States. This change to trade policy has upended the logistics of international drug trafficking. In the past few years, the United States has become a major transshipment point for Chinese-made chemicals used by Mexico’s cartels to manufacture the fentanyl that’s devastating U.S. communities, anti-narcotics agents say. Traffickers have pulled it off by riding a surge in e-commerce that’s flooding the U.S. with packages, helped by that trade provision. In short, a regulatory tweak fueling America’s online shopping habit is also enabling the country’s crippling addiction to synthetic opioids.