Every day, millions of sailors, truck drivers, longshoremen, warehouse workers and delivery drivers keep mountains of goods moving into stores and homes to meet consumers’ increasing expectations of convenience. But this complex movement of goods underpinning the global economy is far more vulnerable than many imagined. Photo illustration: Adele Morgan Delivery drones are arriving, at last. After nearly a decade of largely unfulfilled hype about flying robots dropping orders at your doorstep, a handful of companies have started commercial operations in the U.S. involving dozens or hundreds of deliveries a day at each location. The companies are vying to be Americans’ choice when they want a bottle of Advil, a takeout meal, or the next iPhone delivered in under 30 minutes—once federal regulators enable broader rollouts. To Read the Full Story Continue reading your article with a WSJ membership